Vapor delivery device and method

0001The present disclosure relates to a steam delivery device, a method of manufacturing the same, and a method of using the same. In particular, the present disclosure relates to a high power, high volume delivery device for delivering a solid precursor compound to a reactor in the gas phase.

0002Semiconductors containing Group III-V compounds are used in the manufacture of many electronic and optoelectronic devices such as lasers, light emitting diodes (LEDs), and photodetectors. These materials are used to produce various single crystal phases with thicknesses ranging from a fraction of a micrometer to a few micrometers and of various compositions. Chemical vapor deposition (CVD) methods using organometallic compounds are generally used for the deposition of metal or semiconductor thin films, such as films of Group III-V compounds. Such organometallic compounds can be liquid or solid.

0003In the CVD method, the reaction gas stream is generally delivered to the reactor to deposit the desired film on the electron and optoelectronic devices. This reaction gas stream consists of a carrier gas saturated with precursor compound vapor, such as hydrogen. If the precursor compound is liquid, the reaction gas flow is obtained by passing (ie, bubbling) the carrier gas through the liquid precursor compound in the delivery device (ie, bubbler).

0004However, the solid precursor is placed in a cylindrical container or container and subjected to a constant temperature below its melting point to evaporate it. A carrier gas is used to accompany the precursor vapor and transfer it to the deposition system. For some materials, sublimation of the granular solid precursor by passing the carrier gas through the granular solid precursor can lead to the formation of cavities in the granular bed. The degree of the cavity changes according to the flow rate of the carrier gas. In general, no cavity formation is observed at very slow flow rates. At slow carrier gas flow rates, sublimation occurs on the surface of the granular solid, and the thickness of the sublimation layer is virtually zero, i.e. it is almost two-dimensional. As a result, the sublimation rate is uniform over the entire surface exposed to the carrier gas.

0005On the other hand, higher carrier gas flow rates push the boundaries of the sublimation layer deeper into the bed of granular solid precursors, and the thickness of the sublimation layer is no longer zero. The granular material is never substantially uniform, and as a result, the sublimation rate varies across the surface of the sublimation layer. Higher evaporation rates result in faster material erosion and cavitation. These cavities propagate in the general direction of carrier gas flow. Ultimately, the cavities form channels that penetrate the entire floor of the granular solid precursor. So the carrier gas bypasses the bed of granular solid precursors and stops controlled sublimation.

0006The formation of this channel results in low and unstable delivery rates when used in conventional bubbler-type solid precursor delivery vessels. Such a bubbler system can result in unstable and non-uniform flow rates of precursor vapors, especially when solid organometallic precursor compounds are used. Non-uniform metalorganic vapor phase concentrations adversely affect the composition of the membrane, especially the composition of the semiconductor membrane that grows in the organometallic vapor phase epitaxy (MOVPE) reactor.

0007Delivery devices have been developed that attempt to address the challenges of delivering solid precursor compounds to reactors. US Patent Application Publication No. 20080047607 to Horsky et al. Is a constant flow sublimation precursor vapor containing a solid precursor vaporizer, a mechanical throttling valve, a pressure measuring instrument and a steam conduit to a vacuum chamber. To a steam delivery system for delivering to a vacuum chamber. This steam delivery system includes a throttle valve based detection and control system that can provide a vaporizer temperature value set point to a vaporizer heater regulator that can maintain the vaporizer temperature at a set point. This detection and control system stores at least one predetermined valve displacement value that represents the desired conductance upper bound for the throttle valve.

0008The detection and control system monitors the position of the throttle valve, and when it detects that the valve is near or reaches the displacement value, the detection and control system sets the temperature value setting point. Raised to the regulator heater to generate increased steam generation and pressure upstream of this throttle valve, which allows the closed loop control of this throttle valve to return the valve to a substantially lower conductance position. To. The steam delivery system includes a reference table of predetermined increments of temperature rise suitable for operation, and when the detection and control system detects that the valve is near or reaches its displacement value. In addition, the vaporizer temperature setting point is effectively increased to the next step in the reference table. However, this system limits the flow of solid vapors to 0.1 standard cubic centimeters / minute (sccm) to 1 sccm, which is very low.

0009U.S. Patent Application Publication No. 2008/0044573 to Chen et al. Details methods for controlled delivery and monitoring of precursors from ampoules in process chambers. This method provides that a first carrier gas is flowed through a container containing a chemical precursor at a first flow rate to form a first precursor gas. In this method, the second carrier gas is combined with the first precursor gas at a second flow rate to form a second precursor gas, and the concentration of the chemical precursor in this second precursor gas is adjusted. It further involves measuring and calculating the mass flow rate of the chemical precursor.

0010However, this method suffers from some drawbacks. One of the drawbacks involves the use of opposite flow of the first carrier gas and the second carrier gas, which is non-uniform between the chemical precursor and the second carrier gas. Lead the mixture. Non-uniform sublimation of the solid precursor occurs when the pressure of the second carrier gas exceeds the pressure of the first carrier gas when opposed flows are used as specified by the chain. This in turn can lead to a heterogeneous supply of chemical precursors to the reactor.

0011This method suffers from the additional drawback of supplying a second precursor gas to only a single processing chamber. It cannot be used to feed the precursor to multiple reactors, because it is multiple to allow uniform delivery of the chemical precursor to each of the multiple reactors communicating with the delivery device. This is because it does not balance the competing demands from the reactor.

<p num="0012"><patcit num="1"><text>U.S. Patent Application Publication No. 20080047607</text></patcit><patcit num="2"><text>U.S. Patent Application Publication No. 20080044573</text></patcit></p>

<p num="0013"> Thus, an improved delivery device and method for delivering solid precursor vapor, in which the solid precursor is exhausted in the delivery device and the vapor concentration of the solid precursor remains uniform and sufficiently high. There is still a need for. It is also desirable to have a delivery device capable of delivering uniform, high flux precursor vapor throughout the process, from delivery device depletion of solid precursors, using carrier gas flows above 1 standard liter / min. ..</p>

<p num="0014"> Disclosed herein is a delivery system that includes a delivery device, a first proportional valve, a second proportional valve, a mixing device, a chemical sensor, and a first pressure / flow controller; said delivery device. Has an inlet port and an outlet port, the delivery device houses a solid precursor; the first proportional valve communicates with the inlet port of the delivery device, said first proportional. The valve operates to control the flow of a first flow of carrier gas to the delivery device based on the applied voltage; the second proportional valve communicates with the outlet port of the delivery device. The second proportional valve operates to control the flow of a second flow of carrier gas to the delivery device based on the applied voltage; the mixing device is the delivery device. It is downstream of and operates to mix the first and second streams; the chemical sensor is located downstream of the mixing valve and exits the mixing valve. Acting to analyze the chemical content of the incoming fluid flow, the chemical sensor communicates with the first proportional valve; the first pressure / flow controller is the chemical sensor and the first. The delivery system operates to deliver a substantially constant number of moles of precursor vapor per unit volume of carrier gas to multiple reactors. A plurality of reactors communicate with the delivery system.</p><p num="0015"> In the present specification, the first flow of the carrier gas is transferred to the mixing chamber via the delivery device, the delivery device contains the precursor compound, and the first flow of the carrier gas is 20 ° C. A temperature above C; a second stream of carrier gas is transferred to the mixing chamber, which is located downstream of the delivery device; and the first stream and the second stream. Also disclosed are methods comprising combining the flows in the mixing chamber to form a third flow, wherein the first flow and the second flow flow opposite each other before contacting each other. To.</p>

0016<figref num="1">FIG. 1 is a schematic representation of a typical delivery system, where the delivery device is in fluid communication with one or more mass flow controllers, and one or more mass flow controllers are in fluid communication with the reactor, respectively, and delivery. The steam from the device is deposited on a selected surface within the reactor.</figref><figref num="2">Figure 2 is a schematic representation of a typical delivery system, where a single pressure / flow controller controls the flow rate through the delivery device.</figref><figref num="3">Figure 3 is another schematic representation of a typical delivery system, where a single pressure / flow controller controls the mass flow through the delivery device.</figref><figref num="4">Figure 4 is another schematic representation of a typical delivery system, with a single pressure / flow controller controlling the mass flow through the delivery device and a first proportional valve located downstream of the delivery device. There is.</figref><figref num="5">FIG. 5 is a schematic representation of a typical mixing chamber.</figref><figref num="6">FIG. 6 is a schematic representation of another typical mixing chamber.</figref>

0017The present invention will be described more fully herein below with reference to the accompanying drawings showing various embodiments. Similar reference numbers refer to similar elements throughout.

0018If one element is said to be "above" another element, it can be directly above the other element, or understand that intervening elements may be between them. Will be done. In contrast, when one element is said to be "directly above" another, there are no intervening elements. As used herein, the term "and / or" includes any and all combinations of one or more of the related items listed.

0019In order to describe various elements, components, regions, layers and / or sections, terms such as first, second, third, etc. may be used herein, but these elements, components, etc. It will be understood that areas, layers and / or sections should not be restricted by these terms. These terms are used only to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, the first element, component, region, layer or section discussed below may be referred to as the second element, component, region, layer or section without departing from the teachings of the present invention.

0020The terms used herein are for purposes of describing specific embodiments only and are not intended to be restrictive. As used herein, the term "contains" identifies the presence of an indicated feature, region, integer, process, operation, element and / or component, but one or more other features, regions, integers, Does not preclude the presence or addition of processes, operations, elements, components and / or groups of these.

0021In addition, relative terms such as "bottom" or "bottom" and "top" or "top" are used herein to illustrate the relevance of one element to another, as shown in the drawings. Can be used in writing. It will be understood that the relative terms are intended to include the various directions of the device in addition to the directions depicted in the drawings. For example, if the device in one of the drawings is flipped over, the element described as being on the "bottom" side of the other element will eventually be oriented to the "top" side of that other element. Let's go. Thus, the typical term "bottom" can include both "bottom" and "top" directions, depending on the specific orientation of the figure. Similarly, if the device in one of the drawings is flipped over, the element described as "below" or "below" the other element will eventually be oriented "above" that other element. There will be. Thus, the typical term "down" or "down" can include both up and down directions.

0022Unless otherwise specified, all terms used herein (including scientific and technological terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be construed as having the same meaning as in the context of the relevant technology and disclosure, and are not explicitly defined herein. It will be further understood that the limits are not interpreted in an idealized or overly formal sense.

0023Typical embodiments are described herein with reference to a cross-sectional view which is a schematic representation of the idealized embodiment. As such, variations from the shape of the figure should be expected, for example as a result of manufacturing techniques and / or tolerances. Therefore, the embodiments described herein should not be construed as being limited to the specific shape of the region illustrated herein, but include, for example, differences in shape resulting from manufacturing. .. For example, the area illustrated or described as flat may typically have an undulating and / or non-linear structure. Further, the acute angles shown may be rounded. Thus, the areas illustrated in the drawings are essentially schematic, the shape of which is not intended to illustrate the exact shape of the area, and limits the scope of the claims of the present application. It's not intended.

0024The transitional term "contains" includes the transitional terms "consisting of" and "consisting of essentially".

0025Various numerical ranges are disclosed herein. These ranges include endpoints, as well as numbers between these endpoints. Numbers in these ranges are interchangeable.

0026Disclosed herein is a delivery system that includes a delivery device that communicates fluid with a reactor (including a mass flow controller and reaction vessel) via concentration and pressure sensors. The concentration and pressure sensors are in electrical contact with first and second pressure / flow controllers that control the flow of carrier gas through the delivery system, respectively. The delivery system uses a carrier gas stream, which is divided into two carrier gas streams: the first stream that flows into the delivery device and contacts the solid precursor compound; and the first that bypasses the delivery device. Flow of 2.

0027Dividing the carrier gas into two streams allows a lower flow rate in the first stream than in the second stream. The flow path of the entire first flow is also heated to high temperatures. When used in combination with high temperatures, the low flow rate in the first stream allows the entrainment of higher volumes of precursor vapor without forming channels and cavities. The amount of precursor vapor delivered per unit time across a plane perpendicular to the direction of flow is called the flux. In the present invention, the precursor vapor flux is higher in the first flow than the total carrier gas flow in the comparative system where there is no flow bypassing the solid precursor. This is due to the high temperature of the first stream. The high temperature of the first stream is accompanied by a higher concentration of precursor vapor when compared to a delivery system without detours (ie, the total volume of carrier gas passes through a vessel containing the solid precursor). It allows, while at the same time not forming channels or cavities in the bed of solid precursor compounds.

0028This delivery system functions to deliver uniform and constant concentrations of precursor vapor to multiple reactors. In another embodiment, the number of moles of precursor vapor delivered to the reactor per unit time is also kept constant.

0029The first stream containing the high concentration (flux) companion vapor and the second stream containing only the carrier gas contact each other downstream of the delivery device to form a third stream. Since the second flow has a higher flow rate than the first flow, the formation of the third flow by the combination of the first flow and the second flow results in more than a comparative device that does not use a detour. It results in the delivery of high flux precursor vapor to the reactor. As mentioned above, delivery of high flux precursor vapor to the reactor is achieved without the formation of channels and cavities in the solid precursor. In addition, the dew point of the third stream is below the temperature of the piping and hardware connecting the delivery system to the reactor, eliminating condensation (deposition of solid precursors inside the connecting piping).

0030By reducing the steam concentration in the third stream, the dew point of the steam is lowered, steam condensation does not occur at the connecting line, and a constant proportion of steam to the carrier gas can be supplied to the reactor. The delivery system allows the dew point of the steam to be adjusted, which is usually adjusted with reference to the temperature of the line that transports the carrier gas to the delivery device.

0031The delivery system is advantageous in delivering uniform and high flux precursor vapor from the delivery device throughout this process until the solid precursor is depleted. It allows carrier gas of 1 standard liter / minute or more, specifically 2 standard liters / minute or more, and more specifically 3 standard liters / minute or more to flow into the reactor. It is a flux of precursor vapor at a temperature of 60 ° C and a pressure of 900 torr at a rate of more than 1,500 micromol / min, specifically more than 1,750 micromol / min, more specifically 2,000 micromol / min. Can be delivered.

0032This delivery system is also advantageous because it can simultaneously deliver precursor vapor to be delivered to multiple reactors. This delivery system can reconcile competing requirements from multiple reactors and provide each reactor with a stream with uniform concentrations of precursor vapor, regardless of volume requirements from individual reactors. .. This delivery system is capable of delivering a substantially constant concentration of precursor vapor to each reactor. In certain embodiments, the concentration of precursor vapor per unit volume is no more than 3% over a period of 2 minutes to 60 minutes from the selected value, specifically 2 minutes to 60 minutes from the selected value. It varies by an amount of 2% or less over a period of minutes, and more specifically by an amount of 1% or less over a period of 2 to 60 minutes from the selected value.

0033This delivery system is unique in that it does not utilize opposing flows in the absence of any mixing chamber. In other words, this delivery system does not use flows that come into contact from opposite directions. The system can use opposed flows only if any mixing chamber is used.

0034As mentioned above, this delivery system uses a mixing chamber. In certain embodiments, a mixing chamber may be used if the delivery system does not use opposed flows. The interaction between the carrier gas and the precursor vapor in the mixing chamber aids in better mixing and thus ensures uniform delivery of the precursor vapor to the reactor. In another embodiment, the mixing chamber is used only if this delivery system uses opposed flows.

0035Here, referring to FIG. 1, the delivery system 100 includes a delivery device 102, which communicates with the mass flow controller 208 and the reactor 200, and the pressure sensor 106, respectively, via a chemical sensor 104. The chemical sensor 104 and the pressure sensor 106 are in operative communication with the first pressure / flow controller 108 and the second pressure / flow controller 110, respectively. Each, the first pressure / flow controller 108 is in operational contact with the first proportional valve 112, while the second pressure / flow controller 110 is in operational contact with the second proportional valve 114. There is. In a typical embodiment, the first pressure / flow rate controller 108 is in electrical communication with the first proportional valve 112, respectively, while the second pressure / flow rate controller 110 is in second. It is in electrical contact with the proportional valve 114.

0036Proportional valves 112 and 114 operate to control the flow of carrier gas through the delivery system 100 when they are located upstream of the delivery device 102. The proportional valve 112 can be located downstream of the delivery device and can operate to control the flow of carrier gas and precursor vapor. Shut-off valves 116, 118, 120 and 122 are used to isolate the various components of the delivery device. In certain embodiments, the shut-off valves 116 and 118 are normally operating and open.

0037When the voltage to the proportional valves 112 and 114 is increased, the valve opening is increased, which increases the flow of carrier gas through this valve. On the other hand, when the voltage to the proportional valve is reduced, the valve opening is reduced, which reduces the flow of carrier gas through this valve.

0038In one embodiment, the chemical sensor 104, the first pressure / flow controller 108, the first proportional valve 112 and the delivery device 102 are a first closed loop comprising a first flow 202 of carrier gas. To form. The first stream 202 of carrier gas is directed to the inlet port (not shown) of delivery device 102. This first stream is also referred to as the "source flow" stream because it contacts the solid precursor compound and accompanies the precursor vapor within the delivery device 102. It is generally maintained at high temperatures, as one of the functions of the first stream is to accompany the precursor vapor. However, this high temperature is below the melting point of the precursor compound contained within the delivery device 102.

0039The first flow is generally maintained at a temperature of 20 ° C to 80 ° C, specifically 30 ° C to 75 ° C, specifically 40 ° C to 70 ° C. The first flow 202 is accompanied by vapor of the precursor compound while uniformly depleting the surface of the solid precursor compound with which the first flow comes into contact. This prevents the formation of channels and cavities in the mass of solid precursor compounds.

0040In another embodiment, the pressure sensor 106, the second pressure / flow controller 110, the second proportional valve 114, and the delivery device 102 are a second closure that includes a second flow 204 of carrier gas. Form a loop. The second flow 204 of the carrier gas is directed to the outlet port of the delivery device 102. This second flow bypasses the solid precursor compound in the delivery device, so it is also referred to as the "bypass flow" flow.

0041The first flow 202 after exiting the delivery device 102, together with the second flow 204, forms a third flow 206, which enters the reactor 200 via the mass flow controller 208. The first flow 202 joins the second flow 204 downstream of the outlet valve 122. The third stream 206 contains a desired amount of precursor vapor in the carrier gas. Dividing the carrier gas into two streams allows the first stream to be heated before entering the delivery device. As mentioned above, the first flow 202 and the second flow 204 do not face each other. In certain embodiments, the first flow 202 and the second flow 204 flow in the same direction. In another embodiment, the first stream 202 and the second stream 204 meet each other at an angle of 1-90 degrees to form a third stream 206, which enters the reactor 200.

0042In certain embodiments, any mixing chamber 107 may be used to combine the flows from the first flow 202 and the second flow 204. In the mixing chamber 107, the flows from the first flow 202 and the second flow 204 can be introduced in opposite directions. In another embodiment, a mixing chamber 107 is used to combine the flows from the first flow 202 and the second flow 204 if the respective flows are not flowing in opposite directions. sell. Both of these embodiments will be described in detail later.

0043By combining the first flow 202 with the second flow 204 to form the third flow 206, the concentration of the precursor vapor in the carrier gas is reduced, resulting in a lower dew point of the precursor vapor. To do. As a result, the vapor accompanying the carrier gas does not undergo precursor vapor condensation even when it encounters a lowered temperature. This allows a constant proportion of precursor vapor to the carrier gas supplied to the reactor. In another embodiment, by lowering the dew point of the precursor vapor in the third stream below the ambient temperature, precursor vapor condensation does not occur and a constant proportion of the precursor vapor to the carrier gas is present in the reactor. Can be supplied to.

0044The first and second closed loops cooperate and interact with each other to control the delivery pressure and precursor vapor concentration to one or more reactors 200. The flow rate of the precursor to each reactor is controlled by the mass flow controller 208 associated with each reactor. The first and second closed loops also cooperate and interact with each other to keep the dew point of the precursor vapor below ambient temperature. This interferes with the condensation of the precursor vapor and allows the transfer of higher amounts of the precursor vapor to the reactor at a higher mass flow rate than other comparatively commercially available systems. Although each loop has been shown to be a closed loop in FIG. 1, it is also intended that some of these loops may be open loops, if desired.

0045Again, with respect to FIG. 1, the delivery device 102 has an inlet valve 120, which can be used to start or stop the flow of carrier gas to the delivery device 102. The delivery device 102 also has an outlet valve 122, which can start and stop the flow of carrier gas with precursor vapor from the delivery device 102 to the reactor 200. As can be seen in FIG. 1, the delivery device 102 is in fluid communication with the reactor 200 so that the precursor vapor from the delivery device 102 is deposited on the selected surface in the reactor 200. The mass flow controller 208 allows the desired flow of the mixture into the reactor 200.

0046The mass flow controller 208 and reactor 200 can include a single mass flow controller and reactor, or multiple mass flow controllers and reactors (not shown). In a typical embodiment, the mass flow controller 208 and the reactor 200 include a plurality of mass flow controllers and reactors.

0047The delivery device 102 includes an inlet port (not shown) and an outlet port (not shown) through which carrier gas enters through this inlet port, and carrier gas with precursor vapor passes through this outlet port. Is sent to the reactor 200. The inlet port of the delivery device 102 is in fluid communication with the inlet valve 120, while the outlet port of the delivery device 102 is in fluid communication with the outlet valve 122. The delivery device 102 generally contains a filling material (not shown) and a solid precursor compound (not shown). The filling material is generally placed between the solid precursor compound and the inlet port.

0048In certain embodiments, the delivery device 102 is surrounded by a heating jacket 103, which functions to keep the delivery device 102 at a high temperature. The heating jacket 103 can be heated by a fluid (eg, a steam jacket) or by electrical energy. The heating jacket 103 functions in system 100 to maintain the temperature of the gas stream (ie, carrier gas and precursor vapor) above 20 ° C at all times. The heating jacket 103 maintains the precursor compound in the delivery device 102 at a temperature of 20 ° C to 80 ° C. In certain embodiments, all pipes or tubes used to transfer the carrier gas to the delivery device are maintained at a temperature of 20 ° C to 80 ° C.

0049The delivery device 102 and the inlet and outlet ports can be made from a material that is not degraded by the carrier gas or solid precursor compound and also does not alter the composition of the carrier gas or solid precursor compound. It is also desirable that this material withstand the temperature and pressure of operation. The enclosure can be made from suitable materials such as glass, polytetrafluoroethylene and / or metal. In certain embodiments, the housing is made of metal. Typical metals include nickel alloys and stainless steel. Suitable stainless steels include SS304, SS304L, SS316, SS316L, SS321, SS347 and SS430. Typical nickel alloys include INCONEL, MONEL and HASTELLOY.

0050Various filling materials (not shown) can be used for delivery device 102, except that the filling material is inert to the solid precursor compound and cylinder under the conditions of use. In general, it is desirable that the filling material be fluid. For example, as the solid precursor compound is depleted from the cylinder, the level of the solid precursor compound in the cylinder will decrease and the filling material will need to flow to fill some depression on the surface of the precursor compound layer. Suitable filling materials include ceramics, glass, clay, organic polymers and combinations containing at least one of the above. Examples of suitable ceramic filling materials include alumina, silica, silicon carbide, silicon nitride, borosilicates, alumina silicates, and combinations containing at least one of the above.

0051Filling materials can be of various shapes such as beads, rods, tubes, horseshoe shapes, rings, saddles, discs, saucers, or other suitable shapes such as needles, crosses, and spirals (coils and spirals). Can be mentioned. Various combinations of shapes can be used if desired. Filling materials are generally commercially available from a variety of sources. The filling material can be used as is, but it can be cleaned before use.

0052The delivery device 102 generally includes an opening (not shown) through which the solid precursor is introduced. The solid precursor material can be added to the delivery device by any suitable means. The solid precursor compound can be added to the delivery device 102 in powder form or can be fritted (this is discussed below). The volume ratio of solid precursor compound: filling material can vary over a wide range, for example 10: 1 to 1:10. In some embodiments, this volume ratio is 1: 4 to 4: 1.

0053Solid precursor compounds are the source of precursor vapor. Suitable solid precursor compounds for use in steam delivery systems can be used within the delivery device. Suitable precursor compounds include indium compounds, zinc compounds, magnesium compounds, aluminum compounds, gallium compounds and combinations containing at least one of the above compounds.

0054Typical solid precursor compounds include trialkylindium compounds such as trimethylindium (TMI) and tritersial butylindium; trialkylindium-amine adducts; dialkylhaloindium compounds such as dimethylchloroindium; alkyldi. Haloindium compounds such as methyldichloroindium; cyclopentadienylindium; trialkylindium; trialkylalcin adducts such as trimethylindium-trimethylalcin adduct; trialkylindium-trialkyl-phosphine adducts such as trimethyl Indium-trimethylphosphine adduct; alkyl zinc halide, eg, ethyl zinc iodide; cyclopentadienyl gallium; ethylcyclopentadienyl zinc; allan-amine adduct; alkyldihaloaluminum compounds, eg, methyldichloroaluminum; alkyldi Halogallium compounds such as methyldichlorogallium; dialkylhalogallium compounds such as dimethylchlorogallium and dimethylbromogallium; biscyclopentadienyl magnesium (Cp)₂Mg); Carbon tetrabromide; Metal beta-diketonate, eg, beta-diketonate of hafnium, zirconium, tantalum and titanium; Metal dialkylamide compounds, eg, tetrakis (dimethylamino) hafnium; Silicon compounds and germanium compounds, eg, bis (Bis (trimethylsilyl) amino) germanium can be mentioned. In the solid precursor compound, the term "alkyl" is (C).₁-C₆) Alkyl. A mixture of solid precursor compounds can be used in this delivery device.

0055The solid precursor compound can be fritted. As used herein, "fritting" refers to the fusion of solid precursor compounds. The frit of the solid precursor compound in the delivery device allows for a more consistent and stable concentration of precursor compound in the gas phase, and the solid precursor from the cylinder compared to other prior art or other commercially available devices. It has been found to result in better depletion of compounds. The "frit of a solid precursor compound" refers to a fusion cake of a solid precursor compound having a substantially flat top surface and sufficient porosity to allow carrier gas to pass through the cake. In general, when the frit of the solid precursor compound is first formed, the frit matches the inner dimension of the cylinder, i.e., the frit has a width substantially equal to the inner dimension of the inlet chamber. The height of the frit will vary depending on the amount of solid precursor compound used.

0056As long as the carrier gas does not react with the solid precursor compound, a suitable carrier gas can be used with the delivery device 102. The specific choice of carrier gas will vary depending on various factors, such as the precursor compound used and the specific chemical vapor deposition system used. Suitable carrier gases include inert gases . Typical gases are hydrogen, nitrogen, argon, helium and the like.

0057The chemical sensor 104 is a concentration sensor and measures the concentration of precursor vapor in the carrier gas. The chemical sensor 104 continuously monitors the gas concentration and controls the first flow 202 through the delivery device 102, which is the main source of concentration changes and / or drifts, thereby causing the precursor vapor to the reactor. Control the mass transfer rate.

0058In certain embodiments, the chemical sensor 104 is an in-line acoustic binary gas concentration sensor used to detect the ratio of precursor vapor to carrier gas. The chemical sensor produces an acoustic signal that is transmitted through a gas mixture (ie, a mixture of the vapor of the precursor compound and a carrier gas) and uses digital signal processing technology to accurately time the transmission of that acoustic signal. Measure. The transfer time is then used to calculate the concentration of precursor vapor in the carrier gas based on its physical properties. This concentration measurement provides data that allows control of the mass transfer rate of the precursor vapor while compensating for any variation in the concentration of the precursor vapor with respect to the carrier gas. This control of mass transfer rate is provided by the first proportional valve 112.

0059For example, if the output from the chemical sensor 104 is zero volt, it indicates that the concentration of precursor vapor in the carrier gas is 0% by weight (weight percent). When the output from the chemical sensor 104 is 5 volts, the concentration of precursor vapor in the carrier gas is 1% by weight. In a typical embodiment, the chemical sensor 104 is a commercially available PIEZOCON from Rolex Industries.^{(Registered trademark)}).

0060In a typical embodiment, when the solid precursor compound is trimethylindium, the flow through delivery device 102 is controlled to provide delivery system 100 with a dew point of 17 ° C for trimethylindium vapor. As the chemical sensor 104 is used. The transport line between the delivery device 102 and the mass flow controller 208 (ie, the line transporting the carrier gas and precursor vapor) that feeds the reactor 200 is generally maintained at room temperature of 20 ° C. A dew point of 17 ° C is selected for trimethylindium to prevent trimethylindium vapor from condensing in the transport line. This 3 ° C difference allows for a continuous steady flow of precursor vapor to the reactor.

0061The pressure sensor 106 measures the pressure applied to the delivery device 102. The pressure sensor 106 can be a pressure gauge, a manometer, or the like. In combination with the second controller 110, the pressure sensor 106 and the second proportional valve 114 provide a mechanism to control the pressure of the precursor vapor and carrier gas.

0062The optional mixing chamber 107 is detailed in FIGS. 5 and 6. FIG. 5 shows the mixing chamber 107 when the opposing flows are included, while FIG. 6 shows the mixing chamber 107 which does not include the opposing flows.

0063FIG. 5 depicts a mixing chamber 107 with opposing flows for the first flow 202 and the second flow 204. The mixing chamber 107 includes a chamber 300 made of nickel alloy or stainless steel. The chamber 300 can have any shape, but is preferably cylindrical with equal or nearly equal diameter and height. In certain embodiments, it is desirable to have a mixing chamber diameter of at least 1 inch, specifically at least 2 inches, and more specifically at least 3 inches. In another embodiment, the height of the cylinder is 2 inches or more, specifically 3 inches or more, and more specifically 4 inches or more.

0064The first flow 202 enters the chamber 300 via the conduit 302, while the second flow 204 enters the chamber 300 via the conduit 304. The third stream 206 exits chamber 300 via conduit 306. The location of the mixing chamber 107 allows it to be part of a first closed loop and a second closed loop when it is used in a delivery system.

0065Each conduit preferably has a circular cross section with a diameter of 0.25 inch or greater, specifically 0.35 inch or greater, and more specifically 0.5 inch or greater. As can be seen in FIG. 5, the vessels 302 and 304 face each other. The outlets of the conduits are opposed to each other and less than 0.5 inches apart from each other so that the first flow 202 and the second flow 204 can be closely mixed with each other before leaving the chamber as the third flow 206 from the conduit 306. Designed to be. The conduit 306 is provided with a device 308 for connecting the chamber 300 to the conduit communicating with the inlet (not shown) to the reactor 200.

0066The conduit 302 is fitted with a flange 310, which is parallel to the plane of the chamber 300 communicating with the conduit 304. The flange 310 closely mixes the first flow 202 and the second flow with each other in the space 312 between the flange 310 and the surface of the chamber 300.

0067FIG. 6 shows a mixing chamber 107 having flows for a first flow 202 and a second flow 204 that are not opposed to each other. In this depiction, the first flow 202 enters the chamber 300 via the conduit 302, while the second flow 204 enters the chamber 300 via the conduit 304. The confluence of the two streams in chamber 300 results in a mixture between the two streams 202 and 204, which then exits chamber 300 via conduit 306 as a third stream 206. In the embodiments shown in FIGS. 5 and 6, conduits 302, 304 and 306 include nozzles, porous filters or other devices used to increase the mixing of the first flow 202 and the second flow 204. Can include. This mixing chamber contains filling materials such as beads, rods, tubes, horseshoe-shaped, rings, saddles, discs, saucers, or other suitable shapes such as needles, crosses, and spirals (coils and spirals). You can go out. If desired, a combination of the various filling materials described above may be used. The mixing chamber 107 may be used in any of the embodiments shown in FIGS. 2-4 below, where the first flow 202 contacts the second flow 204.

0068With reference to FIG. 1 again, the first controller 108 and the second controller 110 are built-in proportionals designed to provide optimized control of the total pressure or flow of carrier gas through the delivery system 100-. Integral-Differential (PID) control module. The input to the first proportional valve 112 is obtained from the pressure sensor 106. The input to the second proportional valve 114 is obtained from the chemical sensor 104. Each pressure / flow control system contains three basic components, in particular a pressure sensor, a proportional-integral-differential controller and a control element.

0069In the operation of the first proportional valve 112, the chemical sensor 104 measures the process pressure or carrier gas flow rate. The proportional-integral-differential controller compares the measured precursor concentration to the desired set point and adjusts the proportional valve 112 as needed to achieve the desired precursor vapor concentration in the third stream 206. To do.

0070In the operation of the second proportional valve 114, the pressure sensor 106 controls the detour flow to maintain the programmed pressure. The precursor steam requirement for reactor 200 is made by the mass flow controller 208. In response, the pressure sensor 106, in cooperation with the flow controller 110 and the second proportional valve 114, regulates the flow of carrier gas in the second flow 204 to achieve the desired pressure in the third flow 206. provide.

0071In some embodiments, multiple pressure / flow controllers may be dependent on the master pressure / flow controller, which allows the chemical sensor 104 and associated controller 108 to provide the desired gas ratio / mixture. While maintaining, the overall flow of carrier gas is adjusted to achieve the desired pressure. For example, the first proportional valve 112 and the second proportional valve 114 from FIG. 1 are shown as main pressure controllers (shown) to divide the total flow of carrier gas into a first flow 202 and a second flow 204. May be subordinate to (not). There will be no dynamic control of this concentration in this embodiment.

0072Shut-off valves 116 and 118, as well as inlet and outlet valves 120, 122 can be gate valves, ball valves, butterfly valves, needle valves and the like.

0073In one embodiment, in one method utilizing the delivery system 100 of FIG. 1, the reactor 200 draws vapor from the delivery device 102. The carrier gas may be delivered by either or both of the first proportional valve 112 and the second proportional valve 114, depending on the information provided by the chemical sensor 104 and the pressure sensor 106.

0074In certain embodiments, as the carrier gas travels through a fluid line (eg, a pipe or tubing) that includes a first stream 202 and a second stream 204, the carrier gas is generally at a temperature below the melting point of the solid precursor compound. Is heated to. The carrier gas in the first stream 202 travels through the delivery device 102 and is accompanied by a vapor of the precursor compound. The carrier gas with the accompanying steam then meets the carrier gas in the second stream 204. By adjusting the mass flow rate of the carrier gas in the first flow 202 and the second flow 204, the concentration of the precursor vapor can be maintained at a desired amount.

0075The "desired amount" is determined by the settings of the chemical sensor 104 and the pressure sensor 106 and the pressure / flow controller 108 and 110, respectively. The concentration of precursor vapor in the third stream 206 is measured by the chemical sensor 104. The pressure and / or flow rate of the carrier gas (with the precursor vapor associated therein) is measured by the pressure sensor 106.

0076If the concentration of precursor vapor relative to the carrier gas deviates from the desired amount or range, the chemical sensor 104 contacts the controller 108 and the proportional valve 112 to regulate the flow of the carrier gas to the delivery device 102. .. By adjusting the proportional valve 112, the amount of precursor vapor in the carrier gas in the flow 206 can be adjusted to be substantially constant. The flow rate of the carrier gas with the accompanying precursor vapor in the third flow 206 varies according to the request of the mass flow controller 208 and is controlled by the second controller 110 and the second proportional valve 114.

0077For example, if the concentration of precursor vapor to the carrier gas decreases in the third flow 206, electrical communication from the chemical sensor 104 to the controller 108 and the first proportional valve 112 includes the valve 116 and the inlet valve 120. Increase the flow of carrier gas through the first flow 202. This increases the amount of precursor vapor in the carrier gas in the first stream 202. The mass flow rate of the carrier gas in the second flow 204 is reduced by the amount of flow increase in the first flow 202. An increase in the amount of precursor vapor in the first stream 202, when combined with a reduced mass flow rate in the second stream 204, results in a regulation in the flow rate of the first stream 202. Produces a third flow 206 having a concentration of precursor vapor that is substantially constant relative to the amount of.

0078In another embodiment, if the concentration of precursor vapor increases in the third flow 206, electrical communication from the chemical sensor 104 to the controller 108 and the proportional valve 112 is carried through the first flow 202. Reduces gas flow. This leads to an increase in the amount of carrier gas flow in the second flow 204. The increase in the amount of carrier gas in the second stream 204, when combined with the reduced mass flow rate in the first stream 202, results in a regulation in the flow rate of the second stream 204 of the precursor vapor before the reduction. It produces a third stream 206 with a concentration of precursor vapor that is substantially constant relative to the amount.

0079Thus, the readings from the chemical sensor 104 and the pressure sensor 106 are used to regulate or maintain the precursor vapor concentration and the flow rate of the precursor vapor to the reactor 200.

0080As mentioned above, the delivery system 100 described herein is in carrier gas where it uses a first flow 202 (ie, source flow) and a second flow 204 (ie, detour flow). It is advantageous in lowering the dew point of the precursor vapor below the ambient temperature, or more specifically below the temperature of the connecting piping and hardware carrying the third flow 206.

0081FIG. 2 depicts another embodiment of the delivery system 100, where the carrier gas flows through the first flow 202 (which flows through the solid precursor compound) and the second flow 204 (which flows through the solid precursor compound). Divided into (bypass) and rejoined to form a third stream 206, in which the dew point is below ambient temperature. The flow direction of the first flow 202, the flow direction of the second flow 204, and the flow direction of the third flow 206 are unidirectional and do not face each other. As mentioned above, there are no opposing flows in the delivery system, except when a mixing chamber is used. This is because the use of opposed flows in this delivery system does not produce the desired mixture between the carrier gas and the precursor vapor, which results in the precursor vapor being delivered in the delivery. It results in non-uniform distribution to multiple reactors.

0082In FIG. 2, the delivery system 100 is similar to the delivery system of FIG. 1 except for the positions of the second proportional valve 114 and the needle valve 119. In this figure, a single proportional valve 114 operated by a controller 110 connected to the pressure sensor 106 is used to control pressure throughout the delivery system 100. The delivery system 100 of FIG. 2 includes at least two closed loops to regulate the pressure and the concentration of precursor vapor in the carrier gas.

0083As can be shown in FIG. 2, the first proportional valve 112 is located downstream of the second proportional valve 114 and may optionally be subordinate to the second proportional valve 114. The needle valve 119 is located downstream of the shut-off valve 118. Needle valve 119 facilitates an adjustable drop in pressure that can be used to regulate the flow of carrier gas through the first proportional valve 112 and delivery device 102.

0084FIG. 3 shows another embodiment of the delivery system 100 that includes a plurality of pressure regulators communicating with the delivery device 102. The pressure regulator functions to facilitate a drop in the pressure of the incoming carrier gas up to the pressure level used for the mass flow controller 208.

0085In this embodiment, the delivery system 100 includes a first pressure regulator 96 and a second pressure regulator 98 located downstream of the first pressure regulator 96. The first pressure regulator 96 sets the pressure of the incoming carrier gas to the first pressure P.₁From the second pressure P₂The second pressure regulator 98 makes it easier to drop to the second pressure P.₂From the third pressure P₃Facilitates further reduction of pressure on. First pressure P₁Is the second pressure P₂That is all, and the second pressure P₂Is the third pressure P₃That is all.

0086In some embodiments, a second pressure P₂Is the first pressure P₁50% to 70% of, specifically the first pressure P₁It is 55% to 65% of. In a typical embodiment, the second pressure P₂Is the first pressure P₁It is 58% to 62% of. Third pressure P₃Is the first pressure P₁40% to 48% of, specifically the first pressure P₁It is 43% to 47% of.

0087First pressure P₁Is 1,900 to 2,100 torr (250 to 280 kPa), specifically 1,950 to 2,050 torr (260 to 275 kPa). Second pressure P₂Is 950 torr to 1,400 torr (125 to 190 kPa), specifically 1,000 torr to 1,300 torr (130 to 175 kPa). Third pressure P₃Is 500 to 950 torr (65 to 125 kPa), specifically 850 torr to 925 torr (110 to 120 kPa). Therefore, the delivery device 102 is connected to the reactor 200 having an inlet pressure of 500 to 2,000 torr (65 to 260 kPa), specifically 700 to 1800 torr (90 to 240 kPa), and more specifically 900 torr (120 kPa). Can work. If desired, the reactor 200 operates in the range of 50 to 760 torr (6 to 101 kPa), thus removing precursor vapor from the delivery device 100 via the mass flow controller 208.

0088A first proportional valve 112, a shut-off valve 116, an inlet valve 120, a delivery device 102, an outlet valve 122 and a chemical sensor 104 are located downstream of the first pressure regulator 96. The first proportional valve 112 is located downstream of the first pressure regulator 96 and upstream of the second pressure regulator 98.

0089The first pressure regulator 96 communicates fluidly with the first proportional valve 112, shut-off valve 116, inlet valve 120, delivery device 102, outlet valve 122 and chemical sensor 104. The fluid flow including the first pressure regulator 96, the first proportional valve 112, the shutoff valve 116, the inlet valve 120, the delivery device 102, the outlet valve 122 and the chemical sensor 104 is referred to as the first flow 202. The first flow 202 directs the carrier gas to the inlet port of the delivery device 102.

0090The chemical sensor 104 is in contact with the first proportional valve 112. In one embodiment, the chemical sensor 104 is in electrical contact with the first proportional valve 112. The proportional valve 112, shut-off valve 116, inlet valve 120, delivery device 102, outlet valve 122 and chemical sensor 104 are in a closed loop.

0091The second pressure regulator 98 is located upstream of the shut-off valve 118 and the coil 211 of the pipe. The coil 212 of the pipe heats the carrier gas to the temperature inside the heated housing 103. The fluid flow including the second regulator 98, the second valve 118 and the coil 212 of the pipe is referred to as the second fluid 204.

0092The first flow 202 contacts the second flow 204 to form the third flow 206. In certain embodiments, the first flow 202 contacts the second flow 204 downstream of the outlet valve 122 of the delivery device 102. The chemical sensor 104 is located downstream of the outlet valve 122. The output signal from the chemical sensor 104 is directed to the first proportional valve 112 via the first controller 108.

0093In certain embodiments, the heating jacket 103 (shown in FIG. 3) has valves 116 and 118, a heater 212, substantially all first streams 202, substantially all second streams 204 and substantially all second streams 204. Includes all third flow 206. This arrangement maintains the temperature of the gas stream (ie, carrier gas and precursor vapor) above 20 ° C at all points in system 100, with a first stream 202, a second stream 204 and a third. Allows to prevent the condensation of vapor precursors in the flow 206. This allows uniform delivery of precursor vapor to or to multiple reactors. This arrangement is in other comparatively commercially available reactors where the precursor vapor often condenses on the inner wall of the pipe, leading to non-uniform delivery and distribution of the precursor to the reactor. Overcome the shortcomings you encounter.

0094In one method of operating the delivery system 100 of FIG. 3, the reactor 200 removes a mixture of precursor vapor and carrier gas from the delivery device 102. The chemical sensor 104 measures the precursor vapor concentration and / or flow rate (or pressure) in the third stream 206. If the precursor vapor concentration and / or flow rate in the third stream 206 is outside the desired limit, the sensor 104 communicates with the first proportional valve 112 via the first controller 108. The first controller 108 increases or decreases the voltage to the first proportional valve 112. By closing or opening the proportional valve 112, the concentration of precursor vapor in the carrier gas or the flow rate (or pressure) of the carrier gas can be adjusted to the desired value.

0095FIG. 4 shows another embodiment of the delivery system 100 of FIG. In this embodiment, the first proportional valve 112 is located downstream of the delivery device 102 instead of upstream as shown in FIG. The system also includes pressure regulators 96 and 98 that function to help reduce the pressure of the incoming carrier gas to the pressure level used by the mass flow controller 208 to supply the reactor 200. ..

0096Referring to FIG. 4, it is found that the shut-off valve 116, inlet valve 120, delivery device 102, outlet valve 122, first proportional valve 112 and chemical sensor 104 are located downstream of the first pressure regulator 96. Can be done. Thus, the first proportional valve 112 is located downstream of the first pressure regulator 96, but upstream of the point where the first flow 202 contacts the second flow 204. The first flow 202 thus includes a shut-off valve 116, an inlet valve 120, a delivery device 102, an outlet valve 122 and a first proportional valve 112. The first flow 202 directs the carrier gas to the inlet port of the delivery device 102.

0097The second flow 204 includes a second valve 118 and a coil 212 of the pipe.

0098The first flow 202 contacts the second flow 204 to form the third flow 206. In one embodiment, downstream of the first proportional valve 112, the first flow 202 contacts the second flow 204. The chemical sensor 104 is located downstream of the first proportional valve 112. The output signal from the chemical sensor 104 is directed to the first proportional valve 112 via the first pressure / flow controller 108. The chemical sensor 104 is in electrical contact with the first proportional valve 112.

0099The placement of the first proportional valve downstream of the delivery device 102 is advantageous in some examples to suppress concentration oscillations that may occur under a particular flow through the delivery system 100. Since the pressure at the delivery device 100 is higher in this embodiment, the flow through the delivery device 100 is usually higher to obtain the same concentration.

0100In one method of manufacturing the delivery system 100, the proportional valves 112 and / or 114 are located upstream of the delivery device 102. Shut-off valves 116 and / or 118 are located downstream of proportional valves 112 and / or 114, respectively, and upstream of delivery device 102. The delivery device 102 is arranged within the heated housing 103. The inlet valve 120 and the outlet valve 122 are arranged at the inlet and outlet of the delivery device 102, respectively. The chemical sensor 104 and the pressure sensor 106 are located downstream of the delivery device 102 and form a closed loop with the proportional valves 112 and / or 114, respectively. The delivery system 100 communicates with the reactor 200 via a mass flow controller 208. The mass flow controller 208 is located upstream of the reactor 200.

0101This delivery system 100 is advantageous in that it can deliver a constant flow of precursor vapor at a higher flow rate than other comparative devices. This method does not involve opposing flows. The flow through the entire delivery system 100 involves a flow in a single direction. This results in a better mixture of carrier gas and precursor vapor and prevents the formation of holes in the solid precursor. Systems with opposing flows suffer from problems that occur when the pressure in one of the flows increases more than in the other. This results in a non-uniform supply of precursor vapor to the reactor. It also causes non-uniform sublimation of the solid precursor, leading to holes in the solid precursor, which in turn results in a non-uniform supply of precursor vapor to the reactor.

0102The system 100 also allows delivery of uniform concentrations of precursor to reactor 200. This feature distinguishes this system 100 from other comparative delivery systems that supply a constant number of moles per unit time. Delivery of a constant number of moles per unit time is not always converted to a constant number of moles per unit volume, especially if the system has opposing flows of carrier gas. This often results in variations in precursor per unit volume of carrier gas delivered to the reactor, which results in the production of non-uniform products.

0103This disclosed system 100 also allows a uniform mass flow rate of the precursor to the reactor over an extended period of time.

0104In certain embodiments, the delivery system 100 is 1 standard liter / minute (slm) or higher, specifically 2 standard liters / minute (slm) or higher, and more specifically 3 standard liters / minute (slm) or higher. At a temperature of 60 ° C or higher, at a pressure of 900 torr (120 kPa) or higher, 1,500 micromol / min or higher, specifically 1,750 micromol / min or higher, more specifically, while maintaining the carrier gas flow rate to the reactor 200. The precursor vapor can be delivered at a rate of 2,000 micromol / min or more.

010596 First pressure regulator 98 Second pressure regulator 100 delivery system 102 Delivery device 103 heating jacket 104 chemical sensor 106 pressure sensor 107 Mixing chamber 108 First pressure / flow controller 110 Second pressure / flow controller 112 1st proportional valve 114 Second proportional valve 116, 118, 120, 122 Shut-off valve 200 reactor 202 First flow of carrier gas 204 Second flow of carrier gas 206 Third flow 208 Mass Flow Controller 212 Piping coil 300 chambers 302, 304, 306 conduits 310 flange 312 space