Productivity enhancing thermal sprayed yttria-containing coating for plasma reactor

Increased throughput of plasma reactors for thermal spraying of yttria-containing coatings

Technical field

The invention relates to a component of a semiconductor material processing equipment, the component being formed of a material that can reduce contamination of the semiconductor material during the processing of the semiconductor material. The invention also relates to a method of manufacturing the assembly.

Background technique

In the field of semiconductor material processing, vacuum processing chambers are used for etching and chemical vapor deposition (CVD) of materials on substrates. The production gas flows into the processing chamber while a radio frequency (RF) field is applied to the production gas to generate a production gas plasma. The plasma performs the required etching or deposition of the selected material on the wafer. Examples of parallel plates, variable pressure coupled plasma (TCPTM), also known as inductively coupled plasma (ICP), and electron-cyclotron resonance source (ECR) reactors and their components are disclosed in commonly owned U.S. Patent No. 4,340,462 No. 4,948,458, No. 5,200,232 and No. 5,820,723.

As disclosed in, for example, US Patent Nos. 5,262,029 and 5,838,529, during semiconductor substrate processing, the substrate is generally supported in a vacuum chamber by a substrate holder. Various gas supply systems can be used to supply production gas to the chamber.

In addition to plasma chamber equipment, other equipment used to process semiconductor substrates include: transfer mechanisms, gaskets, lifting mechanisms, load locks, door mechanisms, robotic arms, fasteners, and so on.

Plasma is used to remove material by etching or deposition on the substrate. The conditions of the plasma etching cause significant ion bombardment of the surface of the processing chamber exposed to the plasma. This ion bombardment, combined with plasma chemistry and/or etching byproducts, can cause significant erosion, corrosion, and corrosion-erosion of the plasma exposed surfaces of the processing chamber. As a result, the surface material is removed by physical and/or chemical damage, including erosion, corrosion and/corrosion-erosion. This damage causes the following problems: including short part life, increased consumption costs, particulate contamination, transition metal contamination on the wafer, and process drift.

According to these problems, plasma processing chambers have been designed to include parts such as disks, rings, and cylinders, which confine the plasma to the wafer to be processed. However, these parts are constantly being eroded by the plasma, and therefore eventually erodes or accumulates the polymer structure. Eventually, these parts suffer from this loss and make them no longer usable. These parts with a relatively short life are generally referred to as "consumables." If the life of the consumable parts is short, the cost to the owner is high. The erosion of consumables and other parts causes contamination of the plasma processing chamber.

Because of the corrosive and corrosive properties of the plasma environment in the reactor, and the need to minimize particle and/or metal contamination, it is desirable that the components of the equipment (including consumables and other parts) have appropriately high corrosion resistance and Corrosion resistance. Parts have been formed of materials that provide corrosion resistance and erosion resistance in a plasma environment. See, for example, U.S. Patent Nos. 5,798,016, 5,911,852, 6,123,791, and 6,352,611.

Summary of the invention

The present invention provides components of semiconductor processing equipment, which are made of materials that can provide improved wear resistance to physical and/or chemical attack in a plasma processing environment. These components provide low levels of pollution compared to metals and particulates.

According to the present invention, an exemplary embodiment of a semiconductor processing equipment assembly includes a substrate including a surface and a thermally sprayed yttrium oxide-containing coating on the surface. The coating contains the outermost surface of the component.

An exemplary embodiment of a method of manufacturing a semiconductor processing equipment assembly according to the present invention includes forming a yttria-containing coating on a surface of the assembly by thermal spraying. The coating contains the outermost surface of the component.

In a preferred embodiment, the thermal spray coating containing yttrium oxide can be directly formed on the surface of the substrate.

In addition, the present invention provides semiconductor processing equipment including at least one of the above-mentioned yttrium oxide-containing components.

Description of the drawings

Through the following detailed description, in conjunction with the accompanying drawings, it is not difficult to understand the present invention.

Figure 1 illustrates a conventional plasma spraying method.

Figure 2 shows a cross-sectional view of a vapor ring used in a plasma etching apparatus according to an exemplary embodiment of the present invention.

Figure 3 shows an etching chamber containing an exemplary embodiment of a component according to the invention.

Figure 4 shows another etching chamber containing an exemplary embodiment of a component according to the invention.

Figure 5 shows an exemplary embodiment of a protective coating according to the present invention.

Fig. 6 shows another exemplary embodiment of a protective coating according to the present invention.

Figure 7 shows the contamination levels of oxide wafers and bare silicon wafers coated and uncoated with a yttria-containing coating according to the present invention.

detailed description

The present invention provides components suitable for semiconductor material processing equipment. These components can provide resistance to wear with respect to the physical and chemical destruction of plasma generated in semiconductor material processing equipment during processing. As used herein, the term "wear resistance" includes, but is not limited to, corrosion resistance, corrosion resistance, and/or corrosion-erosion resistance.

The component contains a coating containing yttrium oxide. The yttrium oxide-containing coating provides an exterior surface that is resistant to the physical and chemical damage of plasma in semiconductor processing equipment.

In addition, the present invention provides a method of manufacturing a component that includes a coating containing yttrium oxide to improve the wear resistance of the component in a plasma environment.

Those skilled in the art should understand that anti-loss materials can be applied to different processing equipment for processing different semiconductor materials. In addition, the anti-loss material can be applied to different components of the processing equipment. The exemplary components include (but are not limited to) parts of a plasma and/or vacuum chamber, such as, for example, chamber walls, substrate supports, gas distribution systems (including showerheads, baffles, rings, nozzles) Etc.), fasteners, heating units, plasma screens, gaskets, transmission module components (such as robotic arms, fasteners, inner and outer chamber walls, etc.).

The yttrium oxide-containing material preferably consists essentially of yttrium oxide. In an attempt to minimize contamination of semiconductor materials processed in equipment incorporating one or more components containing yttria-containing materials, it is desirable that the yttria-containing materials be as pure as possible, for example, including the smallest amount of potentially contaminating units , Such as transition metals, alkali metals and so on. For example, yttrium oxide-containing coatings can be pure enough to avoid contamination on wafers of 1010 atoms/cm2 or higher, preferably 105 atoms/cm2 or higher. Preferably, the yttria-containing material has a high purity of at least about 99%, and more preferably from about 99.95% to about 100%.

The yttria-containing coating can provide high bonding strength to the underlying substrate. Preferably, the yttria-containing coating has an adhesive tensile strength of from about 2000 psi to about 7000 psi.

The yttrium oxide-containing coating can provide a low degree of porosity, which is beneficial to minimize the contact of the aggressive atmosphere with the underlying substrate, and thus subsequently minimize the corrosion, erosion and/or corrosion of the substrate caused by the aggressive atmosphere Corrosion-physical and/or chemical damage caused by erosion. Preferably, the yttria-containing coating has a porosity of less than 15% by volume, more preferably less than about 3% by volume, and most preferably less than 1% by volume.

In addition, the yttria-containing coating can provide a high hardness to resist corrosion. Preferably, the ceramic material has a hardness (HVO3) from about 200 to about 800.

The yttria-containing coating has a crystal structure, which is preferably from about 10% to about 100% cubic, and more preferably greater than about 95% cubic.

The yttrium oxide-containing coating may have a color ranging from pure white to dark gray/black. The coatings are preferably white.

The yttrium oxide-containing coating can provide the desired anti-loss characteristics used in semiconductor processing equipment such as plasma etching chambers. In particular, the yttria-containing coating provides a surface that can reduce ion-induced erosion and related levels of particulate contamination in the plasma reactor chamber. The yttrium oxide-containing coating can protect the underlying substrate from physical damage and chemical damage by the plasma.

The anti-loss coating can be used for etching, deposition and other applications in various plasma atmospheres. General etching chemicals include: for example, chlorine-containing gases, including (but not limited to) Cl2, HCl, and BCl3; bromine-containing gases, including (but not limited to) Br2 and HBr; oxygen-containing gases, including (but not limited to) O2, H2O and SO2; fluorine-containing gases, including (but not limited to) CF4, CH2F2, NF3, CH3F, C2F6, CHF3, and SF6; and inert gases and other gases, including (but not limited to) He, Ar, and N2. These and other gases can be used in any appropriate combination according to the desired plasma. The general maximum flow rate of etching chemicals is: Cl2, 200sccm; HCl, 100sccm; BCl3, 200sccm; HBr, 200sccm; O2, 20sccm; H2O, 100 sccm; SO2, 200sccm; CF4, 200sccm; CH2F2, 100sccm; CH3F, 100sccm; C2F6, 100sccm; CHF3, 100sccm; SF6, 200sccm; He, 200sccm; Ar, 200sccm and N2,200sccm. The appropriate flow rate of different production gases can be selected based on the following factors: including (but not limited to) the type of plasma reactor, power setting, chamber pressure, plasma dissociation rate, etching chemistry, material being etched and in use Special step of etching process of production gas.

The etching operation conditions of an exemplary plasma etching reactor of a high-density plasma reactor are as follows: the substrate temperature is from about 0°C to about 70°C; the chamber pressure is from about 0 mtorr to about 100 mtorr; the gas flow rate is from about 10 sccm And the plasma generation power supply is from more than 0 watts to about 1500 watts, and generally from about 200 watts to about 800 watts. The most appropriate power source depends on the type of wafer etched in the plasma reactor.

The component including the yttrium oxide-containing coating can be used in an etching chamber of a semiconductor processing equipment for etching silicon-containing and metal-containing materials in a semiconductor plasma etching process. For example, the silicon-containing materials that can be etched in the etching chamber include (but are not limited to): single crystal silicon, polycrystalline silicon, amorphous silicon, silicon nitride, silicon oxynitride, silicide, silicon dioxide, low-k materials, and High-k material. The silicon-containing materials may be doped or undoped and/or annealed or unannealed.

Materials containing conductive or semi-conductive metals that can be etched include (but are not limited to): aluminum, aluminum alloy, tungsten, tungsten alloy, titanium, titanium alloy, tantalum, tantalum alloy, platinum, platinum alloy, ruthenium, ruthenium alloy, chromium, Chromium alloys, iron, iron alloys, nickel, nickel alloys, cobalt, cobalt alloys, molybdenum, molybdenum alloys, silicides of titanium, tungsten, chromium, cobalt and/or molybdenum, ferroelectric materials such as platinum silicide and ruthenium oxide, and for example GMR material of tantalum nitride, chromium silicide and NiFeCo alloy.

Preferably, the yttria-containing coating is formed on a substrate by thermal spraying technology. In thermal spray technology, ceramic powder is melted and incorporated into an air flow directed toward the component being sprayed. One advantage of the thermal spray technique is that the components are only coated on the side facing the thermal spray gun, and masking can be used to protect other areas. Conventional thermal spraying techniques, including plasma spraying, are described in Pawlowski's The Science and Engineering of Thermal Spray Coating (John Wiley, 1995). This description is fully incorporated herein by reference. The thermal sprayed yttrium oxide-containing coating may be formed on any substrate that is suitably shaped so that it can be coated.

A particularly preferred thermal spraying technique is plasma spraying. Plasma spraying can coat the complex interior surfaces of the chamber and other chamber components. Figure 1 illustrates a general plasma spraying method. The coating material, usually in the form of powder 112, is usually injected into the high temperature plasma flame 114 via the external powder port 132. The powder is rapidly heated and accelerated to a high speed. The hot material impacts the substrate surface 116 and rapidly cools to form a coating 118.

The plasma spray gun 120 includes an anode 122 and a cathode 124, both of which are water-cooled. The plasma gas 126 (eg, argon, nitrogen, hydrogen, helium) generally flows around the cathode in the direction indicated by arrow 128 and passes through an anode constriction nozzle. The plasma is initiated by a high-voltage discharge, which can cause local ionization and the formation of a DC arc in the conductive path between the cathode 124 and the anode 122. Resistance heating from the arc causes the gas to form a plasma. The plasma leaves the anode nozzle part in a free or neutral plasma flame (ie, plasma without current). When the plasma is stable and ready to spray, the arc extends below the nozzle. The powder 112 is rapidly heated and accelerated so that the spraying distance 136 between the nozzle end and the substrate surface can be about 125 to 150 mm. The plasma sprayed coating is produced by impacting the surface 116 of the substrate with particles that are melted or softened by heating.

The thermal spray coating containing yttrium oxide can be directly formed on the preferred substrate material, with or without first treating the substrate surface to improve the adhesion of the coating, and/or with or without first forming an intermediate layer on the substrate Coating to enhance the adhesion of the coating on the substrate. For example, in the case of an untreated substrate surface or using an intermediate coating, the yttria-containing coating can be directly applied to an anodized aluminum, alumina, or quartz substrate. In a preferred embodiment, the yttrium oxide-containing coating provides suitable adhesion to the substrate without processing the substrate and/or forming an intermediate layer. Therefore, because the yttria-containing coating can be applied to the substrate without performing the additional existing processing steps, the increased cost of the coating method caused by the additional processing steps can be avoided , Complexity, and/or completion time.

Before forming the yttrium oxide-containing coating on the substrate, the surface of the substrate to be coated is preferably cleaned to remove unnecessary surface substances such as oxides or oils. In some embodiments, surface treatment techniques such as cleaning and particle blasting can be used to provide a more chemically and physically active surface for coating bonding. It is less preferred that any suitable method (such as sandblasting) can roughen the substrate surface before coating. The roughening of the substrate increases the surface area of the coating bonding, which increases the bonding strength of the coating. The rough substrate surface profile can also promote mechanical keying or interlocking of the coating and the substrate.

For aluminum reactor components, before coating, the surface of the component to be coated is preferably anodized, but the anodized surface is not roughened. The anodized layer provides an additional barrier (ie, in addition to the protection provided by the coating) to prevent corrosion damage of the aluminum material below. The anodized aluminum layer formed on an aluminum substrate (such as 6061-T6 aluminum) may have any suitable thickness. For example, the thickness of the anodized aluminum layer is generally from about 2 mils to about 10 mils. The surface of the anodized aluminum layer can be polished as appropriate. For example, the surface finish may have a surface roughness of about 20 microinches to about 100 microinches. The anodized layer can be sealed using any suitable technique, such as by using boiling deionized water.

The thermal spray coating containing yttrium oxide can have the required surface roughness characteristics, which can effectively promote the adhesion of contaminants to the coating. Such contamination may include polymer deposits, which are produced by the use of polymers that form species (usually fluorocarbons) during plasma etching processes (such as metal etching processes). As described in co-pending U.S. Patent Application No. 09/749,917, which is fully incorporated herein by reference, the polymer deposits can peel off or peel the surface of the chamber during the etching process and contaminate the substrate in the chamber . This problem is exacerbated by thermal cycles that occur during repeated plasma treatment cycles.

The thermally sprayed yttrium oxide-containing coating may have a surface roughness coefficient (Ra), which is suitable for enhancing the adhesion of polymer by-products generated during substrate processing in a plasma reactor. For example, the arithmetic average surface roughness (Ra) of the thermally sprayed yttrium oxide-containing coating may range from about 5 microinches to about 400 microinches, and preferably from about 120 microinches to about 250 microinches. The surface roughness coefficient in this range promotes the adhesion of the polymer deposited on the surface of the reaction chamber during the plasma etching process (for example, metal etching). Therefore, the thermally sprayed yttrium oxide-containing coating can improve the adhesion of the polymer deposits on the component, and thus reduce the occurrence of pollution caused by the polymer deposits.

However, in some preferred embodiments, the thermally sprayed yttria-containing coating may be smooth. For example, in a silicon etching process, significant deposits tend to form on the surface of the chamber. For these methods, it is not desirable that the thermally sprayed yttrium oxide-containing coatings have a rough surface to promote adhesion of the deposits on the coatings. In addition, the smoother surface is relatively easy to clean.

In some preferred embodiments, the components including yttria-containing coatings are used in high-density plasma reactors. An exemplary reactor of this type is the TCP 9400TM plasma etching reactor, which is commercially available from Lam Research, Fremont, California. In the TCP9400TM reactor, the processing gas (for example, Cl2, HBr, CF4, CH2F2, O2, N2, Ar, SF6, and NF3) is introduced into the vapor ring located at the bottom of the etching chamber, and then it is introduced into the reactor chamber through the vent in. Figure 2 shows a vapor ring used in a TCP 9400TM etching reactor. As shown in FIG. 2, the main body of the vapor ring 40 surrounds the substrate support 44. The bottom surface of the steam ring 40 contains an annular air guide groove 60. The aforementioned air hole 50 extends to the air guide groove 60.

The vapor ring 40 is generally composed of aluminum. The upper surface of the vapor ring is directly exposed to the plasma and therefore undergoes erosion, corrosion, and corrosion-erosion. To protect these surfaces, the vapor ring is usually covered with an aluminum oxide layer. For example, in silicon etching applications, fluorine-containing atmospheres can produce aluminum fluoride "brown dust" by attacking anodized aluminum. In metal etching applications, boron trichloride (BCl3) can erode the anodized surface and cause corrosion of the components. In addition, during use, the anodized aluminum is relatively brittle, and can be broken during repeated reactor thermal cycles. The cracks formed in the anodized layer can allow corrosive production gases to attack the underlying aluminum layer, thereby reducing part life and causing metal and particle contamination of processed substrates such as wafers, flat panel display substrates, and the like.

In an exemplary embodiment, a coating 42 containing yttria material may cover the exposed vapor ring surface. The coating may be formed on a bare (with or without a natural oxide surface film) aluminum substrate or an aluminum oxide layer (for example, aluminum with an anodized surface). When the vapor ring is coated, the coating can be allowed to partially penetrate into the pores to coat and protect the inner wall thereof, but does not block the opening. In addition, the pores may be uncoated, for example, the pores may be blocked or covered during the coating process.

Other components of the TCP 9400TM etching reactor that can be exposed to plasma during the process can also be coated with yttrium oxide coatings. These components include, for example: chamber walls, chamber gaskets, clamping devices, and dielectric windows relative to the substrate. A coating containing yttrium oxide is provided on the upper surface of a clamping device such as an electrostatic chuck, which provides additional protection to the chuck during cleaning cycles where there is no wafer, and therefore the upper surface of the chuck The surface is directly exposed to the plasma.

Another exemplary polysilicon etching reactor that may include a yttrium oxide-containing coating according to the present invention is the VersysTM polysilicon etcher or the 2300TM etcher, which can also be obtained from Lam, Fremont, California. Purchased by Research, as shown in Figure 3. The reactor includes a reactor chamber 150 that includes a substrate support 152 including an electrostatic chuck 154 that provides a clamping force for a substrate (not shown) mounted thereon. The focus ring 170 is mounted on the substrate support 152 around the electrostatic chuck 154. The substrate holder 152 can also be used to apply an RF bias to the substrate. The substrate can also be back-cooled using a heat transfer gas such as helium. In the 2300TM etcher, one or more of the process gas (e.g., Cl2, HBr, CF4, CH2F2, O2, N2, Ar, SF6, or NF3) is fed via a gas injector 168 located at the top of the chamber 150 and connected to the gas feed 156. Species) are introduced into the chamber 150. The gas injector 168 is usually made of quartz or a ceramic material such as alumina. As shown, the inductive coil 158 can be powered by a suitable RF source (not shown) to provide a high-density (for example, 1011-1012 ions/cm3) plasma. The inductive coil 158 couples RF energy into the chamber 150 via the dielectric window 160. The dielectric window 160 is usually made of quartz or alumina. The dielectric window 160 is shown as being mounted on the ring member 162. The ring member 162 separates the dielectric window 160 from the top end of the chamber 150, and is called a "gas distribution plate". The chamber liner 164 surrounds the substrate support 152. The chamber 150 may also include appropriate vacuum pumping equipment (not shown) to maintain the required pressure in the chamber.

In FIG. 3, selected inner surfaces of the following reactor components are shown in accordance with the present invention as being coated with yttrium oxide-containing coating 166: such as ring member 162, dielectric window 160, substrate support 152, chamber liner 164. Gas injector 168, focusing ring 170 and electrostatic chuck 154. As shown in FIG. 3, the selected inner surface of the chamber 150 and the substrate support 152 under the chamber liner 164 may also have an yttria-containing coating 166. Any or all of these surfaces and any other internal reactor surface may have a coating 166 containing yttria.

These components can be used in high-density oxide etching processes. One exemplary oxide etch reactor is the TCP 9100TM plasma etch reactor, which is commercially available from Lam Research, Fremont, California. In the TCP 9100TM reactor, the gas distribution plate is a circular plate directly below the TCPTM window, which is also a vacuum sealing surface at the top of the reactor in a plane that is higher than and parallel to the semiconductor wafer. The gas distribution plate is sealed to a gas distribution ring located around the gas distribution plate. The gas distribution ring feeds gas from a gas source into a volume defined by the following components: a gas distribution plate, an inner surface of a window below an antenna in the form of a hairspring coil that provides RF energy to the reactor, and a gas distribution ring . The gas distribution plate contains holes of nominal diameter extending through the plate. The spatial distribution of the holes through the gas distribution plate can be changed to optimize the etching homogeneity of the layers to be etched, such as the photoresist layer, the silicon dioxide layer and the underlying material on the wafer. The cross-sectional shape of the gas distribution plate can be changed to distribute the RF power to the plasma in the reactor. The gas distribution plate is an insulating material so that the RF power is coupled to the reactor through the gas distribution plate. In addition, it is desirable that the material of the gas distribution plate is highly resistant to chemical sputtering-etching in a plasma environment such as oxygen, halogen, or hydrofluorocarbon gas to avoid the consequent disconnection and synthesis of particles.

Figure 4 illustrates a plasma reactor of the aforementioned type. The reactor includes a reaction chamber 10. The substrate support 12 includes an electrostatic chuck 34 that provides clamping force and RF bias to a substrate 13. The substrate can also be back-cooled using a heat transfer gas such as helium. The focus ring 14 confines the plasma to a region above the substrate. Place an energy source for maintaining a high-density plasma in the chamber (for example, 1011-1012 ions/cm3) at the top of the reaction chamber 10, such as an antenna powered by a suitable RF source to provide high-density plasma 18. The reaction chamber includes a vacuum pump device for maintaining the interior of the chamber at a desired pressure (for example, less than 50 mtorr, usually 1-20 mtorr).

A substantially flat dielectric window 20 is provided inside the antenna 18 and the processing chamber 10, and it forms a vacuum wall at the top of the processing chamber 10. A gas distribution plate 22 is provided below the window 20, and it includes an opening for passing the production gas from the gas supply 23 to the chamber 10. A gasket 30 (such as a tapered or cylindrical gasket) extends from the gas distribution plate 22 and surrounds the substrate holder 12. The antenna 18 may have a groove 24 through which temperature control fluid flows via inlet and outlet ducts 25, 26. However, the antenna 18 and/or the window 20 do not need to be cooled, or may be cooled by other suitable techniques such as blowing in gas through the antenna and the window, transferring a cooling fluid, or communicating with the window and/or gas distribution plate. Thermal contact and so on.

In operation, a substrate such as a semiconductor wafer is positioned on the substrate holder 12 and fixed with an electrostatic chuck 34. However, other clamping members such as mechanical clamping members may also be used. In addition, helium back cooling can be used to improve the heat transfer between the substrate and the chuck. Then, the production gas is supplied to the vacuum processing chamber 10 by passing the production gas through the gap between the window 20 and the gas distribution plate 22. Suitable gas distribution plate configurations (ie, shower heads) are disclosed in commonly-owned US Patent Nos. 5,824,605, 6,048,798, and 5,863,376, which are all incorporated herein by reference. By supplying appropriate RF power to the antenna 18, a high-density plasma is generated in the space between the substrate and the window.

In FIG. 4, the exposed inner surfaces of the reactor components, such as the gas distribution plate 22, chamber liner 30, electrostatic chuck 34, and focus ring 14 are coated with a coating 32 containing yttrium oxide. However, only selected parts of these surfaces and/or other surfaces can be coated with yttria-containing coatings.

Those skilled in the art will understand that the above-mentioned high-density polysilicon and insulating etching chamber are just exemplary embodiments of plasma etching reactors that can be incorporated into the components. Components including yttria-containing coatings can be used in any etching reactor (eg, metal etching reactor) or other types of semiconductor processing equipment, where it is desired to reduce plasma-induced erosion, corrosion, and/or corrosion-erosion and Related pollution.

Other exemplary components that may have yttria-containing coatings include, but are not limited to, chamber walls, substrate holders, fasteners, and the like. These components are usually made of metal (e.g., aluminum) or ceramic (e.g., alumina), and are usually exposed to plasma, and often exhibit signs of erosion, corrosion, and/or corrosion-erosion. Other parts that can be coated with yttria-containing coatings do not need to be directly exposed to the plasma, but can be exposed to corrosive gases, such as those emitted from processed wafers or the like. Therefore, other equipment for processing semiconductor substrates may also have yttrium oxide-containing coatings. Such equipment may include conveying mechanisms, gas supply systems, liners, lifting mechanisms, load locks, door mechanisms, robotic arms, fasteners, and so on.

In a preferred embodiment, a yttria-containing coating is provided on a metal component. As described above, anodized and unanodized aluminum-based materials can be coated with yttria-containing coatings, including aluminum and aluminum alloys, such as 6061-T6 aluminum. Other exemplary metal materials that can be coated include, but are not limited to, stainless steel and refractory metals, such as 304 and 316 stainless steel. Because the yttrium oxide-containing coating forms an anti-wear coating on the component, the components below are protected to prevent direct exposure to plasma. Therefore, the metal components can be protected against plasma erosion, corrosion, and/or corrosion-erosion damage. As a result, a metal material such as an aluminum alloy can be used without considering the addition of alloys, the structure of particles, or surface conditions.

In addition, yttrium oxide coatings can be used to coat various ceramic or polymer materials. In particular, the reactor components can be made of the following ceramic materials: including (but not limited to) alumina (Al2O3), silicon carbide (SiC), silicon nitride (Si3N4), boron carbide (B4C) and/or boron nitride (BN). The coatable polymeric materials are preferably those that can withstand the high temperature conditions in the plasma reactor.

If necessary, one or more intermediate layer materials can be provided between the surface of the component to be coated and the yttrium oxide-containing coating. Figure 5 shows a coated component according to an exemplary preferred embodiment. A conventional technique is used to coat the first intermediate coating layer 80 on the substrate 70 as needed. The optional first intermediate coating layer 80 is thick enough to adhere to the substrate, and allows the second intermediate coating layer 90 or the yttria-containing coating layer 100 to be processed before forming an optional second intermediate coating layer 90 or the yttrium oxide-containing coating layer 100. The first intermediate coating layer 80 and the second intermediate coating layer 90 may have any suitable thickness that can provide these desired characteristics. These coatings may have a thickness of at least about 0.001 inches, preferably from about 0.001 to about 0.25 inches, more preferably from about 0.001 to about 0.15 inches, and most preferably from about 0.001 inches to about 0.05 inches.

After the optional first intermediate coating 80 is deposited on the reactor assembly 70, the first intermediate coating may be processed, such as by rough machining using any suitable technique, and then processed with an optional second intermediate coating. Layer 90 or yttria-containing coating 100 is applied. The roughened first intermediate coating 80 provides a particularly good bonding effect with subsequently applied coatings. It is desirable that the second intermediate coating 90 impart high mechanical compressive strength to the first intermediate coating 80 and reduce the formation of cracks in the second intermediate coating 90.

The second intermediate coating layer 90 is thick enough to adhere to the first intermediate coating layer 80 and allows it to be processed before any additional intermediate coating or outer yttria-containing coating 100 is formed. The second intermediate coating 90 may be processed by, for example, rough machining. The second intermediate coating 90 may have any suitable thickness that provides these desired characteristics, such as at least about 0.001 inches, preferably from about 0.001 to about 0.25 inches, more preferably from about 0.001 to about 0.15 inches, and most preferably from about A thickness of 0.001 inches to about 0.05 inches.

The first and second intermediate coatings can be made of any metal, ceramic, and polymer material suitable for use in a semiconductor plasma processing chamber. Particularly desirable metals that can be used include, but are not limited to, refractory metals that can withstand high processing temperatures. Preferred ceramics include (but are not limited to) Al2O3, SiC, Si3N4, B4C, AIN, TiO2 and mixtures thereof. Preferred polymers include, but are not limited to, fluoropolymers such as polytetrafluoroethylene and polyimide.

The intermediate coating can be applied by any suitable deposition technique, such as: electroplating (for example, electroless plating or electroplating), sputtering, dip coating, chemical vapor deposition, physical vapor deposition, electrophoretic deposition, thermal, etc. Static method, cold isostatic method, compression molding, casting, compression molding and sintering, and thermal spraying (for example, plasma spraying).

According to its required characteristics, the optional first intermediate coating 80 and the second intermediate coating 90 may have the same or different compositions from each other. If necessary, an additional intermediate coating layer such as a third, fourth or fifth intermediate coating layer of the same or different material can also be provided between the yttrium oxide-containing coating and the substrate.

Figure 6 shows another exemplary embodiment of a yttria-containing coating. In this embodiment, the yttrium oxide-containing coating 100 is directly placed on a substrate (that is, without any intermediate layer formed), which is the outer surface of the component 70. In this and other embodiments, the coating 100 may have any suitable thickness. When the yttrium oxide-containing coating layer is exposed to the plasma atmosphere, the yttrium oxide-containing coating layer 100 has at least the smallest thickness, which provides sufficient coating for the underlying surface to provide wear resistance and protect the underlying surface Prevent physical and chemical damage. In particular, the coating 100 may have a thickness in the following range: from about 0.001 inches to about 1 inch; preferably from about 0.001 inches to about 0.5 inches; more preferably from about 0.001 inches to about 0.1 inches; and most preferably from About 0.01 inches to about 0.1 inches. This thickness can also be used in other embodiments. The thickness of the yttria-containing coating can be selected to be compatible with the plasma environment that will be encountered in the reactor (e.g., etching, CVD, etc.).

The yttrium oxide-containing coating may be provided on all or part of the reaction chamber and components. In a preferred embodiment, the coating is provided on areas of the reactor chamber that are exposed to the plasma environment, such as those parts that are in direct contact with the plasma or parts that are located behind the chamber assembly (such as gaskets). In addition, it is preferable to provide the yttria-containing coating in the region of the reactor chamber that is subjected to relatively high bias voltage (ie, relatively high sputter ion energy).

Advantages are achieved by applying yttria-containing coatings. That is, the yttria-containing coating can be used for all plasma chemistries. The coating is beneficial for use in fluorine-containing and BCl3-containing atmospheres, which are highly corrosive to anodized aluminum. By using yttria-containing coatings in these atmospheres, significantly reduced erosion rates can be achieved in plasma reactors.

Tests were conducted to demonstrate the effectiveness of yttria-containing coatings in providing corrosion-resistant surfaces in a plasma environment. Three anodized 6061-T6 aluminum samples and three samples each made by forming a thermal spray coating containing yttrium oxide on the anodized 6061-T6 aluminum sample surface are attached to the plasma On the wall of the chamber in the bulk reactor. The yttrium oxide-containing coating has a composition of about 99.95% by weight of yttrium oxide. The samples each had a diameter of 1 inch and a thickness of 0.375 inches. The sample is attached to the wall of the chamber. The plasma was generated by a production gas containing Cl2 and BCl3 at the same flow rate, and the pressure inside the chamber was set to 6 mTorr. The bare silicon wafer is etched in the reactor chamber. The sample was tested for a total of about 90 RF-hours.

After the test, the yellow dust penetrated into the reactor chamber. The dust was analyzed using EDS analysis, and it was found that it mainly contained boron, oxygen, and chlorine.

An analytical balance is used to calculate the sample to determine the mass loss, and to calculate the sample to determine the expected erosion rate. The anodized 6061-T61 aluminum sample without the yttrium oxide coating was determined to have lost approximately 15 to 20 mg. Therefore, the production gas is highly corrosive relative to these uncoated samples.

In contrast, the three samples with coatings containing yttrium oxide increased the weight of each due to the accumulation of dust on the coatings. The weight gain of the three coated samples ranged from about 0.8 mg to about 1.2 mg. The weight increase rate of the three coated samples ranged from about 0.009 mg/RF-hr to about 0.013 mg/RF-hr.

As for the expected erosion rate, as evidenced by the significant weight reduction, the anodized 6061-T6 aluminum sample without the yttrium oxide coating was significantly corroded. These samples were determined to have a predicted average erosion rate from about 20 to 27 Å/RF-min. In contrast, the three samples with coatings containing yttria were not corroded.

In addition, because the aluminum component is protected from fluorine attack, when the coated component is used in the atmosphere of the fluorine-containing production gas in the plasma reactor, the yttrium oxide-containing coating can reduce the formation of aluminum fluoride. Minimize or even prevent its formation.

Tests were also carried out to show that by providing components in the plasma reactor chamber including a thermally sprayed yttrium oxide-containing coating, the contamination of the wafer during the etching process in the plasma reactor was reduced, and the coating was essentially oxidized. Yttrium composition. The test was carried out on a 9400DFM plasma reactor with a chamber liner completely sealed with a coating containing yttria, a bottom ring coated with a coating containing yttria, and a coating coated with yttria containing The base ring screw cap and the quartz window in the reactor chamber.

The reactor chamber was prepared by a wet cleaning procedure including wiping clean with 6% H2O+isopropanol and a wet cleaning recovery procedure using six oxide wafers and the following process parameters: 15mT chamber pressure/800W top coil power/ 0W bottom electrode power/100sccm SF6/20sccm Cl2/50sccmO2/8 Torr He back cooling/300 seconds etching time. Ten bare silicon wafers were used to adjust the reactor chamber with the following process parameters: break through etch: 4 millitorr chamber pressure/600 watts top coil power/65 watts bottom electrode power/100sccm HBr/10sec etching Time; main etching: 6 millitorr chamber pressure/350 watts top coil power/20 watts bottom electrode power/180sccm HBr/65sec etching time; and over-etching: 80mT chamber pressure/350 watts top coil power/75 watts bottom electrode power/ 150sccmHBr/150sccm He/5sccm O2/90sec etching time. After each wafer, high-pressure waferless automatic cleaning is used.

Use the following procedure to measure the contamination of the wafer. Etch a 1k thermal oxide wafer with the following process parameters: Through etching: 4 mTorr chamber pressure/600 watts top coil power/65 watts bottom electrode power/100sccm HBr/10sec etching time; main etching: 6 mTorr chamber Pressure/350 watts top coil power/20 watts bottom electrode power/180sccm HBr/65sec etching time; and over-etching: 80 mtorr chamber pressure/350 watts top coil power/75 watts bottom electrode power/150sccm HBr/150sccm He/5sccm O2/90sec etching time. The silicon wafer was etched with the following process parameters: 5mT chamber pressure/250W top coil power/150W bottom electrode power/50sccm Cl2/120sec etching time. After etching, the thermal oxide wafer and the main silicon wafer were analyzed for contamination using ICP-MS.

Thermal oxide wafers and bare silicon wafers are placed in a reactor chamber and etched using the above process parameters, where components including yttrium oxide coatings may or may not be present in the reactor chamber. During the testing process with the component containing the yttrium oxide coating in the reactor chamber, the actual amount of the anodized aluminum component in the reactor chamber was exposed to the plasma during the test. After etching, the surface concentration of Al, Cr, Cu, Fe, Ni, Na, and Y was measured on the wafer in units of 1010 atoms/cm2. The control oxide wafers not placed in the reactor chamber are also analyzed to determine the degree of contamination measured for the etched wafers originating from the reactor chamber.

Figure 7 shows the results of the contamination analysis of the wafer. "Coated" refers to yttria-coated components that are present in the reactor chamber, and "uncoated" refers to yttria-coated components that are not present. Comparing the test results of the same wafer type, that is, thermal oxide wafers and bare silicon wafers, the test results are shown on a unit-to-unit basis. The results of the reactor chamber including the yttria-coated components are significantly lower than the components The result of the above reactor chamber containing plasma exposed and anodized aluminum surfaces. For example, the measured aluminum concentration of the "uncoated" bare silicon wafer is about 87×1010 atoms/cm2, and the measured aluminum concentration of the "coated bare silicon wafer is about 12×1010 atoms/cm2. cm2. Moreover, the measured chromium concentration of the "uncoated" bare silicon wafer was about 7×1010 atoms/cm2, while the measured aluminum concentration of the "coated" bare silicon wafer was about 109 atoms/cm2. It is the detection limit of the measuring equipment. For thermal oxide wafers, the following results are obtained in units of 1010 atoms/cm2: Al: "uncoated", 2000, "coated", 480; Cu: "uncoated" , 15, "coated", 4; Fe: "uncoated", 72, "coated", 280; and Ni: "uncoated", 10, "coated", 2. After the test, it was determined that there was a source of Fe contamination during the test, which increased the Fe content in the wafer.

As shown in Figure 7, the yttrium oxide content has no meaning for all tested wafers. For bare silicon wafers, no yttrium oxide was detected above the detection limit of the measurement equipment. This result proves the robustness of the yttria-containing coating in a plasma environment. Therefore, the yttria-containing coating can achieve a very low level of yttrium oxide contamination on the wafer.

Therefore, the above test results prove that the yttrium oxide-containing coating can achieve a significant reduction in the erosion rate of the components exposed to the plasma environment. As a result, the yttria-containing coating can use yttria and other units forming yttria-coated parts to minimize contamination of the semiconductor substrate in the plasma etching reactor.

The yttria-containing coating can provide a very strong and wear-resistant surface. The coating is desirably not a material that reacts with the processing chamber gas, and is a chemically inert material to produce low or no particle pollution, little or no corrosion, little or no metal pollution and/or little or no volatility Etching product. Therefore, yttrium oxide-containing coatings can reduce the degree of metal and particulate contamination, reduce costs by increasing the life of consumables, reduce method shifts, and reduce the corrosion of chamber parts and substrates.

Although the present invention has been described in detail with reference to its specific embodiments, those skilled in the art should understand that various changes and modifications can be made without departing from the scope of the appended claims, and equivalents can be used.