Process kit with protective ceramic coating for hydrogen and ammonia plasma applications

Abstract

A method and apparatus for processing using hydrogen plasma is described herein. A processing chamber includes a plurality of chamber components. The plurality of chamber components can be coated with a yttria zirconia composition such as Y2O3-ZrO2 solid solution. Some of the plurality of chamber components are replaced with bulk yttria zirconia ceramic. Yet other chamber components are replaced with similar components of different materials.

Description

Technical Field

[0001] Embodiments of this disclosure generally relate to ceramic-coated components and substrate processing chambers including them. Background Technology

[0002] In the semiconductor industry, device dimensions are constantly shrinking. Some manufacturing processes include plasma etching and plasma cleaning processes, which expose the substrate to a high-speed stream of plasma to etch or clean it. Hydrogen plasma processes are particularly useful, but they are highly corrosive and can corrode components within the processing chamber. The corrosion of the chamber components generates particles that contaminate the processed substrate and lead to device defects.

[0003] As device geometry shrinks, susceptibility to defects increases, and requirements for particulate contamination become more stringent. Consequently, the permissible level of particulate contamination may decrease with shrinking device geometry. To minimize particulate contamination introduced by plasma etching and / or plasma cleaning processes, plasma-resistant chamber materials have been developed. Examples of such plasma-resistant materials include ceramics composed of Al₂O₃, AlN, SiC, Y₂O₃, quartz, and ZrO₂. Different ceramics offer different material properties, such as plasma resistance, rigidity, flexural strength, thermal shock resistance, etc. Furthermore, different ceramics have different material costs.

[0004] The location and characteristics of different ceramic coatings or ceramic replacement components significantly affect particle deposition on the substrate. Therefore, a combination of ceramic coatings and ceramic components is needed to minimize particle deposition on the substrate, while maintaining the structural integrity of the chamber and reducing overall cost. Summary of the Invention

[0005] This disclosure generally relates to an apparatus for substrate processing, including a chamber body, a lower liner disposed within the chamber body, an upper liner disposed on top of the lower liner and within the chamber body, a liner door disposed through the upper liner and the chamber body, a chamber cover disposed on top of the chamber body, and a gas nozzle disposed through the chamber cover. Each of the lower liner, upper liner, and liner door further includes a sprayed yttrium zirconium oxide layer disposed thereon, and the gas nozzle is a bulk ceramic gas nozzle.

[0006] Another embodiment of an apparatus for substrate processing includes a chamber body, a lower liner disposed within the chamber body, an upper liner disposed on top of the lower liner and within the chamber body, a liner door disposed through the upper liner and the chamber body, a chamber cover disposed on top of the upper liner, a gas nozzle disposed through the chamber cover, and one or more nickel-plated or stainless steel gaskets disposed between the lower liner and the upper liner, between the upper liner and the chamber cover, and between the lower liner and a substrate support base. The lower liner, upper liner, and liner door further include a sprayed yttrium zirconium oxide layer disposed thereon, wherein the yttrium zirconium oxide further comprises a Y₂O₃-ZrO₂ solid solution. The gas nozzle is a bulk ceramic gas nozzle.

[0007] Another embodiment of an apparatus for substrate processing includes a chamber body, a lower liner disposed within the chamber body, an upper liner disposed on top of the lower liner and within the chamber body, a liner door disposed through the upper liner and the chamber body, a chamber cover disposed on top of the upper liner, a gas nozzle disposed through the chamber cover, an induction coil disposed on top of the chamber cover, and a shielding electrode disposed between the induction coil and the chamber cover. Each of the lower liner, the upper liner, and the liner door further comprises a sprayed yttrium zirconium oxide layer disposed thereon. The gas nozzle is a bulk ceramic gas nozzle. The thickness of the sprayed yttrium zirconium oxide layer is from about 25 micrometers to about 300 micrometers, and the sprayed yttrium zirconium oxide layer is a purified yttrium zirconium oxide coating having a concentration of 99% or greater of Y₂O₃ and ZrO₂. Attached Figure Description

[0008] To gain a more detailed understanding of the features described above in this disclosure, a more specific description of the disclosure, which has been briefly summarized above, can be obtained by referring to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only exemplary embodiments and are not intended to limit the scope thereof, as this disclosure allows for other equivalent and effective embodiments.

[0009] Figure 1 This is a schematic cross-sectional view of a processing chamber assembly according to one embodiment.

[0010] Figure 2 This is a schematic cross-sectional view of a ceramic-coated chamber component.

[0011] Figure 3 It is a method for processing substrates.

[0012] Figure 4 This is a chart showing the level of particle contamination on the substrate.

[0013] Figure 5 This is a graph showing substrate particle contamination caused by the processing chamber cover.

[0014] For ease of understanding, the same reference numerals have been used to identify common elements in the figures where possible. It is anticipated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. Detailed Implementation

[0015] The embodiments disclosed herein include a processing chamber for substrate processing. The processing chamber can be used during hydrogen plasma processing of the substrate. The processing chamber includes multiple chamber components. One or more of the multiple chamber components are coated with a yttrium zirconium oxide composition such as a Y₂O₃-ZrO₂ solid solution. Some of the multiple chamber components are replaced with bulk yttrium zirconium oxide ceramic. Still other chamber components are replaced with similar components of different materials. Coating and component replacement are performed to reduce particulate contamination of the substrate during substrate processing operations involving hydrogen plasma.

[0016] Figure 1 This is a schematic cross-sectional view of a processing chamber assembly 100 according to one embodiment. As shown, the processing chamber assembly 100 includes a plasma processing chamber 101, a plasma source 160, a bias power system 161, and a controller 146. The plasma processing chamber 101 provides a chamber for processing a thin film already formed on the surface of a substrate 128. Typically, the thin film is deposited on the surface of the substrate 128 in a separate thin film deposition chamber coupled to a cluster of tools shared within the processing chamber assembly 100. In some embodiments, the plasma processing chamber 101 may also be additionally configured to deposit a thin film layer on the surface of the substrate. The plasma source 160 converts a gaseous mixture 134 (such as a hydrogen-containing gaseous mixture) into plasma 136, which bombards the substrate 128 to alter the properties of the film grown thereon. The bias power system 161 provides a voltage bias across the entire substrate 128 to facilitate the processing. The controller 146 implements specific processing conditions for both film growth and film processing. The entire processing chamber assembly 100 is configured to grow or process films formed on substrate 128 using a specific plasma process, which is provided by commands supplied via controller 146. The thin film processing is assisted by plasma source 160 and bias power system 161.

[0017] As shown in the figure, the plasma processing chamber 101 includes a chamber body 106, a chamber cover 108, a substrate support base 104, an electrostatic chuck 105, an electrical ground 116, a gas panel 130, a gas nozzle 131 with an inlet 132, a throttle valve 138, a vacuum pump 140, and a gas source 142. The plasma processing chamber 101 can be any suitable plasma processing chamber, such as an inductively coupled plasma (ICP) processing chamber. In one embodiment, the processing chamber 101 and the thin film deposition chamber (not shown) are part of the same cluster tool (not shown). The cluster tool (e.g., from Applied Materials Inc.) The system is configured to allow the transfer of substrates between the thin film deposition chamber and the processing chamber 101 without exposure to air.

[0018] like Figure 1 As shown, the processing chamber 101 includes a chamber body 106, a dielectric chamber cover 108, and a substrate support base 104 disposed within the chamber body 106. The chamber body 106 and the dielectric chamber cover 108 help isolate the internal space of the processing chamber 101 from the external environment. Typically, the chamber body 106 is coupled to an electrical ground 116. The chamber body 106 can also be described as the chamber wall of the processing chamber 101. The chamber body 106 includes the side walls and bottom wall of the processing chamber 101. The dielectric chamber cover 108 can be made of any suitable dielectric material (such as quartz). For some embodiments, the dielectric chamber cover 108 can take different shapes (e.g., dome shape). In some embodiments, as further described herein, the chamber cover 108 can be coated with a ceramic coating. A gas nozzle 131 having an inlet 132 is fluidly connected to a gas panel 130 and the processing chamber 101. The gas nozzle 131 is any suitable gas nozzle and comprises bulk ceramic. Bulk ceramics are described further below.

[0019] An opening 154 is formed through the chamber body 106. The size of the opening 154 is adjusted to allow the substrate to be conveyed in and out of the processing chamber 101. The opening 154 is located on the side wall of the chamber body 106. The opening 154 is part of a valve between the processing chamber assembly 100 and a cluster tool (not shown). The opening 154 may be part of a slit valve or a clamping and sealing valve assembly. The gasket door 156 of the valve, located adjacent to the opening 154, is made of tin or lead. The gasket door 156 includes a ceramic gasket, such as yttrium zirconium oxide. The ceramic gasket may be similar to other ceramic gaskets described herein.

[0020] Detector 122 is attached to chamber body 106 to facilitate the determination of when to excite the gas mixture within chamber 101 into plasma. For example, detector 122 may detect radiation emitted by the excited gas or use optical emission spectroscopy (OES) to measure the intensity of one or more wavelengths of light associated with the generated plasma. The entire plasma source 160 utilizes the gas mixture 134 to generate plasma 136 to process the deposited thin film.

[0021] The chamber body 106 includes an upper chamber body 111 and a lower chamber body 113. The upper chamber body 111 is the upper portion of the chamber body 106, such that the upper chamber body 111 includes an opening 154, a detector 122, and a throttle valve 138 disposed therein. The upper chamber body 111 is adjacent to the chamber cover 108. The upper chamber body forms at least a portion of the processing chamber 101. The upper chamber body 111 further includes an upper liner 109 lined inside the upper chamber body 111.

[0022] The lower chamber body 113 is the lower portion of the chamber body 106, such that the lower chamber body 113 includes a vacuum pump 140 and a base 104 disposed therein. The vacuum pump 140 is disposed at an opening within the lower chamber body 113. The base 104 is disposed on top of a portion of the lower chamber body 113. The lower chamber body 113 is disposed below the upper chamber body 111. The lower chamber body 113 forms at least a portion of the processing chamber 101. The lower chamber body 113 further includes a lower liner 107 lined inside the upper chamber body 111.

[0023] Upper gasket 109 and lower gasket 107 are respectively disposed on the inner surfaces of upper chamber body 111 and lower chamber body 113. Upper gasket 109 and lower gasket 107 are copper with a tin, lead, or tin and lead coating. In some embodiments, the copper may be beryllium copper. Upper gasket 109 and lower gasket 107 further include a ceramic coating. The ceramic coating is a yttrium zirconium oxide coating. The yttrium zirconium oxide coating is described in more detail herein.

[0024] In operation, substrate 128 (such as a semiconductor substrate) may be placed on electrostatic chuck 105, and process gas may be supplied from gas panel 130 through inlet 132 to facilitate the formation of gaseous mixture 134. According to one embodiment, substrate 128 is a bare silicon wafer. In another embodiment, as commonly used in logic gate, I / O gate, field-effect transistor, FINFET, or memory applications, substrate 128 is a patterned silicon wafer. Common process gases that can be used in one or more processes described herein are described below. Gaseous mixture 134 may be excited into plasma 136 within process chamber 101 by applying power from RF power source 114. Pressure within the interior space of process chamber 101 may be controlled using throttle valve 138 and vacuum pump 140. In some embodiments, the temperature of the chamber body 106 can be controlled using a heating element that travels through the chamber body 106 and contains a liquid conduit (not shown) or is embedded in the chamber body 106 (e.g., a heating cylinder or coil) or wrapped around the processing chamber 101 (e.g., a heater package or belt).

[0025] The temperature of substrate 128 can be controlled by controlling the temperature of base 104. The temperature of electrostatic chuck 105 can be controlled within a range of 20 to 500°C using heating and cooling elements. The substrate temperature is actively controlled by "clamping" substrate 128 to the substrate support surface of electrostatic chuck 105 during processing. Temperature control of electrostatic chuck 105 and substrate, due to ion bombardment, helps reduce unwanted temperature increases via cooling elements embedded in base 104. Helium (He) gas from gas source 142 is supplied via gas conduit 144 to channels (not shown) formed in the base surface below substrate 128. Helium facilitates heat transfer between base 104 and substrate 128. During processing, base 104 can be heated to a steady-state temperature, and subsequently, helium promotes uniform heating of substrate 128. The base 104 can be heated by a heating element (not shown), such as a resistance heater embedded in the base 104, or a lamp typically aimed at the base 104 or the substrate 128 (when on the base). Using this type of thermal control, the substrate 128 can be maintained at a first temperature between about 20 and 500°C. Components of the plasma source 160 provide an environment for film growth and densification.

[0026] A plasma shielding ring 129 is disposed around the outer edge of the substrate 128 and on top of the base 104. The plasma shielding ring 129 surrounds the substrate 128. The plasma shielding ring 129 improves the uniformity of processing (e.g., deposition and etching) near the edge of the substrate 128. The plasma shielding ring 129 further protects the lower edge of the substrate 128. In embodiments as described herein, the plasma shielding ring 129 is a bulk ceramic plasma shielding ring, such that the plasma shielding ring 129 is a yttrium zirconium oxide plasma shielding ring or an alumina plasma shielding ring 129. The plasma shielding ring 129 may also be an alumina ring with a yttrium zirconium oxide coating. The yttrium zirconium oxide coating may be similar to any of the yttrium zirconium oxide coatings described herein. In some embodiments, the plasma shielding ring 129 comprises two attachable / detachable plasma shielding ring components, such that the two attachable plasma shielding ring components are engaged with each other to form a multi-component plasma shielding ring 129. Each of the sub-components of the two plasma shielding rings 129 is individually coated using any of the ceramic coatings described herein.

[0027] The base 104 is connected to the lower chamber body 113 and lower gasket 107 of the chamber body 106 via one or more fasteners 164. One or more fasteners 164 are disposed through the bottom portion of the base 104, the lower chamber body 113, and the lower gasket 107. The one or more fasteners 164 may be screws, bolts, or any other suitable fasteners. The one or more fasteners 164 include lead and tin. In some embodiments, the one or more fasteners 164 may be copper fasteners with a lead or tin coating. A fastener cap 162 is disposed above a portion of the fastener 164 disposed within the plasma processing chamber 101. The fastener cap 162 is a bulk ceramic portion, such as a yttrium zirconium oxide ceramic portion. Alternatively, the fastener cap 162 may be an alumina ceramic portion. The composition of the bulk ceramic fastener cap 162 is further described herein. One or more fasteners 164 and the fastener cap 162 disposed on the fasteners 164 are disposed around the outer diameter of the base of the base 104. One or more fasteners 164 connect the base 104, the lower chamber body 113, and the lower liner 107 and secure the components together.

[0028] As shown in the figure, the plasma source 160 includes a coil element 110, a first impedance matching network 112, an RF power source 114, an electrical ground 117, a shielding electrode 118, an electrical ground 119, a switch 120, and a detector 122. A radio frequency (RF) antenna, including at least one induction coil element 110, is disposed on the dielectric chamber cover 108. In one configuration, such as... Figure 1As shown, two coaxial coil elements arranged around the central axis of the processing chamber are driven at an RF frequency to generate plasma 136 in the processing region of the processing chamber assembly 100. In some embodiments, induction coil elements 110 may be arranged around at least a portion of the chamber body 106. One end of the induction coil element 110 may be coupled to an RF power source 114 through a first impedance matching network 112, and the other end may be connected to an electrical ground 117 as shown. The power source 114 is typically capable of generating up to 4 kilowatts (kW) at a frequency of 13.56 MHz. The RF power supplied to the induction coil element 110 may be pulsed (i.e., switched between on and off states) or cyclic (i.e., changed from a high level to a low level) at a frequency varying from 1 to 100 kHz. The average ion density of plasma 136 may range from 1E10 to 1E12 ions per cubic centimeter (cm³). -3 The plasma density can be measured using any conventional plasma diagnostic technique, such as by using self-excited electron plasma resonance spectroscopy (SEERS), a Langmuir probe, or other suitable techniques. It is believed that in... Figure 1 The inductively coupled coaxial coil element 110 shown in the figure offers significant advantages over conventional plasma source configurations, including capacitive coupling and plasma source configurations, in terms of controlling and generating high-density plasma.

[0029] The shielding electrode 118 is inserted between the induction coil element 110 of the RF antenna and the dielectric chamber cover 108. Alternatively, the shielding electrode 118 may be electrically floated or coupled to the electrical ground 119 by any suitable means, such as for establishing and disconnecting the electrical connection. Figure 1 The switch 120 is shown in the image.

[0030] As shown, the bias power system 161 includes a second impedance matching network 124 and a bias power source 126. The base 104 is coupled to the bias power source 126 via the second impedance matching network 124. Similar to the RF power source 114, the bias power source 126 is typically capable of generating an RF signal with a drive frequency ranging from 1 to 160 MHz and a power between approximately 0 kW and approximately 3 kW. Using a frequency of 13.56 MHz or 2 MHz, the bias power source 126 can generate power between approximately 1 W and 1 kW at frequencies ranging from 2 to 160 MHz. Depending on the application, the bias power source 126 can be a direct current (DC) or pulsed DC source. In some embodiments, electrodes coupled to the bias power source 126 are disposed within an electrostatic chuck 105. The bias power system 161 provides a substrate voltage bias across the entire substrate 128 to facilitate processing of the deposited thin film. In one embodiment, the RF bias provides high-energy ions with ion energies up to 2000 eV.

[0031] As shown, controller 146 includes a central processing unit (CPU) 148, memory 150, and support circuitry 152. Controller 146 can interface with an RF power source 114, a switch 120, a detector 122, and a bias power source 126. Controller 146 can be any suitable type of general-purpose computer processor that can be used in an industrial environment for controlling various chambers and subprocessors. Memory 150, or other computer-readable media for CPU 148, can be one or more of any readily available memory forms, such as random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, or any other form of digital storage (local or remote). Support circuitry 152 can be coupled to CPU 148 to support the processor in a conventional manner. This circuitry may include caches, power supplies, clock circuits, input / output (I / O) circuitry and subsystems, and the like. For some embodiments, the techniques disclosed herein for stimulating and sustaining plasma may be stored in memory 150 as software routines. Software routines may also be stored and / or executed by a second CPU (not shown), which is located remotely to the hardware controlled by CPU 148. Controller 146 provides instructions to the processing chamber assembly 100 and the various sub-components mentioned above for temperature control, bias voltage, gas flow rate, and the like.

[0032] One or more gaskets 166 are disposed between the chamber cover 108 and the chamber body 106, such that one or more gaskets 166 are disposed between the chamber cover 108 and the upper chamber body 111. One or more gaskets 166 assist in maintaining a seal between the chamber cover 108 and the chamber body 106, while also improving electrical conductivity between the chamber cover 108 and the chamber body 106. Gaskets 166 are nickel-plated copper gaskets or stainless steel gaskets. Gaskets 166 are nickel-plated to reduce particulate contamination caused by gaskets 166 during substrate processing. Using stainless steel gaskets similarly reduces particulate contamination within the processing chamber. It has been found that using metals with low melting point temperatures as gaskets 166 (such as lead, tin, or indium-coated gaskets) can generate spherical or disc-shaped defects on the substrate. Low melting point metals (such as lead and tin) are extracted by hydrogen plasma during processing. Nickel-plated gaskets 166 have been found to significantly reduce particulate contamination of the substrate caused by gaskets 166. The nickel plating on gasket 166 has a thickness ranging from about 1 micrometer to about 3 mm, such as about 25 micrometers to about 100 micrometers, or about 50 micrometers to about 80 micrometers. Similarly, it has been shown that replacing low-melting-point metal gaskets with stainless steel gaskets reduces particulate contamination caused by conventional gaskets.

[0033] One or more washers 168 are disposed between the upper chamber body 111 and the lower chamber body 113. One or more washers 166 assist in maintaining a seal between the upper chamber body 111 and the lower chamber body 113, while also providing a conductive path between the upper chamber body 111 and the lower chamber body 113. Washers 166 are nickel-plated copper washers or stainless steel washers.

[0034] One or more washers 170 are disposed between the lower chamber body 113 and the base 104. The washers 170 assist in maintaining a seal between the lower chamber body 113 and the base 104. The washers 170 further improve the electrical connection between the lower chamber body 113 and the base 104. The washers 170 are nickel-plated copper washers or stainless steel washers. In some embodiments, the washers 170 may be disposed between the lower gasket 107 and the base 104.

[0035] Figure 2 This is a schematic cross-sectional view of a portion of a ceramic-coated chamber component 200. The ceramic-coated chamber component 200 may be any of a chamber cover 108, an upper liner 109, a lower liner 107, a liner door 156, a base 104, and an electrostatic chuck 105. The ceramic-coated chamber component 200 includes a component 202 and a ceramic coating 204. Component 202 is any of the chamber cover 108, upper liner 109, lower liner 107, liner door 156, base 104, or electrostatic chuck 105.

[0036] Component 202 may include multiple layers, such as a base copper layer coated with lead or tin. The copper layer may be the primary component of each of the chamber components 200. The base lead or tin layer may be a layer between the primary component and the ceramic coating 204.

[0037] In some embodiments, component 202 is a single material and does not include multiple layers. The single material may comprise any of alumina, quartz, or copper. Component 202 has a ceramic coating 204 disposed directly thereon.

[0038] Ceramic coating 204 is a coating deposited on top of component 202 to minimize contaminant particles deposited on a substrate (such as substrate 128) within the processing chamber assembly 100. Ceramic coating 204 may comprise a Y₂O₃-ZrO₂ solid solution. The Y₂O₃-ZrO₂ solid solution is a solid-phase solution of Y₂O₃ and ZrO₂ compounds. The Y₂O₃ and ZrO₂ compounds are a single homogeneous phase. The Y₂O₃-ZrO₂ solid solution is about 20 molecular percent to about 50 molecular percent of ZrO₂. In some embodiments, the Y₂O₃-ZrO₂ solid solution is about 25 molecular percent to about 45 molecular percent of ZrO₂, such as about 30 molecular percent to about 40 molecular percent of ZrO₂. In some embodiments, a small amount of liquid Y₂O residue is present along with the Y₂O₃-ZrO₂ single phase.

[0039] The ceramic coating 204 may have a porosity of about 2% to about 10% (e.g., less than approximately 5% in one embodiment). In some embodiments, the porosity of the ceramic coating 204 is less than about 3%, such as less than 2%, such as less than 1%. The ceramic coating 204 has a hardness of approximately 3-8 gigapascals (GPa) (e.g., greater than approximately 4 GPa in one embodiment) and a thermal shock resistance of approximately 8-20 megapascals (MPa) (e.g., greater than approximately 10 MPa in one embodiment). Furthermore, the ceramic coating may have an adhesion strength of approximately 4-20 MPa (e.g., greater than approximately 14 MPa in one embodiment). The adhesion strength can be determined by applying a force (e.g., measured in megapascals) to the ceramic coating until the ceramic coating peels off from the ceramic substrate.

[0040] The ceramic coating 204 is formed by spraying or growing a ceramic coating on a ceramic substrate. The component 202 is formed by a sintering process or machining. In embodiments where the ceramic coating 204 is sprayed, the ceramic coating 204 is sprayed yttrium zirconium oxide. The sprayed yttrium zirconium oxide has a thickness of about 10 micrometers to about 500 micrometers, such as about 15 micrometers to about 400 micrometers, about 20 micrometers to about 300 micrometers, or about 20 micrometers to about 250 micrometers. The component coated with yttrium zirconium oxide allows the thickness of the ceramic coating 204 to be greater than that of a physical vapor deposition (PVD) yttrium zirconium oxide coating deposited using other ceramic deposition processes, and prevents the ceramic coating 204 from cracking at thicknesses greater than about 15 micrometers. The increased thickness prevents metallic contaminants from passing through the ceramic coating 204 during processing and reduces maintenance frequency. Sprayed yttrium zirconium oxide can be easily applied to large components 202, such as the upper liner 109, lower liner 107, liner door 156, and base 104. The sprayed yttrium zirconium oxide is applied using thermal spraying and / or plasma spraying techniques. Thermal spraying and plasma spraying techniques melt materials (e.g., ceramic powder) and spray the molten material onto component 202. The ceramic coating can have structural properties significantly different from those of the bulk ceramic material (e.g., a ceramic substrate).

[0041] Alternatively, the ceramic coating 204 is formed by depositing a ceramic coating on a ceramic substrate via a PVD coating process. In embodiments where the ceramic coating 204 is deposited using a PVD coating process, the ceramic coating 204 is PVD-coated yttrium zirconium oxide. The PVD-coated yttrium zirconium oxide has a thickness of less than about 15 micrometers, such as less than about 10 micrometers, such as about 0.5 micrometers to about 10 micrometers, such as about 0.75 micrometers to about 7.5 micrometers, such as about 1 micrometer to about 5 micrometers. The PVD-coated yttrium zirconium oxide is applied to a smaller component 202, such as a chamber cover 108. The PVD-coated yttrium zirconium oxide has a lower porosity compared to sprayed yttrium zirconium oxide. Sprayed zirconium oxide has a porosity of about 0.5% to about 5%, such as about 1% to about 4%, such as about 2% to about 3%. PVD-coated yttrium zirconium oxide has a porosity of about 0% to about 1%, such as about 0% to about 0.5%, such as about 0% to about 0.25%.

[0042] The PVD-coated yttrium zirconium oxide is a relatively thin coating. Because the PVD coating can withstand the effects of hydrogen plasma in the adjacent chamber cover 108, it is advantageously used on the chamber cover 108. The PVD coating is also easier to deposit on flat surfaces, such as the bottom surface of the chamber cover 108. The PVD coating of the second yttrium zirconium oxide layer is more uniform and has a higher density compared to spraying on a sprayed yttrium zirconium oxide coating. The PVD coating process can be replaced by CVD or ALD coating processes. CVD and ALD processes can produce similar results to PVD coatings, such as similar porosity and thickness.

[0043] In some embodiments, a laminated or sintered yttrium zirconium oxide layer is formed on a substrate, such as on a gas nozzle 131, a plasma shielding ring 129, a chamber cover 108, and / or a fastener cover 162. The laminated or sintered yttrium zirconium oxide layer can be formed using two different deposition techniques and can have altered physical properties. In some embodiments, the laminated or sintered yttrium zirconium oxide layer is formed by depositing a PVD-coated yttrium zirconium oxide layer on top of a sprayed yttrium zirconium oxide layer. Depositing a PVD-coated layer on top of a sprayed layer forms the laminated yttrium zirconium oxide layer. The laminated yttrium zirconium oxide layer is formed by depositing yttrium zirconium oxide one or more times consecutively via spraying and PVD coating.

[0044] Before forming a second yttrium zirconium oxide layer on the substrate, a sprayed yttrium zirconium oxide layer is formed on the substrate. The sprayed yttrium zirconium oxide layer is similar to the sprayed yttrium zirconium oxide layer described herein. The sprayed yttrium zirconium oxide layer is a low-stress layer, allowing the sprayed yttrium zirconium oxide to adhere well to the substrate with low stress. A PVD coating (such as PVD-coated yttrium zirconium oxide) is deposited on top of the sprayed yttrium zirconium oxide layer. When deposited on the substrate itself, the PVD-coated yttrium zirconium oxide layer is a higher-stress layer compared to the sprayed yttrium zirconium oxide layer. By depositing a PVD-coated yttrium zirconium oxide layer on top of a sprayed yttrium zirconium oxide layer, the stress within the PVD-coated yttrium zirconium oxide layer is reduced, resulting in lower stress within the PVD-coated yttrium zirconium oxide layer compared to the higher stress layer of the sprayed yttrium zirconium oxide layer. This is because the sprayed yttrium zirconium oxide layer acts as a bridging layer. Depending on the structure, porosity, and thickness of the sprayed and PVD-coated yttrium zirconium oxide layers, the stress within the coating is reduced by approximately 10% to approximately 90% compared to the PVD coating itself.

[0045] Another embodiment of the laminated yttrium zirconium oxide layer is a sintered yttrium zirconium oxide layer. In some embodiments, the sintered yttrium zirconium oxide layer is formed on the chamber cover 108. The sintered yttrium zirconium oxide layer has almost zero porosity, making it similar to the properties of bulk yttrium zirconium oxide ceramic materials. In some embodiments, the porosity of the sintered yttrium zirconium oxide layer is less than about 0.2%, such as less than about 0.1%, such as less than about 0.05%, such as less than 0.01%. In some embodiments, the sintered yttrium zirconium oxide layer has a thickness of about 0.5 mm to about 10 mm, such as about 1 mm to about 5 mm, such as about 1 mm to about 3 mm. The sintered yttrium zirconium oxide layer is formed using a sintering process, wherein yttrium zirconium oxide powder is pressed onto the surface of the chamber cover 108 to form the sintered yttrium zirconium oxide layer. The sintered yttrium zirconium oxide layer is considered a laminate because it is coated on a bulk ceramic substrate, such as a bulk ceramic chamber cover 108. Alternatively, a lamination process similar to that of yttrium zirconium oxide, involving repeated spraying and PVD coating, can be performed. After repeated lamination and PVD coating of yttrium zirconium oxide, the layer can be subsequently pressurized and heated to alter the final layer structure and densify it to resemble a sintered yttrium zirconium oxide layer.

[0046] The sintered yttrium zirconium oxide layer is thicker than either a sprayed or PVD-coated yttrium zirconium oxide layer. The sintered yttrium zirconium oxide layer can be used as a ceramic coating 204 for some components of the processing chamber assembly 100, such as the chamber cover 108. Compared to either a sprayed or PVD-coated yttrium zirconium oxide layer, using either a laminated or sintered yttrium zirconium oxide layer as the ceramic coating 204 for the chamber cover 108 significantly reduces contaminant particles deposited on the substrate by the cover 108 because the laminated or sintered yttrium zirconium oxide layer better withstands the high hydrogen plasma concentration adjacent to the chamber cover 108.

[0047] All sprayed, PVD-coated, laminated, and sintered yttrium zirconium oxide layers can be formed from a Y₂O₃-ZrO₂ solid solution. The Y₂O₃-ZrO₂ solid solution is a purified Y₂O₃-ZrO₂ solution. The Y₂O₃-ZrO₂ solid solution is purified as a coating prior to deposition to reduce the amount of lead, tin, indium, and other low-melting-point metals within the Y₂O₃-ZrO₂ solid solution. The Y₂O₃-ZrO₂ solid solution is purified at least once to obtain a Y₂O₃ and ZrO₂ concentration of 99% or greater, such as 99.5% or greater, 99.9% or greater, or 99.99% or greater. In some embodiments, less than 0.2 nanograms per gram of tin and less than 15 nanograms per gram of lead are present in the Y₂O₃-ZrO₂ solid solution. In some embodiments, less than 0.2 nanograms per gram of tin and less than 0.1 nanograms per gram of lead are present in the Y₂O₃-ZrO₂ solid solution. In still other embodiments, less than 0.1 nanograms per gram of tin and less than 0.15 nanograms per gram of lead are present in the Y₂O₃-ZrO₂ solid solution. The Y₂O₃-ZrO₂ solid solution may have less than 0.05 nanograms per gram of tin and less than 0.01 nanograms per gram of lead. Reducing the concentration of lead and tin correspondingly reduces substrate contamination.

[0048] In some embodiments, component 202 does not have the ceramic coating 204. Component 202 may alternatively be a ceramic component itself. Component 202 that may be a ceramic component includes a gas nozzle 131, a plasma shielding ring 129, a chamber cover 108, and a fastener cover 162. Component 202 that is a bulk ceramic component may be an alumina (Al2O3), an Al2O3-Y2O3 component, or a yttrium zirconium oxide component. The yttrium zirconium oxide component is a bulk ceramic component. The yttrium zirconium oxide component has properties similar to those of a laminated yttrium zirconium oxide coating. The ceramic component has a porosity of less than about 0.2%, such as less than about 0.1%, less than about 0.05%, or less than 0.01%. The ceramic component has a concentration of 99% or greater for Y₂O₃ and ZrO₂, such as 99.5% or greater, 99.9% or greater, or 99.99% or greater. In some embodiments that can be combined with other embodiments, less than 0.2 nanograms per gram of tin and less than 15 nanograms per gram of lead are present in the yttrium zirconium oxide ceramic component. In some embodiments, less than 0.2 nanograms per gram of tin and less than 0.1 nanograms per gram of lead are present in the yttrium zirconium oxide ceramic component. In still other embodiments, less than 0.1 nanograms per gram of tin and less than 0.15 nanograms per gram of lead are present in the yttrium zirconium oxide ceramic component. The yttrium zirconium oxide ceramic component may have less than 0.05 nanograms per gram of tin and less than 0.01 nanograms per gram of lead.

[0049] Ceramic components are used to reduce the deposition of contaminant particles on the substrate. The ceramic components prevent the deposition of tin or lead particles and also reduce the amount of yttrium, zirconium, and silicon oxide (SiO2) particles emitted by the components in other ways. In some embodiments, the chamber cover 108 is alumina (Al2O3) bulk ceramic. In other embodiments, the chamber cover 108 is a bulk ceramic of an Al2O3-Y2O3 ceramic composite. The chamber cover 108 is replaced with bulk Al2O3 or Al2O3-Y2O3 ceramic to reduce the amount of SiO2 particles deposited on the substrate. The Al2O3 or Al2O3-Y2O3 chamber cover may still have a ceramic coating disposed thereon, such as ceramic coating 204. Ceramic coating 204 can be any of the coating types described herein, but the laminated yttrium zirconium oxide layer minimizes the amount of deposited contaminant particles.

[0050] Figure 3 This is a method 300 for processing a substrate. The method includes a first operation 302 of providing the substrate into a processing chamber, a second operation 304 of performing hydrogen plasma treatment, and a third operation 306 of removing the substrate from the processing chamber. Method 300 can be continuously cycled to process a large number of substrates over time.

[0051] The first operation 302, providing the substrate into the processing chamber, is performed by a robotic arm. The robotic arm can extend from a cluster tool into the processing chamber, such as the processing chamber assembly 100 described herein. A substrate (e.g., substrate 128) is deposited onto the top surface of an electrostatic chuck 105. The substrate may be a silicon substrate or a doped silicon substrate. In some embodiments, the substrate has undergone several additional processing steps to give it additional features not described herein. The substrate is then moved into the processing chamber to undergo a plasma processing process, such as a hydrogen plasma processing process.

[0052] The second operation 304, performing hydrogen plasma treatment, may include performing any type of substrate treatment in which hydrogen plasma treatment is utilized. Hydrogen plasma treatment may be a hydrogen etching process, whereby hydrogen radicals and / or hydrogen ions are used to etch the substrate surface and any features formed thereon. In other embodiments, hydrogen plasma treatment may be a cleaning process, whereby the substrate is cleaned by hydrogen plasma. Hydrogen plasma treatment may include carbon removal processes, removal of chlorine / fluoride from metal processes, oxygen removal processes, high-dielectric-constant metal gate stacking processes, and thread-intermediate contact processes. Current chamber hardware is generally incompatible with hydrogen plasma treatment (such as those performed in the second operation 304). Current chamber hardware generates a large amount of metallic contaminants and other contaminant particles. Using the chamber components described herein significantly reduces the amount of metallic and non-metallic contaminant particles deposited on the substrate during hydrogen plasma treatment processes.

[0053] The third operation 306, removing the substrate from the processing chamber, is performed after the hydrogen plasma treatment is completed. Removing the substrate from the processing chamber can be accomplished using a robotic arm similar to the one used in the first operation 302. The substrate can be removed from the processing chamber and transferred to the transfer chamber of the cluster tool. The substrate can then undergo further processing steps in other processing chambers connected to the cluster tool.

[0054] After completing the third operation 306, another substrate can be provided into the processing chamber and method 300 can be repeated. Method 300 can be repeated until maintenance is performed on the processing chamber. Due to the use of yttrium zirconium oxide coating and bulk ceramic portions throughout the processing chamber, method 300 can be performed more times before maintenance is completed compared to conventional processing chambers.

[0055] Figure 4 This is Graph 400, showing the level of particle contamination on the substrate. Similar to that performed in operation 304 of method 300, Graph 400 is a bar graph showing the concentration of aluminum particles on the substrate within a processing chamber (such as processing chamber assembly 100) after a hydrogen plasma processing process. In the hydrogen plasma processing process used to obtain the data for Graph 400, the process is performed at 450 degrees Celsius. 750 watts are applied via induction coil element 100, the pressure is maintained at 50 mTorr, the plasma processing chamber 101 is filled with 5% H2 and 95% Ar, and the process is performed for 90 seconds. Particles are shown as 1x10. 10 atoms / cm 2 The concentration of aluminum particles is determined by the presence of aluminum particles on the front side of a substrate (such as substrate 128).

[0056] The first pollutant source level 401, the second pollutant source level 402, the third pollutant source level 403, the fourth pollutant source level 404, the fifth pollutant source level 405, and the sixth pollutant source level 406 are each higher than the expected pollutant concentration threshold 410.

[0057] The desired pollutant concentration threshold of 410 is less than 1 x 10⁻⁶. 10 atoms / cm 2 As shown in Table 400, all first, second, third, fourth, fifth, and sixth pollutant sources 401, 402, 403, 404, 405, and 406 have a value greater than 1x10. 10 atoms / cm 2 Threshold. The first, second, third, fourth, fifth, and sixth contaminant sources 401, 402, 403, 404, 405, and 406 are non-ceramic or non-ceramic coated contaminant sources within the chamber assembly 100. By utilizing the coatings and component compositions described herein, the desired contaminant concentration threshold 410 is met and contaminants generated by each contaminant source are reduced or completely eliminated.

[0058] Figure 5 This is a graph 500 showing substrate particle contamination caused by the processing chamber cover. A first trend line 501 shows the amount of contaminant particle admixtures formed on the substrate (e.g., substrate 128) within a processing chamber (e.g., plasma processing chamber 101) when a quartz cover with a PVD yttrium zirconium oxide coating is used. A second trend line 502 shows the amount of contaminant particle admixtures formed on the substrate (e.g., substrate 128) within a processing chamber (e.g., plasma processing chamber 101) when an alumina chamber cover with a yttrium oxide (Y₂O₃) coating is used thereon.

[0059] Alumina chamber caps with a yttrium oxide coating provide more consistent lower particulate contamination across larger wafer processing cycles. Quartz caps, using laminated or sintered yttrium zirconium oxide coatings, can achieve similar or better results than alumina chamber caps with a yttrium oxide coating, resulting in less substrate particulate contamination.

[0060] The embodiments described herein can be modified to reduce particulate contamination on the substrate, lower overall cost, or improve the ease of application of coatings on chamber components. In one exemplary embodiment, the processing chamber assembly 100 includes a chamber cover 108 made of quartz, a gas nozzle 131 made of bulk yttrium zirconium oxide ceramic, a liner door 156 coated with a sprayed layer of yttrium zirconium oxide, a plasma shielding ring 129 made of bulk yttrium zirconium oxide ceramic, an upper liner 109 coated with a sprayed layer of yttrium zirconium oxide, a lower liner 107 coated with a sprayed layer of yttrium zirconium oxide, and a fastener cap 162 made of bulk yttrium zirconium oxide ceramic.

[0061] In another embodiment, the processing chamber assembly 100 includes a chamber cover 108 made of alumina or Al2O3-Y2O3 bulk ceramic with a PVD-coated yttrium zirconium oxide layer, a gas nozzle 131 made of bulk yttrium zirconium oxide ceramic, a gasket door 156 coated with a sprayed yttrium zirconium oxide layer, a plasma shielding ring 129 made of bulk yttrium zirconium oxide ceramic, an upper gasket 109 coated with a sprayed yttrium zirconium oxide layer, a lower gasket 107 coated with a sprayed yttrium zirconium oxide layer, and a fastener cover 162 made of bulk yttrium zirconium oxide ceramic.

[0062] In another embodiment, the processing chamber assembly 100 includes a chamber cover 108 made of an alumina or Al2O3-Y2O3 ceramic composite having a laminated or sintered yttrium zirconium oxide coating, a gas nozzle 131 made of bulk yttrium zirconium oxide ceramic, a gasket door 156 coated with a sprayed yttrium zirconium oxide layer, a plasma shielding ring 129 made of bulk yttrium zirconium oxide ceramic, an upper gasket 109 coated with a sprayed yttrium zirconium oxide layer, a lower gasket 107 coated with a sprayed yttrium zirconium oxide layer, and a fastener cover 162 made of bulk yttrium zirconium oxide ceramic.

[0063] In another embodiment, the processing chamber assembly 100 includes a chamber cover 108 made of alumina or an Al2O3-Y2O3 ceramic composite with a yttrium oxide coating, a gas nozzle 131 made of bulk yttrium zirconium oxide ceramic, a liner door 156 coated with a sprayed yttrium zirconium oxide layer, a plasma shielding ring 129 made of bulk yttrium zirconium oxide ceramic, an upper liner 109 coated with a sprayed yttrium zirconium oxide layer, a lower liner 107 coated with a sprayed yttrium zirconium oxide layer, and a fastener cover 162 made of bulk yttrium zirconium oxide ceramic.

[0064] In another embodiment, the processing chamber assembly 100 includes a chamber cover 108 made of quartz with a laminated or sintered yttrium zirconium oxide coating, a gas nozzle 131 made of bulk yttrium zirconium oxide ceramic, a liner door 156 coated with a sprayed yttrium zirconium oxide layer, a plasma shielding ring 129 made of bulk alumina ceramic, an upper liner 109 coated with a sprayed yttrium zirconium oxide layer, a lower liner 107 coated with a sprayed yttrium zirconium oxide layer, and a fastener cover 162 made of bulk yttrium zirconium oxide ceramic.

[0065] In another embodiment, the processing chamber assembly 100 includes a chamber cover 108 made of alumina or Al2O3-Y2O3 ceramic composite having a PVD-coated yttrium zirconium oxide layer, a gas nozzle 131 made of bulk yttrium zirconium oxide ceramic, a liner door 156 coated with a sprayed yttrium zirconium oxide layer, a plasma shielding ring 129 made of bulk alumina ceramic, an upper liner 109 coated with a sprayed yttrium zirconium oxide layer, a lower liner 107 coated with a sprayed yttrium zirconium oxide layer, and a fastener cover 162 made of bulk yttrium zirconium oxide ceramic.

[0066] In another embodiment, the processing chamber assembly 100 includes a chamber cover 108 made of an alumina or Al2O3-Y2O3 ceramic composite having a laminated or sintered yttrium zirconium oxide coating, a gas nozzle 131 made of bulk yttrium zirconium oxide ceramic, a liner door 156 coated with a sprayed yttrium zirconium oxide layer, a plasma shielding ring 129 made of bulk alumina ceramic, an upper liner 109 coated with a sprayed yttrium zirconium oxide layer, a lower liner 107 coated with a sprayed yttrium zirconium oxide layer, and a fastener cover 162 made of bulk yttrium zirconium oxide ceramic.

[0067] In another embodiment, the processing chamber assembly 100 includes a chamber cover 108 made of alumina or an Al2O3-Y2O3 ceramic composite with a yttrium oxide coating, a gas nozzle 131 made of bulk yttrium zirconium oxide ceramic, a liner door 156 coated with a sprayed yttrium zirconium oxide layer, a plasma shielding ring 129 made of bulk alumina ceramic, an upper liner 109 coated with a sprayed yttrium zirconium oxide layer, a lower liner 107 coated with a sprayed yttrium zirconium oxide layer, and a fastener cover 162 made of bulk yttrium zirconium oxide ceramic.

[0068] In some embodiments, the plasma shielding ring 129 may comprise a plasma shielding ring having a sprayed yttrium zirconium oxide layer. The sprayed yttrium zirconium oxide layer may be used for the plasma shielding ring 129 in any of the embodiments described herein. Alternatively, sprayed yttrium zirconium oxide may be used for the plasma shielding ring 129 not described herein, such as a quartz plasma shielding ring.

[0069] In other embodiments, any of the gas nozzle 131, plasma shielding ring 129, chamber cover 108, and fastener cover 162 may be made of bulk alumina ceramic. Furthermore, any of the gas nozzle 131, plasma shielding ring 129, chamber cover 108, or fastener cover 162 described in the embodiments herein may include a first yttrium zirconium oxide coating.

[0070] While the foregoing relates to embodiments of this disclosure, other and further embodiments of this disclosure may be designed without departing from its essential scope, the scope of which is defined by the appended claims.

Claims

1. An apparatus for substrate processing comprising: a chamber body comprising a lower chamber body and an upper chamber body; a lower liner disposed within the chamber body; a substrate support pedestal disposed within the chamber body; an upper liner disposed on top of the lower liner and within the chamber body; a liner door disposed through the upper liner and the chamber body, wherein each of the lower liner, the upper liner, and the liner door further comprise a sintered laminated yttria zirconia layer disposed thereon, wherein the sintered laminated yttria zirconia layer comprises a sprayed yttria zirconia layer and a PVD coated yttria zirconia layer deposited on top of the sprayed yttria zirconia layer; a chamber lid disposed on top of the chamber body; a gas nozzle disposed through the chamber lid, wherein the gas nozzle is made of bulk yttria zirconia ceramic; and one or more nickel plated gaskets disposed between the lower chamber body and the upper chamber body, between the upper chamber body and the chamber lid, and between the lower chamber body and substrate support pedestal.

2. The apparatus of claim 1, further comprising: an electrostatic chuck disposed within the chamber body; and a plasma shield ring disposed on top of the electrostatic chuck, wherein the plasma shield ring is a bulk ceramic plasma shield ring.

3. The apparatus of claim 1, further comprising: one or more fasteners disposed through the lower liner and the substrate support pedestal and securing the lower liner and the substrate support pedestal, each of the one or more fasteners having a bulk yttria zirconia ceramic fastener cap disposed thereon.

4. The apparatus of claim 1, wherein the chamber lid comprises an AI2O3 lid and a Y2O3 coating.

5. The apparatus of claim 1, wherein the chamber lid comprises an AI2O3-Y2O3 ceramic composite and a Y2O3 coating.

6. The apparatus of claim 1, wherein the chamber lid further comprises a quartz lid.

7. The apparatus of claim 1, wherein the chamber lid further comprises one of an alumina lid or an AI2O3-Y2O3 lid having a laminated or sintered yttria zirconia coating.

8. The apparatus of claim 1, wherein the yttria zirconia layer further comprises a Y2O3-ZrO2 solid solution.

9. An apparatus for substrate processing comprising: a chamber body comprising a lower chamber body and an upper chamber body; a lower liner disposed within the chamber body; a substrate support pedestal disposed within the chamber body; an upper liner disposed on top of the lower liner and within the chamber body; a liner door disposed through upper liner and the chamber body, wherein each of the lower liner, the upper liner, and liner door further comprise a sintered laminated yttria zirconia layer disposed there on, wherein the sintered laminated yttria zirconia layer further comprises a Y2O3-ZrO2 solid solu tion, and wherein the sintered laminated yttria zirconia layer comprises a sprayed yttr ia zirconia layer and a PVD coated yttria zirconia layer deposited on top the sprayed yttria zirconia layer. a chamber lid disposed on top of the upper liner; a gas nozzle disposed through the chamber lid, wherein the gas nozzle is made of bulk yttria zirconia ceramic; and one or more nickel plated gaskets disposed between the lower liner and the upper liner, between the upper liner and the chamber lid, and between the lower liner and the substrate support pedestal, and between the lower chamber body and the upper chamber body, between the upper chamber body and the chamber lid, and between the lower chamber body and substrate support pedestal.

10. The apparatus of claim 9, wherein a thickness of each of the sprayed yttria zirconia layers is about 25 microns to about 300 microns.

11. The apparatus of claim 9, wherein the chamber lid further comprises an alumina lid and a PVD coated yttria zirconia layer, wherein the PVD coated yttria zirconia layer has a thickness of about 0.5 microns to about 10 microns.

12. The apparatus of claim 9, wherein the sprayed yttria zirconia layer is a pure yttria zirconia coating having a concentration of Y2O3 and ZrO2 of 99% or greater.

13. The apparatus of claim 12, wherein the gas nozzle is a yttria zirconia ceramic gas nozzle having a porosity of equal to or less than about 0.2%.

14. The apparatus of claim 9, further comprising: an electrostatic chuck disposed within the chamber body; and a plasma shield ring disposed on top of the electrostatic chuck, wherein the plasma shield ring is bulk yttria zirconia ceramic or a Y2O3-ZrO2 coated alumina ring.

15. An apparatus for substrate processing, comprising: a chamber body comprising a lower chamber body and an upper chamber body; a lower liner disposed within the chamber body; a substrate support pedestal disposed within the chamber body; an upper liner disposed on top of the lower liner and within the chamber body; a liner door disposed through the upper liner and the chamber body, wherein each of the lower liner, the upper liner, and the liner door further comprise a sintered laminated yttria zirconia layer disposed thereon, wherein the sintered laminated yttria zirconia layer comprises a sprayed yttria zirconia layer and a PVD coated yttria zirconia layer deposited on top of the sprayed yttria zirconia layer; a chamber lid disposed on top of the upper liner; a gas nozzle disposed through the chamber lid, wherein the gas nozzle is made of bulk yttria zirconia ceramic; one or more nickel plated gaskets disposed between the lower chamber body and the upper chamber body, between the upper chamber body and the chamber, and between the lower chamber body and substrate support pedestal; an induction coil disposed above the chamber lid; and a shield electrode disposed between the induction coil and the chamber lid, wherein a thickness of the sprayed yttria zirconia layer is about 25 microns to about 300 microns and the sprayed yttria zirconia layer is a pure yttria zirconia coating with a concentration of Y2O3 and ZrO2 of 99% or greater.

16. The apparatus of claim 15, wherein the chamber lid further comprises an alumina lid and a PVD coated yttria zirconia coating.

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