Sequential infiltration synthesis apparatus and a method of forming a patterned structure

FIELD OF THE DISCLOSURE The present disclosure relates generally to apparatus and methods for manufacturing electronic devices. More particularly, the present disclosure relates to forming structures or layers on substrates using an infiltration apparatus.

As the trend toward smaller semiconductor device dimensions continues, various patterning techniques have emerged. These techniques include spacer-defined quadruple patterning, extreme ultraviolet lithography (EUV), and EUV combined with spacer-defined double patterning. Furthermore, directed self-assembly (DSA) is considered an option for future lithography applications. DSA involves the use of block copolymers to define patterns for self-assembly. Block copolymers used can include poly(methyl methacrylate) (PMMA), polystyrene, or poly(styrene-block-methyl methacrylate) (PS-b-PMMA). Other block copolymers can include new "high-Chi" polymers that could potentially enable smaller dimensions.

The above patterning techniques can utilize a penetrating material, such as an EUV polymer or DSA block copolymer resist, deposited on the substrate to enable high-resolution patterning of the substrate. To meet both the requirements of high resolution and low line edge roughness, the polymer resist can be a thin layer. However, such a thin polymer resist layer can have several drawbacks. In particular, high-resolution polymer resists can suffer from low etch resistance and high line edge roughness. This low etch resistance and high line edge roughness can make transfer to underlying layers more difficult.

Therefore, it may be advantageous to infiltrate a permeating material, such as a patterned material resist, to change the properties of the permeating material. To perform the infiltration, it may be advantageous to have a permeating device that can adjust the infiltration process.

According to at least one embodiment of the present invention, there is provided a sequential permeation synthesis apparatus including a reaction chamber constructed and arranged to hold at least a first substrate, a precursor delivery and removal system for providing and removing a gaseous first or second precursor to the reaction chamber, and a sequential controller operably connected to the precursor delivery and removal system, the sequential controller including a memory provided with a program that, when executed on the sequential controller, causes permeation of a permeation material provided on the substrate by activating the precursor delivery and removal system to provide and maintain the first precursor in the reaction chamber for a first time period T1, activating the precursor delivery and removal system to remove a portion of the first precursor from the reaction chamber for a second time period T2, and activating the precursor delivery and removal system to provide and maintain the second precursor in the reaction chamber for a third time period T3. The program in the memory may be programmed with the first time period T1 being longer than the second time period T2. The first period T1 for providing the first precursor may be programmed to be longer than the second period T2 for removing a portion of the first precursor, so that the first precursor has sufficient time to penetrate deeply into the infiltration material.

To ensure that only the first precursor permeates the permeable material and that there is no significant deposition on the permeable material, the second period T2 may be programmed to be long enough to remove the first precursor from the reaction chamber and also from the surface of the permeable material.

The second period T2 may be programmed to be long enough to remove the first precursor from the reaction chamber, from the surface of the infiltrating material, and partially from the pores of the infiltrating material, in this way the depth of infiltration may be adjusted.

According to a further embodiment, there is provided a sequential permeation synthesis apparatus comprising: a reaction chamber constructed and arranged to hold at least a first substrate; a precursor delivery and removal system for providing and removing vaporized first or second precursors to and from the reaction chamber; and a sequential controller operably connected to the precursor delivery and removal system, the sequential controller comprising a memory provided with a program that, when executed on the sequential controller, causes permeation of the permeation material provided on the substrate by: activating the precursor delivery and removal system to provide and maintain the first precursor in the reaction chamber for a first time period T1; activating the precursor delivery and removal system to remove a portion of the first precursor from the reaction chamber for a second time period T2; and activating the precursor delivery and removal system to provide and maintain the second precursor in the reaction chamber for a third time period T3.

A program in the memory is programmed to execute during a first time period T1, activate the precursor delivery and removal system to close the gas removal channel, provide a first precursor to the reaction chamber during a loading period LP, and activate the precursor delivery and removal system to close the first precursor channel while keeping the removal channel closed during a soak period SP, thereby ensuring economical use of the first precursor during the long first time period that may be required for the infiltration process.

According to a further embodiment, a method for forming a patterned structure or layer in a sequential infiltration synthesis apparatus is provided, the method comprising: providing a patterned infiltration material to a substrate at an upper portion within a reaction chamber; and infiltrating the infiltration material with the patterned infiltration material in at least one infiltration cycle. The infiltration cycle comprises activating a precursor delivery and removal system to provide and maintain a first precursor in the reaction chamber for a first period T1; activating the precursor delivery and removal system to remove a portion of the first precursor from the reaction chamber for a second period T2; and activating the precursor delivery and removal system to provide and maintain a second precursor in the reaction chamber for a third period T3. The first period T1 is longer than the second period T2. The patterned infiltration material may be a patterned photoresist or DSA material.

The first period T1 includes closing the gas removal channel to provide a first precursor to the reaction chamber during a loading period LP, and closing the first precursor channel to maintain the first precursor in the reaction chamber while keeping the removal channel closed during a soak period SP.

Thus, a sequential permeation synthesis apparatus may include: a first vaporizer configured and arranged to vaporize a hydrocarbon containing compound; a second vaporizer configured and arranged to vaporize a metal halide containing compound; a precursor delivery and removal system configured and arranged to provide a vaporized first precursor from one of the first or second vaporizers to a reaction chamber, provide a second precursor from the other of the first and second vaporizers, and remove the first and second precursors from the reaction chamber; and a sequential controller operably connected to the precursor delivery and removal system, the sequential controller having a memory provided with a program that, when executed on the sequential controller, performs permeation of a permeation material by: activating the precursor delivery and removal system to provide the first precursor to a permeation material on a substrate in the reaction chamber for a first time period T1; activating the precursor delivery and removal system to remove a portion of the first precursor from the reaction chamber for a second time period T2; and activating the precursor delivery and removal system to provide the second precursor to a permeation material on a substrate in the reaction chamber for a third time period T3. The first vaporizer may be configured and arranged to vaporize a metal hydrocarbon compound. The second vaporizer may be configured and arranged to vaporize a metal halide compound. The reaction between the infiltrating material, the metal hydrocarbon, and the metal halide may ensure that the amount of metal in the infiltrating metal may be optimized. The amount of infiltrating metal may provide the required etch resistance.

Certain objects and advantages of the present invention have been described hereinabove for purposes of summarizing the invention and the advantages achieved over the prior art. Of course, it should be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or performed in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein, without necessarily achieving other objects or advantages that may be taught or suggested herein.

All of these embodiments are intended to be within the scope of the invention disclosed herein. These and other embodiments will be readily apparent to those skilled in the art from the following detailed description of several embodiments, taken in conjunction with the accompanying drawings, and the invention is not limited to any particular embodiments disclosed.

It will be understood that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of the illustrated embodiments of the present disclosure.

<figref num="1">1 illustrates a sequential permeation synthesis device according to an embodiment.</figref><figref num="2A">2 illustrates an infiltration program according to at least one embodiment that may be executed by the sequential infiltration device of FIG. 1;</figref><figref num="2B">2 illustrates an infiltration program according to at least one embodiment that may be executed by the sequential infiltration device of FIG. 1;</figref><figref num="3">1 illustrates a reaction chamber of a sequential permeation device according to an embodiment.</figref><figref num="4">10 shows a reaction chamber of a sequential permeation device according to a further embodiment.</figref><figref num="5">1 illustrates a reaction chamber of a sequential permeation apparatus according to an embodiment including a batch reactor.</figref><figref num="6">2 illustrates an infiltration program according to at least one embodiment that may be performed by the sequential infiltration apparatus of FIG. 1 using an additional precursor delivery system.</figref><figref num="7A">1 shows secondary ion mass spectrometry (SIMS) measurements on layers infiltrated on a sequential infiltration device with different infiltration recipes.</figref><figref num="7B">1 shows secondary ion mass spectrometry (SIMS) measurements on layers infiltrated on a sequential infiltration device with different infiltration recipes.</figref><figref num="7C">1 shows secondary ion mass spectrometry (SIMS) measurements on layers infiltrated on a sequential infiltration device with different infiltration recipes.</figref><figref num="7D">1 shows secondary ion mass spectrometry (SIMS) measurements on layers infiltrated on a sequential infiltration device with different infiltration recipes.</figref><figref num="8">8a and 8b depict cross sections of infiltrated patterns on a sequential infiltrator with different infiltration recipes.</figref>

Although several embodiments and examples are disclosed below, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments and/or uses of the present invention, and obvious modifications and equivalents thereof. Therefore, it is not intended that the scope of the disclosed invention should be limited by the specifically disclosed embodiments described below.

FIG. 1 shows a sequential infiltration synthesis apparatus according to an embodiment. The apparatus comprises a reaction chamber 2 made of a suitable material, such as steel, aluminum, or quartz. A substrate 12 provided with an infiltration material on top thereof may be placed in the reaction chamber 2 on a substrate holder 10 by a substrate transporter through a substrate opening (not shown). The reaction chamber 2 forms a chamber closed at one end by a flange, through which gases are introduced via one or more openings provided with at least one (distribution) reaction chamber valve 19, which controls the opening and closing of said openings. The distribution reaction chamber valve 19 provides access to the reaction chamber 2 for the fluid distribution portions of precursor distribution and removal systems 3, 5.

The precursor distribution and removal system 3, 5 can provide a first or second precursor 28, 29 to the reaction chamber via a distribution reaction chamber valve 19. The first precursor 28 can be introduced into the chamber 2 as a gas by vaporizing a liquid or solid contained in a container 30 via a first precursor heater 32, which can provide a vapor pressure suitable for delivery to the chamber 2. The first precursor heater 32 can provide heat to the first precursor in the container 30. Similarly, the second precursor 29 can be introduced into the chamber 2 as a gas by vaporizing a liquid or solid contained in a container 31 via a second precursor heater 33, which can provide a vapor pressure suitable for delivery to the reaction chamber 2. As shown, the flow paths for the first and second precursors may be partially shared, or may be partially or completely separate. In the case of separate flow paths, a separate distribution reaction chamber valve 19 can be provided for each flow path.

The precursor distribution and removal system 3, 5 may include a purge system that provides a purge gas 34 to the reaction chamber 2 via a purge valve 24 and a distribution reaction chamber valve 19. The purge gas may be an inert gas, such as nitrogen, and may be used to purge the reaction chamber 2. As the purge gas flow paths are shown, the first and second precursors may have a partially common path, but may also be partially or completely separate. In the case of separate flow paths, a separate distribution reaction chamber valve 19 may be provided for each flow path.

Alternatively or additionally, the purge system may be constructed and arranged to provide purge gas directly to the reaction chamber 2 via a purge reaction chamber valve (not shown) that provides purge gas directly to the reaction chamber 2. By providing purge gas directly into the reaction chamber, the reaction chamber can be loaded with precursors using the precursor delivery and removal system while it is being purged, thus enabling increased throughput.

Optionally, a separate exhaust (not shown) from the precursor duct 18 to the pump 39 can be used to more effectively purge the precursor duct 18 while the distributor reaction chamber valve 19 is closed.

The reaction chamber may be closed at the other end by a flange that is connected to the gas removal portion of the precursor delivery and removal system through one or more openings provided with one or more reaction chamber valves 36, such as gate valves. A gas removal pump 39 may be part of the gas removal portion of the precursor delivery and removal system.

The reaction chamber 2 may be provided with an opening (not shown) for providing a substrate to the substrate holder 10. A door may be provided for opening and closing the opening to provide access by a substrate transporter to the substrate holder 12. The substrate holder may also form part of the reaction chamber 2 and be movable in a downward direction to provide access by a substrate transporter to the substrate holder 10.

The first precursor 28 may be a compound containing elements of the permeable material to be formed within the permeable material on the substrate 12. The first precursor 28 may be provided to the reaction chamber 2 via the first precursor valve 20 and the dispensing reaction chamber valve 19. FIG. 1 illustrates a system with two containers 30 and 31 containing the first and second precursors 28 and 29, respectively. However, the type of permeable material to be formed will determine the number of precursors and containers. For example, if a ternary permeable material is desired, the apparatus may include three containers and three precursor valves. The containers 30 and 31 may be bottles or other precursor sources as needed. For example, if one of the precursors may be solid, a container specially adapted to accelerate the sublimation of the solid precursor may be provided. One of the containers 30, 31 may also be provided with a gaseous precursor so that heating is not required.

A sequential controller 40, e.g., a microcontroller, may be operatively connected to one or more of the reaction chamber valves 19, 36, the precursor valves 20, 22, and the purge valve 24. The sequential controller 40 includes a memory M for storing a program that enables the apparatus to perform infiltration of an infiltration material provided with first and second precursors 28, 29 on a substrate 12 in the reaction chamber 2. A temperature sensor 26 may monitor the reaction chamber temperature. The temperature sensor 26 may also be provided with a pressure sensor. The temperature sensor may be operatively connected to the sequential controller 40 to optimize the infiltration process conditions. The program in the memory M of the sequential controller 40 may be programmed to sequence the opening and closing of the valves 19, 20, 22, 24, and 36 at the appropriate times to provide and remove the first and second precursors from the reaction chamber 2.

The apparatus may be provided with a heating system comprising a first heating element 14, for example, a heating resistance wire, and a heating controller 16, which may be operably connected to a temperature sensor 26. One or more of the temperature sensors 26 may also be provided with a pressure sensor. The heating controller may be operably connected to a sequential controller 40. The temperature sensor 26 may be used to measure the temperature within the reaction chamber 2 and provide feedback about this temperature to the heating controller 16 for adjusting the temperature of the heating element 14 and thereby adjusting the temperature of the reaction chamber 2. There may be additional temperature sensors to control the temperature within the reaction chamber 2 and/or the precursor delivery and removal system, providing multi-zone temperature control within the apparatus.

A pressure sensor may also be provided in addition to the one or more temperature sensors 26. The pressure sensor may be operatively connected to a sequence controller 40 for adjusting the processing sequence on the basis of the measured pressure.

The precursor supply flow duct between the (distribution) reaction chamber valve 19 and the reaction chamber 2 may be provided with a portion of the heating element 14. This portion of the heating element 14 along the precursor supply flow duct may be individually controlled by a temperature sensor 26 extending into the duct and a heating controller 16 to regulate the temperature of the precursor supply flow duct.

A portion of the heating element 14 may be provided in the precursor removal flow duct between the reaction chamber 2 and the (removal) reaction chamber valve 36. This portion of the heating element 14 along the precursor removal flow duct may be individually controlled by a temperature sensor 26 extending into the precursor removal flow duct and a heating controller 16.

In this way, cold spots that can cause condensation in the reaction chamber 2 can be avoided in the precursor supply flow duct and precursor removal flow duct. Condensation of precursors can prevent them from being effectively removed from the reaction chamber in time, and the condensate can then react with subsequent precursors to form particles that can contaminate the reaction chamber and substrate 12. Particles, especially in the flow paths that deliver precursors, can cause many problems.

The temperature may be set to an optimized process temperature. The rate of the infiltration process may scale with the pressure and time required for the first or second precursor to infiltrate into the infiltration material on the substrate, with infiltration proceeding more rapidly at higher temperatures. Therefore, processing at higher pressures is advantageous for reducing process time and maximizing throughput, but increases the risk of condensation. The optimized process temperature should be higher than the boiling temperature of the first or second precursor at the maximum pressure of the first or second precursor in the reaction chamber 2 to avoid condensation. By controlling the temperature from the reaction chamber 2 to at least one of the reaction chamber valves 19 and 36, the risk of condensation can be minimized.

For example, if the first or second precursor is trimethylaluminum (TMA), the vapor pressures will be as follows: 20°C about 9 Torr, 40°C about 25 Torr, 60°C about 64 Torr, 80°C about 149 Torr, 100°C about 313 Torr, 128°C about 760 Torr

As can be seen from these values, the process pressure can be increased substantially by increasing the temperature in the reaction chamber, but if there are small parts of the apparatus in contact with the precursor and have a slightly lower temperature, there is an immediate risk of undesired precursor condensation.

The interaction of TMA precursors with the infiltration material may be primarily through adsorption and diffusion. Temperature can have a significant effect on infiltration because the rates of adsorption and diffusion, as well as the equilibrium in the adsorption reaction, can be affected by temperature changes.

The permeation process may be optimal at 90°C, with permeation being less favorable for TMA at 120°C and 150°C. This may be expected for an adsorption-based process. At higher temperatures, the equilibrium of the adsorption reaction may shift toward separate TMA and polymer species. Therefore, preferred process temperatures are 20-450°C, preferably 50-150°C, more preferably 60-110°C, and most preferably 65-95°C.

The heating system may be configured and arranged to control the temperature of the reaction chamber and ducts from the reaction chamber to at least each reaction chamber valve at 20-450°C, preferably 50-150°C, more preferably 60-110°C, and most preferably 65-95°C. The sequential controller may be configured and arranged to reach and/or maintain a pressure of the first or second precursor within the reaction chamber, which may be 0.001-1000 Torr, preferably 1-400 Torr, more preferably 5-100 Torr, and most preferably 10-50 Torr, to avoid condensation during infiltration. In this way, an optimal process temperature and pressure for use with the precursor TMA can be achieved while creating a sufficient safety margin to avoid condensation within the apparatus.

The apparatus may include a direct liquid injector (DLI) including a liquid flow regulator and a vaporizer. The liquid flow regulator may control the flow of liquid to the vaporizer to vaporize the first or second precursor. Heating the liquid flow between the flow regulator and the vaporizer may not be necessary. The vaporizer may be heated to vaporize the first or second precursor. A heating system 16 may be configured and arranged to control the temperature from the reaction chamber 2 to the vaporizer to at least the boiling temperature of the first or second precursor at the pressure of the first or second precursor within the reaction chamber to avoid condensation. The vaporizer may be configured and arranged within the reaction chamber to provide vaporized precursor directly into the reaction chamber. The vaporizer may also be configured and arranged within the precursor distribution and removal system of the apparatus.

The precursor delivery and removal system may include a bubbler for providing the precursors. The bubbler may provide a discontinuous precursor flow having pulses of 0.1 to 200, preferably 1 to 3 seconds, of a first precursor alternating with pulses of 0.01 to 30, preferably 0.3 to 1 second, of a gas mixture.

1 , during typical operation, a first precursor 28 is infiltrated into the infiltrated material on the substrate by exposure to the first precursor 28 in the vapor phase from a reservoir 30. The first precursor 28 may react with the infiltrated material on the substrate to form a chemisorbed or physisorbed derivative that has infiltrated into the infiltrated material on the substrate. Thereafter, a second precursor 29 is infiltrated into the infiltrated material on the substrate by exposure to the second precursor 29 in the vapor phase from a reservoir 31. The second precursor 29 may react with the chemisorbed or physisorbed derivative of the first precursor 28 that has infiltrated into the infiltrated material on the substrate to form the final infiltrated material.

The containers 30, 31 for storing the first or second precursor may store a metal or an alkyl compound of boron. The metal may be aluminum, and the alkyl compound may be selected from the group consisting of trimethylaluminum (TMA), triethylaluminum (TEA), and dimethylaluminum hydride (DMAH).

The containers 30, 31 for storing the first or second precursor may store a metal halide compound, and the metal halide compound may be titanium (IV) chloride (TiCl), tantalum (V) chloride (TaCl), or the like.₅) and/or niobium pentachloride (NbCl₅) may also be used.

For zirconium or hafnium infiltration, the containers 30, 31 may be constructed and arranged to store a Zr or Hf precursor. The Zr or Hf precursor may include a metalorganic precursor, an organometallic precursor, or a halide precursor. In some embodiments, the precursor may be zirconium (IV) chloride (ZrCl₄) or HfCl₄In some other embodiments, the precursor is an alkylamine compound of Hf or Zr, such as TEMAZ or TEMAH.

The containers 30, 31 for storing the first or second precursor may store an oxidizer selected from the group including oxygen, water, or hydrogen peroxide, or a nitridizer selected from the group including ammonia and hydrazine.₂and water may be supplied through a supply line.₃is oxygen O₂It can be generated in a supply line and an ozone generator.

The apparatus includes a first container 31 for containing a first or second precursor such as an aluminum or boron hydrocarbon compound preferably selected from the group consisting of trimethylaluminum (TMA), triethylaluminum (TEA), and dimethylaluminum hydride (DMAH), dimethylethylamine alane (DMEAA), trimethylamine alane (TEAA), N-methylpyrrolidine alane (MPA), triisobutylaluminum (TIBA), tritertbutylaluminum (TTBA), trimethylboron, and triethylboron, and a first container 32 for containing a first or second precursor such as titanium(IV) chloride (TiCl), tantalum(V) chloride (TaCl), and a second precursor such as titanium(IV) chloride (TiCl).₅), and niobium pentachloride (NbCl₅), which may be preferred for infiltration of metal carbide materials.

Figures 2a and 2b illustrate an infiltration method according to at least one embodiment of the present invention for use in the apparatus of Figure 1. The method includes a first step 50 of providing a substrate to a reaction chamber with a substrate transporter, the substrate having at least one infiltration material thereon.

The permeable material may be porous. Porosity may be measured by measuring the voids in the permeable material as a ratio to the total volume of the permeable material and may have a value between 0 and 1. A permeable material may be qualified as porous if the ratio of voids to total volume is greater than 0.1, greater than 0.2, or greater than 0.3.

In one embodiment, the permeating material may be a patterned layer, such as a patterned resist layer. The resist layer may be annealed. The annealing step may have the purpose of outgassing moisture or other contaminants from the resist, hardening the resist, selectively burning away portions of the resist from the substrate surface, or creating desired porosity.

In one embodiment, the patterned layer can be provided by comprising a block copolymer film and promoting directed self-assembly of the block copolymer film to form the patterned layer. Infiltration of such a patterned layer can improve the quality of such a patterned layer. Block copolymer films, for example, have low etch resistance, and infiltrating the copolymer with a pattern can improve the etch resistance of the pattern.

In one embodiment, the patterned layer can be provided by having photoresist exposed in a lithography tool. Infiltration of such a patterned layer can improve the quality of such a patterned layer. For example, a patterned photoresist layer can have a low etch resistance, and infiltration of the patterned photoresist can improve the etch resistance of the pattern.

In one embodiment, the infiltrating material may be a polymer that fills gaps or openings in the structure and is then converted by infiltration into a metal oxide or metal. The polymer may be a polymer that was selectively grown on a specific surface of the substrate, for example, at the bottom of a gap. The polymer layer may be annealed. The annealing step may have the purpose of degassing moisture or other contaminants from the polymer, hardening the polymer, selectively burning off portions of the polymer from the substrate surface, or creating desired porosity.

During step 50 of FIG. 2a, after the substrate is positioned in reaction chamber 2 in FIG. 1, the reaction chamber and substrate can be sequentially purged by a program in memory M of controller 40 and evacuated from reaction chamber 2 by removal pump 39. If necessary, purge gas 34 can be provided by a purge system to flush reaction chamber 2 through purge valve 24, and distribution reaction chamber valve 19 and/or reaction chamber 2 can be heated to enhance outgassing. The program in memory M can be programmed to activate the precursor distribution and removal system to remove gas from reaction chamber 2 before infiltration begins, and to provide purge gas by the purge system to purge the reaction chamber for 1-4000 seconds, preferably 100-2000 seconds. The program in memory M can also be programmed to activate heater system 16 to heat reaction chamber 2 to a temperature of 20-450°C, preferably 50-150°C, and most preferably 70-100°C, to enhance contaminant outgassing.

The memory M of the sequential controller 40 may then be provided with a program that, when executed on the processor of the sequential controller 40, causes the permeation device to perform a permeation method 51 for permeating the permeation material during one or more permeation cycles. Each permeation cycle may include the following steps:

Step 52 includes providing a first precursor to the infiltrating material on the substrate in the reaction chamber for a first time period T1. The memory M of the sequential controller 40 may be provided with a program that, when executed on the processor of the sequential controller 40, causes the infiltrating device to close the purging valve 24 and the distribution reaction-chamber valve 19 and build up the first precursor in a duct of the precursor distribution and removal system upstream of the distribution reaction-chamber valve 19 by evaporating the first precursor 28 from the first container 30 by opening the first precursor valve 20 and having the first precursor temperature controller 32 activated to heat the container 32. The program in the memory M of the sequential controller 40 may then be programmed to briefly open the valve 19 to deliver the first precursor 28 to the reactor chamber 2.

This may be accomplished by opening the removal reaction chamber valve 36 and activating the removal pump to rinse the reaction chamber 2 with the first precursor during a flushing period FP, but may also be omitted. When the reaction chamber 2 is configured and arranged to accommodate a single substrate, the program in memory may be programmed to activate the precursor delivery and removal system during a flushing period FP of between 1 and 60 seconds, preferably between 2 and 30 seconds. When the reaction chamber is configured and arranged to accommodate 2 to 25 substrates, the program in memory may be programmed to have a flushing period FP of between 1 and 100 seconds, preferably between 2 and 50 seconds. When the reaction chamber is configured and arranged to accommodate 26 to 200 substrates, the program in memory may be programmed to have a flushing period FP of between 1 and 100 seconds, preferably between 5 and 50 seconds.

The first precursor may also be provided by the precursor delivery and removal system to the reactor chamber 2 during the loading period LP while not removing any precursor with the removal pump 39 by closing the removal reaction chamber valve 36 via a program installed in the memory M of the sequential controller 40. This results in a pressure buildup of the first precursor in the reaction chamber 2. This buildup may be terminated by the sequential controller 40 when the pressure of the first precursor or the second precursor in the reaction chamber 2 reaches a desired process pressure, preferably 0.001 to 1000 Torr, preferably 1 to 400 Torr, more preferably 5 to 100 Torr, and most preferably 10 to 50 Torr. Alternatively, there may be a pressure release valve that opens when the pressure in the reaction chamber increases above the predetermined desired process pressure, which may also terminate the loading period LP.

The first precursor may then be maintained stationary within reaction chamber 2 while the precursor delivery and removal system does not provide or remove any precursor during soak period SP. This can be done by sequential controller 40 closing reactor chamber valves 19 and 36 according to a program stored in memory M of sequential controller 40. When reaction chamber 12 is configured and arranged to accommodate a single substrate, the program in memory M can be programmed to activate the first precursor flow regulator for a load period LP of 1 to 3000, preferably 3 to 1000, more preferably 5 to 500 seconds, and a soak period SP of 10 to 9000, preferably 50 to 5000, more preferably 100 to 1000 seconds. When the reaction chamber 12 is constructed and arranged to accommodate 2 to 25 substrates, the program in the memory sequential controller can be programmed to have a load period LP of 1 to 3,000, preferably 3 to 1,000, more preferably 5 to 500 seconds, and a soak period SP of 10 to 12,000, preferably 15 to 6,000, more preferably 20 to 1,000 seconds. When the reaction chamber 12 is constructed and arranged to accommodate 26 to 200 substrates, the program in the memory M can be programmed to have a load period LP of 1 to 3,000, preferably 3 to 1,000, more preferably 5 to 500 seconds, and a soak period SP of 10 to 14,000, preferably 50 to 9,000, more preferably 100 to 5,000, and most preferably 100 to 800 seconds.

Thus, the first period T1 may include a cleaning period FP, a loading period LP, and/or a soaking period SP. During the entire period T1, the first precursor may penetrate and be absorbed within the permeation material. The memory M of the sequential controller 40 may be programmed with a program that, when executed on the processor of the sequential controller, causes the permeation device to provide the first precursor for the first period T1 for 1 to 20,000 seconds, preferably 20 to 6,000 seconds, more preferably 50 to 4,000 seconds, and most preferably 100 to 2,000 seconds. In this way, deep penetration of the first precursor within the permeation material is ensured.

In step 53, a portion of the first precursor is removed for a second time period T2. The program in memory M of sequence controller 40 may open removal reaction-chamber valve 36 and remove the first precursor from reaction chamber 2 using vacuum pump 38. Additionally or alternatively, purge gas 34 can be provided by a purge system to clean reaction chamber 2 by opening purge valve 24 and distribution reaction-chamber valve 19 with sequence controller 40.

The program in memory M of sequential flow controller 40, when executed on the processor of sequential controller 40, may be programmed to cause the permeation device to have a time period T1 during which the first precursor is provided to the permeation material that is longer than a second time period T2 during which a portion of the first precursor is removed. The program in memory M may be programmed with a first time period T1 that is 2 to 10,000, preferably 5 to 2,000, and more preferably 10 to 1,000 times longer than the second time period T2. The program in memory M may be programmed with a second time period T2 of 0.1 to 3,000, preferably 3 to 100, more preferably 6 to 50, even more preferably 8 to 30 seconds, and most preferably 10 to 25 seconds.

The second period T2 of step 53 may be sufficient to remove the first precursor from the reaction chamber, for example, 0.1 to 50 seconds, preferably 1 to 10 seconds, thereby causing infiltration into the infiltrating material and deposition on the infiltrating material.

Alternatively, the second period T2 may be selected to be long enough to remove the first precursor from the reaction chamber as well as the precursor from the surface of the infiltrating material. For example, if T2 is 1 to 1000 seconds, preferably 8 to 100 seconds, the infiltrating material may be left only permeated with the first precursor, and no significant deposition may remain on the surface of the infiltrating material after completion of step 53.

Alternatively, in step 53, the second time period T2 can be selected to be sufficiently long, for example, 2 to 3000 seconds, preferably 30 to 100 seconds, to remove the first precursor from the reaction chamber, from the surface of the infiltrated material, and also partially from the infiltrated first precursor within the infiltrated material. In this way, the penetration depth may be adjusted to result in a reduction in line width.

The reaction chamber 2 may be constructed and arranged to accommodate a single substrate, and the program in the memory M may be programmed with a first period T1 that is 2 to 6000, preferably 4 to 100, and most preferably 8 to 50 times longer than the second period T2. The first period T1 of such a reaction chamber may be 1 to 20000, preferably 20 to 4000, and more preferably 30 to 1000 seconds.

The reaction chamber 2 may be constructed and arranged to accommodate 2 to 25 substrates, and the program in the memory M may be programmed with a first period T1 that is 2 to 8000, preferably 10 to 500, and most preferably 20 to 200 times longer than the second period T2. The first period T1 of such a reaction chamber may be 1 to 16000, preferably 20 to 7000, and more preferably 30 to 1500 seconds.

The reaction chamber 2 may be constructed and arranged to accommodate 26-200 substrates, and the program in the memory M may be programmed with a first period T1 that is 2-10,000, preferably 10-2,000, and more preferably 20-1,000 times longer than the second period T2. The first period T1 of such a reaction chamber 12 may be 1-20,000, preferably 100-10,000, more preferably 200-6,000, and most preferably 300-4,000 seconds.

In step 54, the second precursor is provided to the reaction chamber 2 by the sequential controller 40 activating the precursor delivery and removal system to provide and maintain the second precursor in the reaction chamber for a third period T3. The memory M may be programmed with a third period T3 of 1 to 20,000 seconds, preferably 5 to 5,000 seconds, and most preferably 10 to 2,000 seconds.

The memory of the sequential controller 40 may be programmed to close the purging valve 24 and the distribution reaction chamber valve 19, open the second precursor valve 22 to build up the second precursor in the precursor distribution and removal system duct upstream of the distribution reaction chamber valve 19, and vaporize the second precursor 29 from the second vessel 31 by heating the second vessel 31. The program in the memory M of the sequential controller 40 may then be programmed to temporarily open the valve 19 to deliver the second precursor 28 to the reactor chamber 2.

The cleaning period FP, the loading period LP, and the soaking period SP have been described with the first precursor. The memory of the sequential controller may be provided with a program that, when executed on the processor of the sequential controller 40, will cause the permeation device to perform a third period T3 with the cleaning period FP, the loading period LP, and/or the soaking period SP as well. During the entire third period T3, the second precursor permeates the permeating material and reacts with the absorbed first precursor derivative within the permeating material, reinforcing the permeating material with the permeated material.

Optionally, the infiltration cycle may include step 55 of removing a portion of the second precursor during a fourth period T4. The sequential controller 40 may open the removal reaction-chamber valve 36 to remove the second precursor from the reaction chamber 2 using a vacuum pump 38. Additionally or alternatively, a purge gas 34 may be provided by a purge system to clean the reaction chamber 2 by opening the purge valve 24 and the distribution reaction-chamber valve 19 with the sequential controller 40. The fourth period T4 may be 0.1 to 3000, preferably 10 to 500, more preferably 30 to 250, and most preferably 60 to 200 seconds.

The program M may be programmed such that when the program is executed on the processor of the permeation device sequence controller 40, the permeation sequence may be repeated N times in a loop 56, where N is between 1 and 60, preferably between 3 and 20, and most preferably between 5 and 12.

The precursors 28 and 29 may be selected such that the precursor forms a metal or dielectric infiltrating material within the infiltrating material. The precursor vaporizes during infiltration and is preferably a gas.

The first precursor and the second precursor are utilized together in the apparatus of FIG. 1 to produce aluminum oxide (Al) according to the program of FIGS. 2a and 2b.₂O₃) silicon oxide, (SiO₂), silicon nitride (SiN), silicon oxynitride (SiON), silicon carbonitride (SiCN), silicon carbide (SiC), titanium carbide (TiC), aluminum nitride (AlN), titanium nitride (TiN), tantalum nitride (TaN), tungsten (W), cobalt (Co), titanium oxide (TiO₂), tantalum oxide (Ta₂O₅), zirconium oxide (ZrO₂), or hafnium oxide (HfO₂) can be used to infiltrate the infiltrating material.

Optionally, a permeating material such as a metal or dielectric may be overlaid by the permeating device over the entire volume of the permeating material, which may be done, for example, if the permeating material is patterned such that the pattern is wider and more etch resistant.

Patterned structures can be fabricated in the sequential infiltration synthesis apparatus of FIG. 1 by providing a patterned infiltration material to a substrate at an upper portion within reaction chamber 12 and infiltrating the patterned infiltration material with the infiltration material in at least one infiltration cycle. The patterned infiltration material can be a patterned photoresist or DSA material. The substrate can have a hard mask between the substrate and the patterned infiltration material. The hard mask can be spin-on glass, spin-on carbon, a silicon nitride layer, an antireflective coating, amorphous carbon, and/or a chemical vapor deposition (CVD) layer (e.g., a silicon dioxide oxide (SIOC) or amorphous carbon layer).

While the substrate remains in the sequential infiltration synthesis apparatus, the infiltration material can be removed while allowing the infiltration material to remain on the substrate. The infiltration material can be removed by heating the infiltration material to a temperature of 80 to 600°C, preferably 100 to 400°C, and most preferably 120 to 300°C. This allows for a reduction in the linewidth or linewidth roughness of the patterned structures of the infiltration material relative to the patterned infiltration material.

The infiltrating material may also be removed by providing a plasma to remove the infiltrating material in the reaction chamber. An oxygen or hydrogen containing plasma can be used to remove portions of the infiltrating material, and a plasma generator can be utilized to excite oxygen species to effectively remove portions of the infiltrating material. The plasma generator can include oxygen (O₂), or hydrogen (H₂) or alternatively, hydrogen (H₂) or oxygen (O₂) and nitrogen (N₂) can be provided. Thus, the etchant for removing the portion of the infiltrating material can include at least one of excited oxygen species or excited nitrogen species.

3 shows a sequential infiltration apparatus according to a further embodiment. A precursor distribution and removal system provides a first or second precursor from one side of the reaction chamber 2 through an inlet port 66. The inlet port can be closed with a valve 19. An outlet port 67 is provided to the distribution and removal system for removing the precursor from the reaction chamber 2.

The substrate holder 10 for holding the substrate 12 may be movable up and down. The substrate holder 10 is movable below the upper edge 68 of the reaction chamber 2 so that a substrate transport device (not shown) can provide or remove a substrate from the substrate holder 10. By moving it up, the reaction chamber can be closed again. The substrate holder 10 may be equipped with a third heating element for heating the substrate 12.

An advantage of the embodiment according to Figure 3 is that the reaction chamber 2 can have a small volume of 0.5 to 1 liter for a single substrate. The small volume allows for the use of low precursors. Therefore, the space between the substrate and the top of the reaction chamber can be less than 1 centimeter, preferably less than 5 mm, and most preferably less than 3 mm.

4 shows a sequential infiltration apparatus according to a further embodiment. The reaction chamber 2 includes a showerhead 69. The showerhead 69 may be provided at the top of the reaction chamber 2. The showerhead 69 may be connected to a precursor delivery and removal system to provide the first or second precursor 28, 29 to the surface of the substrate 12. The precursor delivery and removal system may remove the first or second precursor 28, 29 through an opening 67. A purge system may also be connected to the showerhead 69 to purge the reaction chamber 2.

The showerhead 69 may also be connected to a precursor distribution and removal system to remove the first precursor or the second precursor from the reaction chamber 2. The opening 67 may be connected to a purge system to purge the reaction chamber 2 in such cases.

The substrate holder 10 for holding the substrate 12 may be movable up and down. The substrate holder 10 may be provided with a third heating element (not shown) for heating the substrate 12. The advantage of this embodiment is that the showerhead rapidly provides and removes precursors from the surface of the substrate, while still allowing a volume of 2 to 5 liters, preferably 3 to 4 liters.

FIG. 5 shows a sequential infiltration apparatus according to a further embodiment. The apparatus includes a batch reactor chamber 70 with a volume of 50 to 200 liters and a capacity of 25 to 250 substrates. The substrates may be loaded into a boat 71 equipped with a substrate holder to accommodate 25 to 250 substrates using a substrate transporter. The boat 71 with the substrates may be moved into the reaction chamber 70 in a single loading operation by raising the boat into the reaction chamber through an opening at the bottom end of the reaction chamber. The bottom 71A of the boat 70 may seal the reaction chamber 70. A heating element 41 may be provided to control the temperature of the reaction chamber 70. First and second precursors may be provided at an inlet 72 and removed through an outlet 73 of the precursor distribution and removal system. Valves may be used to control gas flow, and care may be taken to ensure that the vaporized precursors are maintained above their boiling point within the reaction chamber 70. This may also be achieved by including heating elements to control the temperature within the inlet 72 and outlet 73, as well as the valves (e.g., reaction chamber valve 36).

If the apparatus includes a direct liquid injector system (DLI) including a liquid flow regulator and a vaporizer, the liquid flow regulator can control the flow of liquid to the vaporizer, which vaporizes the first or second precursor. There may be no need to heat the liquid flow between the flow regulator and the vaporizer. The vaporizer may be heated to directly vaporize the first or second precursor.

A vaporizer may be provided within the batch reactor chamber to provide the first or second precursor directly into the chamber. A batch reactor can infiltrate multiple substrates simultaneously, improving the throughput of the device.

After exposure, high-resolution polymer resists can suffer from low etch resistance and high line edge roughness. This low etch resistance and high line edge roughness can make migration to underlying layers more difficult. Therefore, it can be advantageous to infiltrate the patterned resist to change the properties of the resist. To perform infiltration, it can be advantageous to have a infiltrating device that can optimize the amount of metal infiltrated into the resist.

Thus, the system includes a reaction chamber 2 (see FIG. 1 ) configured and arranged to hold at least a first substrate 12 that is provided with a permeating material such as, for example, a patterned resist; a first vaporizer configured and arranged to vaporize a hydrocarbon containing compound; a second vaporizer configured and arranged to vaporize a metal halide containing compound; precursor delivery and removal systems 3, 5 configured and arranged to provide a vaporized first precursor from one of the first or second vaporizer to the reaction chamber, provide a second precursor from the other of the first and second vaporizers, and remove the first and second precursors from the reaction chamber; and a sequential controller 40. A sequential infiltration synthesis apparatus is provided, including a sequential controller operably connected to a precursor delivery and removal system and having a memory M provided with a program that, when executed on the sequential controller, executes the following steps to infiltrate an infiltration material on a substrate in a reaction chamber: activate the precursor delivery and removal system to provide a first precursor to the infiltration material on the substrate in the reaction chamber for a first time period T1; activate the precursor delivery and removal system to remove a portion of the first precursor from the reaction chamber for a second time period T2; and activate the precursor delivery and removal system to provide a second precursor to the infiltration material on the substrate in the reaction chamber for a third time period T3. The first evaporator may be configured and arranged to vaporize a metal hydrocarbon compound. The second evaporator may be configured and arranged to vaporize a metal halide compound.

The first and second vaporizers may be part of a precursor distribution and removal system 3, 5, which may provide first and/or second precursors 28, 29 to the reaction chamber via a distribution reaction chamber valve 19. The first precursor 28 may be introduced into the chamber 2 as a gas by vaporizing a liquid or solid contained in a container 30 by a first precursor heater 32 to provide a suitable vapor pressure for delivery to the chamber 2. The first precursor heater 32 may provide heat to the first precursor in the container 30. Similarly, the second precursor 29 may be introduced into the chamber 2 as a gas by vaporizing a liquid or solid contained in a container 31 by a second precursor heater 33 to provide a suitable vapor pressure for delivery to the reaction chamber 2.

Subsequently, after delivering the first and second precursors into the reaction chamber 2, the reaction between the infiltrating material, the metal hydrocarbon, and the metal halide can ensure that the amount of metal in the infiltrating material can be optimized to provide the required etch resistance.

During the second time period T2, removing a portion of the first precursor from the reaction chamber while providing the first and second precursors may be achieved by flushing the first precursor with, for example, an inert gas (nitrogen) and/or by pumping the first precursor out of the reaction chamber using the precursor distribution and removal system 3, 5. This may be necessary because the first and second precursors may otherwise react on the inner surfaces of the reaction chamber, forming particles and/or contaminants.

The first vaporizer may be constructed and arranged to vaporize an aluminum hydrocarbon compound as a metal hydrocarbon compound. The aluminum hydrocarbon compound may be selected from the group consisting of trimethylaluminum (TMA), triethylaluminum (TEA), triisobutylaluminum (TIBA), tritertbutylaluminum (TTBA), dimethylethylamine alane (DMEAA), dimethylaluminum hydride (DMAH), trimethylamine alane (TEAA), and N-methylpyrrolidine alane (MPA). The metal hydrocarbon compound may include a nitrogen atom.

The second vaporizer may be constructed and arranged to vaporize a metal halide compound containing titanium, hafnium, niobium, and/or zirconium. The halide may be a chloride. The metal halide may be titanium(IV) chloride (TiCl).₄), tantalum(V) chloride (TaCl₅), zirconium(IV) chloride (ZrCl₄), hafnium(IV) chloride (HfCl₄) and niobium pentachloride (NbCl₅) may be selected from the group consisting of

Trimethylaluminum (TMA) and titanium(IV) chloride (TiCl₄) may provide satisfactory metal concentrations in the infiltrated material, especially pure titanium(IV) chloride (TiCl₄) into the permeation material can be difficult.

The program in the memory of the sequential permeation synthesis apparatus may be programmed to activate the precursor delivery and removal system to remove at least a portion of the second precursor from the reaction chamber during a fourth period T4 after the third period T3. Removing a portion of the second precursor from the reaction chamber during the fourth period T4 after providing the second precursor may be accomplished by flushing the second precursor with, for example, an inert gas (nitrogen) and/or by pumping the second precursor from the reaction chamber using the precursor delivery and removal system. This may be necessary because the first and second precursors may otherwise react on the interior surfaces of the reaction chamber in subsequent process steps, forming particles and/or contaminants. Removal may be omitted if the second precursor is completely reacted without leaving any precursor in the reaction chamber and/or if the remaining first precursor is tolerated within the reaction chamber environment.

A program for performing permeation of a permeation material when executed on a sequential controller may be programmed to repeat at least a portion of a permeation cycle N times, where N is 1 to 60, preferably 1 to 10, and most preferably 1 to 5, e.g., 1, 2, 3, or 4. For example, a complete cycle of providing a first precursor in a first period T1, a first removal in a second period T2, a second precursor in a third period T3, and a second removal in a fourth period T4 can be repeated N times. Alternatively, a portion of a permeation cycle may be repeated N times, e.g., providing a first precursor in a first period T1, a first removal in a second period T2, followed by a second precursor in a third period T3, and a second removal in a fourth period T4. In this case, the first precursor is permeated only once while the second precursor is permeated multiple times. However, the opposite method is also possible, where the first precursor is permeated multiple times while the second precursor is permeated only once.

The sequential permeation synthesis apparatus may be provided with an additional precursor supply that provides additional precursors, and the precursor distribution and removal system may be configured and arranged to provide the additional precursors from the additional precursor supply to the reaction chamber and remove the additional precursors from the reaction chamber. The additional precursor supply may provide the additional precursor to the reaction chamber via the distribution reaction chamber valve 19 of FIG. 1 in a similar manner to how first precursor 28 can be introduced into chamber 2 as a gas by vaporizing a liquid or solid contained in container 30 using first precursor heater 32 to provide an appropriate vapor pressure for delivery to chamber 2. Thus, the additional precursor supply may be provided with an additional container and an additional precursor heater to provide an appropriate vapor pressure for delivery of the additional precursor to chamber 2. Alternatively, the additional precursor may be provided as a gas, eliminating the need for heating and vaporization.

FIG. 6 illustrates at least one embodiment of an infiltration program that may be executed by the sequential infiltration apparatus of FIG. 1 using an additional precursor supply system. In FIG. 6, items 50-56 are the same as the like-numbered items in FIG. 2a. Memory M of FIG. 1 provides a program for executing the infiltration of the infiltration material when executed on the sequential controller to activate the precursor distribution and removal system to provide additional precursor for a fifth period T5 after the fourth period T4 in step 55 to the infiltration material on the substrate in the reaction chamber in step 57. The additional precursor supply may include an additional container for storing an oxidizer selected from the group including oxygen, water, ozone, or hydrogen peroxide. Oxygen (O2) and water may be supplied via supply lines. Ozone (O3) may be generated by an ozone generator in the oxygen supply line and the additional precursor supply.

The memory may activate the precursor delivery and removal system to remove at least a portion of the additional precursor from the reaction chamber during a sixth time period T6 in step 58. Removal can be omitted if the second precursor is completely reacted without leaving any precursor in the reaction chamber and/or if residual first precursor is tolerated in the reaction chamber environment. The latter may be the case, for example, when water, nitrogen, or oxygen is used as the additional precursor.

A program that, when executed on the sequential controller, performs the permeation of the permeation material may be programmed to repeat at least a portion of the permeation cycle N times for additional precursors via 56, where N is between 1 and 60, preferably between 1 and 10, and most preferably between 1 and 5, e.g., 1, 2, 3, or 4. For example, the entire cycle of providing a first precursor in a first time period T1, a first removal in a second time period T2, a second precursor in a third time period T3, a second removal in a fourth time period T4, an additional precursor in a fifth time period T5, and a third removal in a sixth time period T6 may be repeated N times.

Alternatively, a portion of the infiltration cycle may be repeated, for example, by providing a first precursor in a first period T1 and a first removal in a second period T2, followed by providing a second precursor in a third period T3, a second removal N times in a fourth period T4, an additional precursor in a fifth period T5, and a third removal in a sixth period T6. In this case, the first precursor is infiltrated only once while the second and additional precursors are provided multiple times via optional shortcut 59. For example, TiCl₄In some cases, the first precursor may be infiltrated multiple times while the second precursor and the additional precursor are infiltrated only once. Alternatively, the first precursor and the second precursor may be infiltrated multiple times via any shortcut 60, while the additional precursor is infiltrated only once.

The memory of the sequential permeation synthesis device may be programmed with a first period T1 of 0.1 to 20,000 seconds, a second period T2 of 0.1 to 3,000 seconds, and/or a third period T3 of 0.1 to 20,000 seconds. The memory of the sequential permeation synthesis device may be programmed with a fourth period T4 of 0.1 to 3,000 seconds. The fifth period T5 may be programmed between 0.1 and 20,000 seconds. The sixth period T6 may be programmed between 0.1 and 3,000 seconds.

The sequential permeation synthesis apparatus may include a temperature control system constructed and arranged to control the temperature of the reaction chamber to a process temperature between 0 and 450° C. A pressure control system of the apparatus may be constructed and arranged to control the pressure in the reaction chamber to a process pressure between 0.001 and 1000 Torr.

One or both of the first and second vaporizers may include a heater for heating the first or second precursor. One or both of the first and second vaporizers may include an evaporator for evaporating the first or second precursor from a liquid. One or both of the first and second vaporizers may include a sublimator for sublimating the first or second precursor from a solid. A buffer volume may be provided between the reaction chamber and at least one of the vaporizers to buffer the vaporized precursor.

TMA and TiCl₄Examples

Infiltration of trimethylaluminum (TMA) into a single-wafer reaction chamber at a pressure of about 8 Torr can be achieved by infiltrating the first precursor for a first period T1 ranging from 1 to 2000 seconds, preferably 2 to 600 seconds, more preferably 4 to 400 seconds, and most preferably 6 to 200 seconds. At a pressure of about 8 Torr, for example, the memory may be programmed to activate the precursor delivery and removal system to open the first precursor flow path, close the gas removal flow path, and provide the first precursor to the reaction chamber for a 30-second loading period LP, and to activate the precursor delivery and removal system to close the first precursor flow path while maintaining the first precursor in the reaction chamber for a 20-second soak period SP, for a first period T1 of 50 seconds or less. It should be understood that these periods depend on the (partial) pressure of the first precursor and can be shortened by increasing the pressure, and that they depend on the size of the reaction chamber and can be shortened by decreasing the size of the reaction chamber.

The second period T2 may be selected from the range of 0.01 to 10,000 seconds, preferably 1 to 6,000 seconds, more preferably 5 to 4,000 seconds, and most preferably 20 to 2,000 seconds. It may be necessary to remove the first precursor from the reactor walls by purge and/or purging so that the reactor chamber can remain free of particles. In an optimized reactor, the first precursor can be prevented from adhering to the walls by other means, allowing for shorter purge/purging periods. Thus, in this example, a 4-minute purge was used, but a 20-30 second purge may be possible with an optimized system.

Titanium(IV) chloride (TiCl) at a pressure of about 8 Torr₄Infiltration of the second precursor in a single-wafer reaction chamber can be achieved by infiltrating the second precursor for a third period T3 ranging from 1 to 2000 seconds, preferably 2 to 600 seconds, more preferably 4 to 400 seconds, and most preferably 6 to 200 seconds. At a pressure of about 8 Torr, for example, the memory may be programmed to activate the precursor delivery and removal system to open the second precursor flow path, close the gas removal flow path, and provide the second precursor to the reaction chamber for a 30-second loading period LP, and to activate the precursor delivery and removal system to close the second precursor flow path while keeping the removal flow path closed for a 20-second soak period SP, maintaining the second precursor in the reaction chamber, for a third period T3 of 50 seconds or less. It should be understood that these periods depend on the (partial) pressure of the second precursor and can be shortened by increasing the pressure, and that they depend on the size of the reaction chamber and can be shortened as the size of the reaction chamber decreases.

Figures 7a-7d show secondary ion mass spectrometry (SIMS) measurements on photoresist layers infiltrated with different infiltration recipes. SIMS is a technique used to analyze the composition of solid surfaces and thin films by sputtering the surface of the sample with a focused primary ion beam and collecting and analyzing the ejected secondary ions.

Figure 7a shows the results of 100 s TMA and 100 s TiCl₄, and H₂SIMS measurements on a photoresist layer infiltrated with 5 cycles, without O and with N. The measured weight gain during infiltration was approximately 706 cm.²Δm = 2.9 mg per wafer surface. Figure 7a shows that significant amounts of aluminum and titanium have penetrated.

Figure 7b shows the results of 100 s TMA and 100 s TiCl₄, and H₂O without and N indicate SIMS measurements on a photoresist layer infiltrated with one cycle. The measured weight gain during infiltration was approximately 706 cm²Δm = 1.6 mg per wafer surface. Figure 7b shows that a significant amount of aluminum and some titanium has penetrated.

Figure 7c shows the results of 100 s TiCl4 and 100 s TMA, and H₂O without and N indicate SIMS measurements on a photoresist layer infiltrated with one cycle. The measured weight gain during infiltration was approximately 706 cm²The mass of the aluminum per wafer surface was Δm = 0.92 mg. Figure 7c shows that a significant amount of aluminum and some titanium has penetrated.

Figure 7d shows the 50-second TMA and 20-second H₂O and N indicate SIMS measurements on a reference photoresist layer infiltrated with one cycle. The measured weight gain during infiltration was approximately 706 cm²The average particle size per wafer surface was Δm = 0.6 mg.

As shown in Figures 7a-7d, the above process using TMA resulted in the formation of significant amounts of TiCl₄It may be possible to penetrate a penetrating material such as photoresist on a substrate, first TMA and then TiCl₄High mass uptake can be achieved by first infiltrating TiCl₄By infiltrating the cellulose with TMA, approximately 30% lower mass uptake can be achieved.₂High mass incorporation of penetrating O is achieved by first incorporation of TMA and then TiCl₄A mass about 50% lower than that obtained by

The metal can be uniformly infiltrated throughout the depth of the permeable layer, and TMA and TiCl₄There may not be significant formation of a crust on the infiltrated material when using a soft edge etching process. This may be advantageous when infiltrating a patterned layer that includes a polymer. The patterned layer may then be soft etched, for example with an oxygen plasma. The soft etching may lead to some shrinkage of the patterned layer. In the soft etching process, the polymer of the patterned layer may be removed to partially leave the metal within the layer. Soft etching of the patterned layer may lead to some shrinkage of the lines in the patterned layer and may also improve the line edge roughness (LER) of the lines. One or both effects of the soft edge etching may be desirable.

Figure 8a shows the same results as Figure 7a, with 100 s TMA and 100 s TiCl₄, and H₂No and N show cross sections of patterns infiltrated with five cycles. The top T part of Figure 8a shows the pattern before soft etching, and the bottom B part shows the pattern after soft etching. Shown is a slightly shrunk pattern, which may be desirable.

The sequential infiltration synthesis apparatus may be provided with an additional precursor supply that provides additional precursors, such as water, and the precursor distribution and removal system may be configured and arranged to provide water to the reaction chamber. Water may cause a crust to form on the infiltration material. This may be advantageous when infiltrating a patterned layer containing a polymer. The patterned layer may then be soft-etched. The soft-etching process may lead to some shrinkage of the patterned layer. The crust can protect the patterned layer from shrinkage, so if shrinkage is not desired, a crust formed with additional precursors, such as water, may be beneficial, and the line edge roughness (LER) of the lines may be improved by the crust.

Figure 8b shows the 100 s TMA and 100 s TiCl₄, and 20 seconds H₂O and N show cross sections of patterns infiltrated with five cycles. The top T of Figure 8b shows the pattern before soft etching, and the bottom B part shows the pattern after soft etching. Shown is a pattern that did not shrink when additional water precursor was included, which may be desirable.

During a sixth period T6, the additional precursor can be removed from the reaction chamber. Removal can be omitted if the additional precursor is completely reacted without leaving any precursor in the reaction chamber and/or if the remaining additional precursor is tolerated in the reaction chamber environment. The latter may be the case, for example, when water is used.

The specific embodiments shown and described are illustrative of the invention and its best mode and are not intended to limit the scope of the aspects and embodiments in any way. Indeed, for the sake of brevity, conventional manufacturing, association, preparation, and other functional aspects of the systems may not be described in detail. Moreover, the connecting lines shown in the various figures are intended to represent example functional relationships and/or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in an actual system and/or may not be present in some embodiments.

It should be understood that the structures and/or methods described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered limiting, as numerous variations are possible. The particular routines or methods described herein may represent one or more of any number of processing strategies. Thus, the various illustrated operations may be performed in the illustrated sequence, in other sequences, or in some cases omitted.

The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various processes, systems, and configurations, as well as other features, functions, operations and/or properties disclosed herein, and any and all equivalents thereof.