EPI overlapping discs and rings

Abstract

Embodiments disclosed herein generally provide improved control of gas flow in a processing chamber. In at least one embodiment, the disc and gasket assembly includes a quartz disc having an outer diameter, a plurality of holes or slots formed in the quartz disc, and a quartz ring having an inner diameter less than the outer diameter of the quartz disc.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to gas flow in a processing chamber. More specifically, embodiments disclosed herein relate to overlapping disks and rings for preventing deposition on a lower window of an epitaxial deposition chamber. Background Art

[0002] Semiconductor substrates are processed for a variety of applications, including the fabrication of integrated and micro components. One method of substrate processing includes depositing a material, such as a dielectric material or a conductive metal, on an upper surface of the substrate. For example, epitaxy is a deposition process for growing thin, ultra-pure layers (generally composed of silicon or germanium) on a substrate surface. The material can be deposited in a horizontal flow chamber by flowing a process gas parallel to the substrate surface positioned on a support and thermally decomposing the process gas to deposit the material from the process gas onto the substrate surface. The film quality in epitaxial growth depends on the accuracy of the gas flow during film deposition. For example, a purge gas flow within the lower portion of the chamber can be used to help prevent or reduce the flow or diffusion of the process gas into the lower portion. However, the gas exchange between the process gas flow and the purge gas flow can be detrimental to the deposition process.

[0003] Accordingly, there is a need for improved control of gas flow in a processing chamber. Summary of the Invention

[0004] Embodiments of the present disclosure generally relate to gas flow in a processing chamber. More specifically, embodiments disclosed herein relate to overlapping bases and preheating rings, ventilation gaskets, and chamber pressure balance.

[0005] In at least one embodiment, a disk and gasket assembly is provided. The assembly includes a quartz disk having an outer diameter, a plurality of holes or slots formed in the quartz disk, and a quartz ring having an inner diameter less than the outer diameter of the quartz disk.

[0006] In at least one embodiment, a component for a processing chamber is provided. The component includes a base having a substrate receiving surface; a plurality of arms coupled to the base and extending from the base; a gasket radially outwardly disposed from the base and the arms and surrounding the base and the arms; a disk coupled to the arms and disposed opposite the base, the disk having a diameter; and a ring coupled to the gasket. The ring has an inner diameter, and the inner diameter of the ring is less than the diameter of the disk.

[0007] In at least one embodiment, a processing chamber is provided. The processing chamber includes a chamber body in which a susceptor is disposed. The chamber body includes an upper chamber volume defined by an upper window above a plane of the susceptor, and a lower chamber volume defined by a lower window below a plane of the susceptor. A plurality of arms are coupled to and extend from the susceptor, a gasket is disposed radially outward from the susceptor and the arms and surrounds the susceptor and the arms, and a disk is coupled to the arms and is disposed opposite the susceptor. The disk has a diameter and a ring is coupled to the gasket. The ring has an inner diameter, and the inner diameter of the ring is less than the diameter of the disk. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To enable a detailed understanding of the manner in which the above-recited features of the present disclosure are obtained, a more particular description of the disclosure briefly summarized above may be had by reference to the embodiments, some of which are illustrated in the accompanying drawings. It will be noted, however, that the drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit other equally effective embodiments.

[0009] Figure 1A is a schematic cross-sectional view of a processing chamber in accordance with at least one embodiment.

[0010] Figure 1B is Figure 1A an enlarged cross-sectional view of a portion of

[0011] Figure 1C is an enlarged cross-sectional view of a portion of Figure 1A in accordance with at least one embodiment.

[0012] Figure 1D is an enlarged cross-sectional view of a portion of Figure 1A in accordance with at least one embodiment.

[0013] Figure 2A is an isometric view of the isolation top of a lower gasket in accordance with at least one embodiment.

[0014] Figure 2B is Figure 2A a side view of the lower gasket of

[0015] Figure 3 is an enlarged cross-sectional view of different susceptor and preheat ring combinations that may be used in the Figure 1A processing chamber of

[0016] For ease of understanding, the same reference numerals have been used, where possible, to identify the same elements common to the figures. It is contemplated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further recitation. DETAILED DESCRIPTION

[0017] Embodiments of the present disclosure generally relate to gas flow in a processing chamber. More specifically, embodiments disclosed herein relate to overlapping disks and rings for controlling gas flow within a processing chamber and preventing deposition on undesired portions of the chamber.

[0018] Embodiments disclosed herein provide improved control of gas flow in a processing chamber, particularly a processing chamber having a process gas flow in an upper portion of the chamber and a purge gas flow in a lower portion of the chamber. Embodiments disclosed herein provide overlapping disks and rings that reduce or prevent gas exchange between the process gas flow in the upper portion and the purge gas flow in the lower portion compared to conventional devices where gas exchange therebetween is achieved through a gap between a susceptor and a preheat ring. The disks and rings also achieve improved heating of a substrate while preventing or substantially reducing deposition of undesired materials on a lower window of the processing chamber.

[0019] Embodiments disclosed herein reduce or prevent a purge gas flow into the upper portion of the chamber, which helps prevent dilution of the process gas flow that can be detrimental to a deposition process. Some deposition processes use a low flow rate of a primary carrier gas to maintain a high precursor partial pressure, e.g., to achieve a high dopant content during film formation. During such a process, a high purge gas flow into the upper portion dilutes the process gas flow, which may require reducing the primary carrier gas flow. Reducing the primary carrier gas flow to an undesirably low level results in poor deposition non-uniformity, including non-uniformity tuning with rotation. In addition, the purge gas flow introduces particles (e.g., metal particles) into the upper portion, which has a detrimental effect on defect performance.

[0020] Embodiments disclosed herein reduce or prevent a process gas flow into the lower portion of the chamber, which helps prevent deposition of undesired materials on surfaces in the lower portion. For example, it can prevent the process gas from contacting and causing film deposition on either or both of the back side of the susceptor or the lower window, either of which can cause a process shift, resulting in undesired changes in film thickness, dopant level, and defect formation. Preventing material deposition in the lower portion of the chamber increases tool uptime by extending the preventive maintenance intervals associated with cleaning.

[0021] Embodiments disclosed herein further provide a vent liner that enables direct venting of the purge gas flow from the lower portion of the chamber compared to conventional liners without venting where the purge gas flow is mixed with the process gas and vented from the upper portion of the chamber. In accordance with the mechanisms outlined above, direct venting of the purge gas flow from the lower portion of the chamber improves deposition process uniformity and tool uptime.

[0022] Compared to conventional processing chambers, the embodiments disclosed herein provide a dynamic pressure balance between the upper and lower portions of the chamber, where in conventional processing chambers the pressure is at least partially controlled passively based on process gas flow inputs, purge gas flow inputs, and the gap size between the susceptor and the preheat ring. According to the mechanisms outlined above, the dynamic pressure balance improves deposition process uniformity and tool uptime.

[0023] Figure 1A FIG. 4 is a schematic cross-sectional view of a processing chamber 100. The processing chamber 100 can be used to process one or more substrates 101, including depositing materials on the upper surface of the substrate 101. For example, the processing chamber 100 can be adapted to perform an epitaxial deposition process. In one example, the processing chamber 100 can be configured to process 300 mm substrates. It is contemplated that depending on the desired embodiment, the chamber 100 can operate at a low atmospheric pressure or at approximately atmospheric pressure.

[0024] The processing chamber 100 generally includes a chamber body 102, a support system 104, and a controller 106. The support system 104 can include components for monitoring and / or performing one or more processes (such as film deposition) performed using the processing chamber 100. The controller 106 (such as a programmable computer) is coupled to the support system 104 and is adapted to control the processing chamber 100 and the support system 104. The controller 106 includes a programmable central processing unit (CPU) 107, which can operate with a memory 111 (e.g., non-volatile memory) and support circuitry 113. The support circuitry 113 is conventionally coupled to the CPU 107 and includes a cache, a clock circuit, an input / output subsystem, a power supply, and the like, and combinations thereof, coupled to the various components of the processing chamber 100.

[0025] In some embodiments, the CPU 107 is one of any form of general computer processor used in an industrial setting for controlling the various monitoring system components and sub-processors, such as a programmable logic controller (PLC). The memory 111 coupled to the CPU 107 is non-transitory and is generally one or more of readily available memories, such as random access memory (RAM), read only memory (ROM), a floppy disk drive, a hard disk, or any other form of digital memory (local or remote).

[0026] In this document, the memory 111 is in the form of a computer-readable storage medium containing instructions (e.g., non-volatile memory) that, when executed by the CPU 107, facilitate the operation of the processing chamber 100. The instructions in the memory 111 are in the form of a program product, such as a program implementing the methods of the present disclosure (e.g., middleware applications, device software applications, etc.). The program code can conform to any of several different programming languages. In one example, the present disclosure can be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program of the program product defines the functions of the implementation (including the methods described herein).

[0027] Exemplary computer-readable storage media include, but are not limited to: (i) non-writable storage media on which information is permanently stored (e.g., read-only memory elements within a computer, such as a CD-ROM disk readable by a CD-ROM drive, flash memory, ROM chips, or any type of solid-state non-volatile semiconductor memory); and (ii) writable storage media on which variable information is stored (e.g., a floppy disk or a hard disk drive of a disk drive unit or any type of solid-state random-access semiconductor memory). When carrying computer-readable instructions that direct the functions of the methods described herein, such computer-readable storage media are embodiments of the present disclosure.

[0028] The chamber body 102 has an upper window 108 (e.g., a dome), a sidewall 109, and a lower window 110 (e.g., a dome) that define a processing region. A susceptor 112 for supporting the substrate 101 is disposed in the processing region. The susceptor 112 can be formed of silicon carbide or graphite coated with silicon carbide. The susceptor 112 has a substrate receiving top surface 114. The susceptor 112 is rotated and supported by support posts 116 that are coupled to respective support arms 118 extending from a shaft member 120. During operation, the substrate 101 disposed on the susceptor 112 can be raised relative to the susceptor 112 by a substrate lift arm 122 through lift pins 124.

[0029] The internal volume of the processing chamber 100 is divided into an upper chamber volume 134 (e.g., a processing gas region) above the plane of the susceptor 112 and a lower chamber volume 136 (e.g., a purge gas region) below the plane of the susceptor 112.

[0030] The processing chamber 100 includes an array of radiant heat lamps 126 for heating the backside 115 of the susceptor 112 and a preheat ring 132 (described in more detail below) and other components. Heating the susceptor 112 and the preheat ring 132 helps thermally decompose the processing gas onto the substrate 101 to form one or more layers on the substrate 101. As Figure 1AAs shown, the radiant heat lamp 126 can be disposed above the upper window 108, below the lower window 110, or both. The upper window 108 and the lower window 110 can be formed of an optically transparent material (such as quartz) to facilitate the transmission of thermal radiation therethrough.

[0031] The radiant heat lamps 126 can be arranged around the susceptor 112 in any desired manner to independently control the temperature at various regions of the substrate 101, so as to facilitate the deposition of materials onto the upper surface of the substrate 101. Although not discussed in detail herein, the deposited materials can include germanium silicon, gallium arsenide, gallium nitride, or aluminum gallium nitride, etc. The thermal energy output of each of the radiant heat lamps 126 can be precisely controlled using the controller 106. The radiant heat lamps 126 can be configured to heat the interior of the processing chamber 100 to a temperature in the range of about 200 °C to about 1600 °C.

[0032] A reflector can be placed above the upper window 108 as appropriate to reflect the infrared light radiated from the substrate 101 back onto the substrate 101. The reflector can be made of a metal, such as aluminum or stainless steel. The reflection efficiency can be improved by coating the reflector area with a highly reflective coating (such as gold coating). The reflector can be coupled to a cooling source for supplying a cooling fluid (such as water) to the reflector to cool the reflector.

[0033] The upper gasket 128 is disposed below the upper window 108 and is configured to prevent improper deposition onto chamber components, such as the sidewall 109 or the peripheral portion of the upper window 108. The upper gasket 128 is positioned adjacent to the lower gasket 130. The lower gasket 130 is configured to fit inside the inner circumference of the sidewall 109. The lower gasket 130 is disposed between the upper window 108 and the lower window 110. The lower gasket 130 radially surrounds the lower chamber volume 136. The upper gasket 128 and the lower gasket 130 can be formed of quartz.

[0034] The preheating ring 132 is coupled to the lower gasket 130 for supporting and positioning the preheating ring 132. The upper end 129 of the lower gasket 130 has a profile for receiving the preheating ring 132 thereon. As Figure 1A shown, when the susceptor 112 is in the processing position, the preheating ring 132 is configured to be disposed around the periphery of the susceptor 112. The preheating ring 132 extends radially inwardly from the lower gasket 130. As described in more detail below, the radially overlapping portion of the preheating ring 132 and the susceptor 112 is configured to reduce or prevent gas exchange between the upper chamber volume 134 and the lower chamber volume 136. The preheating ring 132 can be formed of silicon carbide. During operation, the temperature of the preheating ring 132 can be in the range of about 100 °C to about 800 °C. The heated preheating ring 132 helps to activate the processing gas flowing through the upper chamber volume 134.

[0035] The disk 151 and the ring 153 are disposed in the lower chamber volume 136 between the lower window 110 and the base 112. More specifically, the disk 151 is positioned opposite and parallel to the base 112 and extends around the arm 118 across the lower chamber volume 136. In one embodiment, the disk 151 is coupled to the arm 118 between the support shaft member 116 and a location where the arm 118 extends radially outwardly from the shaft member 120. In another embodiment, the disk 151 is coupled to the arm 118 at a height substantially the same as the location where the support shaft member 116 extends from the arm 118. The disk 151 includes a plurality of holes formed therein and is positioned to enable the lift pins 124 to extend therethrough. Similarly, the disk 151 includes a plurality of holes or slots through which the arm 118 extends. In this way, the disk 151 is coupled to the arm 118 and the disk 151 is capable of vertical movement (e.g., moving up and down within the lower chamber volume 136) and rotation about a central axis defined by the shaft member 120. In one embodiment, the disk 151 is fabricated from a single piece of material. In another embodiment, the disk 151 is fabricated from multiple pieces and arranged around the arm 118 such that the disk 151 functions substantially like a solid piece of material when installed within the lower chamber volume 136.

[0036] When the base 112 is in the raised processing position, the ring 153 is positioned within the lower chamber volume 136 adjacent to the disk 151. In one embodiment, the ring 153 is positioned at a height above any height occupied by the disk 151. The ring 153 is coupled to the lower gasket 130 and extends radially inwardly therefrom. The diameter of the disk 151 is greater than the inner diameter of the ring 153 such that the disk 151 and the ring 153 overlap one another. The outer diameter of the ring 153 is greater than the diameter of the disk 151. The overlap of the disk 151 and the ring 153 enables further control of the processing and purge gas management within the lower chamber volume 136. For example, the overlapping nature of the disk 151 and the ring 153 may prevent or substantially reduce the further travel of the processing gas through or past the overlapping portions of the preheat ring 132 and the base 112. Similarly, the purge gas introduced into the lower chamber volume 136 may be maintained below the disk 151 and the ring 153. The pressure differential above and below the overlapping disk 151 / ring 153 further prevents the processing gas from further traveling within the lower chamber volume 136 and depositing on the surfaces of the chamber (such as the lower window 110).

[0037] In one embodiment, the disk 151 and the ring 153 are made of a quartz material. In this embodiment, the quartz material is a low-OH quartz material with an OH content of less than about 30 parts per million (ppm), such as less than about 15 ppm, such as about 5 ppm or less. The transmittance of the quartz material at the desired wavelength is greater than about 90%, such as greater than about 95%, for example, greater than about 98%. In another embodiment, the disk 151 and the ring 153 are made of different materials. For example, the disk 151 is formed of a low-OH quartz material, and the ring 153 is formed of an opaque or black quartz. In this embodiment, the disk 151 will enable light to transmit through it, while the ring 153 will be used to stop light from transmitting through it. In another embodiment, the disk 151 is made of a low-OH quartz material, and the disk 151 is made of a ceramic material (such as silicon carbide or the like).

[0038] By using a quartz material for the disk 151, the heating and cooling effects on the base 112 can be reduced. For example, it is believed that the disk 151 has little or no significant effect on the heating of the base 112, and when the base 112 is in the lowered position, the cooling of the base 112 can be adjusted by adjusting the power to the radiant heat lamp 126. In addition, using a quartz material for the disk 151 enables the use of hydrochloric acid (HCl) to clean the lower window 110 by reducing the impact of HCl cleaning on throughput.

[0039] The process gas supplied from the process gas supply source 138 is introduced into the upper chamber volume 134 through the process gas inlet 140, which is formed through the sidewall 109. The process gas inlet 140 extends at least partially between the upper gasket 128 and the lower gasket 130. As indicated by the process gas flow 170, the process gas inlet 140 is configured to direct the process gas in a generally radially inward direction. During film formation, the base 112 can be located in the processing position ( Figure 1A as shown), which is adjacent to the end of the process gas inlet 140 and at approximately the same height as the end, which allows the process gas to flow under generally flat, laminar conditions along a flow path that at least partially defines the upper surface of the substrate 101. Although only one process gas inlet 140 is illustrated, the process gas inlet 140 can include two or more inlets for delivering two or more independent process gas streams having different compositions, concentrations, partial pressures, densities, and / or velocities.

[0040] The process gas exits the upper chamber volume 134 through an exhaust port (such as the process gas outlet 142), which is formed through the sidewall 109 of the process chamber 102 opposite the process gas inlet 140. The discharge of the process gas through the process gas outlet 142 is facilitated by a vacuum source (such as the vacuum pump 144), which is fluidly coupled to the downstream side of the process gas outlet 142.

[0041] Flushing gas is supplied from one or more flushing gas sources 148a and / or 148b to the lower chamber volume 136. The flushing gas sources 148a and 148b can be the same source or different sources as shown. The flushing gas can be an inert gas such as hydrogen or nitrogen. The flow of the flushing gas in the lower chamber volume 136 helps prevent or reduce the flow of the process gas or the diffusion of the process gas from the upper chamber volume 134 to the lower chamber volume 136. The flushing gas flow enters the lower chamber volume 136 through one or both of a side inlet 150 formed in or around the sidewall 109 or a bottom inlet 160 formed in the lower window 110. The side inlet 150 is provided at a height below the process gas inlet 140. A distribution channel 152 is formed radially between the lower liner 130 and the sidewall 109 and vertically between the sidewall 109 and the lower window 110. The distribution channel 152 is fluidly coupled to the side inlet 150 for receiving the flushing gas from the side inlet 150. The distribution channel 152 can extend 360° around the lower liner 130 for uniformly distributing the flushing gas around the lower chamber volume 136. The distribution channel 152 is fluidly coupled to the lower chamber volume 136 through a second channel 154. The illustrated second channel 154 is formed between the lower liner 130 and the lower window 110. The second channel 154 extends radially inwardly towards the lower end 132 of the lower liner 130. Alternatively, the second channel 154 can be formed through the body of the lower liner 130. The second channel 154 can be formed as a single annular channel or multiple arcuate channels. The second channel 154 is provided at a height below the process gas inlet 140. The illustrated second channel 154 is also provided at a height below the distribution channel 152. Alternatively, the second channel 154 can be provided at or above the distribution channel 152. As indicated by the flushing gas flow 172, the second channel 154 is configured to direct the flushing gas into the lower chamber volume 136 in a generally radially inward direction.

[0042] The upper chamber volume 134 is vertically defined above the plane of the susceptor 112 (e.g., above its substrate receiving surface 114 or above the substrate 101 disposed thereon) and above the preheating ring 132, vertically defined below the upper window 108, and radially inwardly defined from the sidewall 109. The lower chamber volume 136 is vertically defined below the plane of the susceptor 112 (e.g., below its backside 115), vertically defined above the lower window 110, and radially inwardly defined from the lower liner 130.

[0043] In the substrate loading position, the susceptor 112 is lowered relative to the preheating ring 132 to provide a vertical gap between the radially overlapping portions of the susceptor 112 and the preheating ring 132. The substrate 101 is configured to pass through the gap and through a corresponding opening in the lower liner 130 ( Figure 2Aloaded into the loading chamber body 102 and unloaded from the chamber body 102. At the processing position ( Figure 1A as shown), the susceptor 112 is raised such that the susceptor 112 and the preheating ring 132 are set at a height between the end of the processing gas inlet 140 and the end of the second channel 154.

[0044] The bottom inlet 160 is disposed between the shaft 120 and the lower window 110. The bottom inlet 160 is directly fluid-coupled to the lower chamber volume 136. The bottom inlet 160 is set at a height below the second channel 154. As indicated by the purge gas flow 174, the bottom inlet 160 is configured to direct the purge gas into the lower chamber volume 136 in a generally upward and radially outward direction. Compared to the purge gas flow 172 alone, the purge gas flow 174 from the bottom inlet 160 can be configured to increase the flow of the purge gas to the bottom of the lower chamber volume 136.

[0045] The purge gas exits the lower chamber volume 136 through an exhaust port (such as the purge gas outlet 156 formed through the sidewall 109). The shown purge gas outlet 156 is positioned opposite to the processing gas inlet 140. However, the purge gas outlet 156 can be positioned at any radial position along the sidewall 109 relative to the processing gas inlet 140. The lower liner 130 has a vent 133 (described in more detail below) for directly discharging the purge gas from the lower chamber volume 136 and discharging it into the purge gas outlet 156. Discharging the purge gas through the vent 133 and the purge gas outlet 156 is facilitated by a vacuum source (such as the vacuum pump 144), which is fluid-coupled to the downstream side of the purge gas outlet 156.

[0046] The differential pressure sensor 162 is configured to measure the pressure difference between the upper chamber volume 134 and the lower chamber volume 136. The differential pressure sensor 162 is coupled to each of the processing gas outlet 142 and the purge gas outlet 156. The shown differential pressure sensor 162 is disposed in the sidewall 109. Alternatively, the differential pressure sensor 162 can be outside the chamber body 102 and positioned adjacent to the chamber body 102, such as coupled to the sidewall 109. The measurement data from the differential pressure sensor 162 is communicated to one or both of the controller 106 and the pressure balance valve 166, which is described in more detail below.

[0047] The pressure sensor 164 is configured to measure the pressure in the upper chamber volume 134. During processing, the pressure in the upper chamber volume 134 can be from about 5 Torr to about 600 Torr. The illustrated pressure sensor 164 is external to the chamber body 102 and is positioned adjacent to and coupled to the sidewall 109. Alternatively, the pressure sensor 164 can be disposed in the sidewall 109. The illustrated pressure sensor 164 is coupled to the upper chamber volume 134 through the sidewall 109 and the upper gasket 128. Alternatively, the pressure sensor 164 can be coupled to the upper chamber volume 134 through the upper window 108 or between the upper window 108 and the sidewall 109. Measurement data from the pressure sensor 164 is communicated to one or both of the controller 106 and the pressure balance valve 166. A second pressure sensor can be configured to measure the pressure in the lower chamber volume 136. Measurement data from the second pressure sensor can be communicated to one or both of the controller 106 and the pressure balance valve 166.

[0048] The pressure balance valve 166 fluidly couples each of the process gas outlet 142 and the purge gas outlet 156 to the vacuum pump 144. The pressure balance valve 166 can be operated by the controller 106 based on data from one or both of the differential pressure sensor 162 or the pressure sensor 164. In operation, the pressure balance valve 166 adjusts the discharge of the process gas through the process gas outlet 142 and the discharge of the purge gas through the purge gas outlet 156 to adjust the pressure difference between the upper chamber volume 134 and the lower chamber volume 136. Pressure equilibrium between the upper chamber volume 134 and the lower chamber volume 136 removes the driving force for gas exchange therebetween. The process design tolerance for the pressure difference can be about ±5% or less, such as from about ±0.1% to about ±5%, such as from about ±2% to about ±5%. In one example, for a pressure of 10 Torr in the upper chamber volume 134, the lower chamber volume 136 can be maintained in the range of about 9.9 Torr to about 10.1 Torr (i.e., a tolerance of ±1%). In one example, the pressure balance valve 166 can be operated to maintain the pressure difference between the upper chamber volume 134 and the lower chamber volume 136 at about 10% or less, such as about 5% or less, such as about 1% or less.

[0049] The pressure balance valve 166 can be used to bias the pressure difference toward one of the upper chamber volume 134 or the lower chamber volume 136. In one example, the pressure balance valve 166 can be operated to maintain the lower chamber volume 136 at a pressure higher than the upper chamber volume 134. Alternatively, the pressure balance valve 166 can be operated to maintain the lower chamber volume 136 at a pressure lower than the upper chamber volume 134.

[0050] Figure 1B Yes Figure 1AAn enlarged cross-sectional view of a portion thereof. The base 112 has a raised boundary 180 that radially outwardly surrounds the substrate receiving top surface 114 of the base 112. The raised boundary 180 has a top surface 181 that faces the upper chamber volume 134. As described in more detail below, the base 112 has an externally extending flange 182 that is configured to overlap a corresponding overlapping portion of the preheating ring 132. The external flange 182 extends radially outwardly with respect to the raised boundary 180. The top surface 183 of the external flange 182 is recessed below the top surface 181 of the raised boundary 180.

[0051] The body 184 (e.g., annular body) of the preheating ring 132 has a top surface 185 that faces the upper chamber volume 134. The top surface 185 of the preheating ring 132 is coplanar with the top surface 181 of the base 112. The body 184 of the preheating ring 132 has an internally extending flange 186 that is configured to overlap the external flange 182 of the base 112. The lower surface 187 of the internal flange 186 is recessed above (below from this lower surface) the lower surface 188 of the body 184. The internal flange 186 of the preheating ring 132 is disposed above the external flange 182 of the base 112 to allow the base 112 to be lowered relative to the preheating ring 132 for substrate loading and unloading. As Figure 1B shown, the internal flange 186 of the preheating ring 132 and the external flange 182 of the base 112 are spaced apart from each other (e.g., do not contact each other). In the illustrated processing position, the vertical gap 189 between the top surface 183 of the external flange 182 of the base 112 and the lower surface 187 of the internal flange 186 of the preheating ring 132 is about 1 mm or less, such as about 0.5 mm to about 1 mm, such as about 0.6 mm to about 0.8 mm, such as about 0.6 mm. The body 184 of the preheating ring 132 has an external flange 190 that extends below the lower surface 188. As described in more detail below, the external flange 190 is configured to contact the lower gasket 130 and surround a raised portion of the lower gasket 130.

[0052] The lower gasket 130 has a top surface 191 at the upper end 129 that faces the upper chamber volume 134. The top surface 191 is coplanar with the top surface 185 of the preheating ring 132 and the top surface 181 of the base 112. The lower gasket 130 has an internally extending flange 192 that has an upper surface 193 that is configured to support the preheating ring 132 by the external flange 190. The internal flange 192 has a raised portion 194 that is configured to be radially fitted within the external flange 190 of the preheating ring 132 and is configured to help hold and center the preheating ring 132 on the lower gasket 130.

[0053] Figure 1C is a view showing the overlapping relationship between the disk 151 and the ring 153Figure 1A An enlarged cross-sectional view of a portion. In the illustrated embodiment, the outer diameter 151b of the disk 151 extends radially outward beyond the inner diameter 153b of the ring 153. Such an arrangement of the corresponding outer diameter 151b and inner diameter 153b defines an overlap magnitude 157. In one embodiment, the overlap magnitude 157 is between about 1 mm and about 100 mm. The top surface 151a of the disk 151 is adjacent to and disposed beneath the bottom surface 153a of the ring 153. A gap 161 is defined by the top surface 151a and the bottom surface 153a. The magnitude 159 of the gap 161 is about 1 mm or less, such as from about 0.5 mm to about 1 mm, such as from about 0.4 mm to about 0.8 mm, such as about 0.6 mm. Thus, the positioning of the disk 151 and the ring 153 that defines the spatial characteristics of the gap 161 serves to reduce or prevent process gas from passing through the gap 161.

[0054] The ring 153 is coupled to the lower gasket 130. In Figure 1C the illustrated embodiment, a coupling feature 155 is formed in the lower gasket 130. In this embodiment, the coupling feature 155 is a recess extending into the lower gasket 130 within which a portion of the ring 153 is installed. In this embodiment, the ring 153 is made of two or more pieces to enable simple installation within the lower gasket 130. In Figure 1D the illustrated embodiment, the coupling feature 155 is a shoulder or rim extending radially outward from the lower gasket 130, and the ring 153 rests on the coupling feature 155. In this embodiment, depending on the desired embodiment, the ring 153 is made of a single piece of material or multiple pieces of material.

[0055] Figure 2A is Figure 1A An isometric view of the isolated top of the lower gasket 130 of Figure 2B is Figure 2A A side view of the lower gasket 130 of Figure 2A and Figure 2B are thus described together herein for clarity. The lower gasket 130 generally includes an annular body 202 having a first end, or upper end 129, and an opposite second end or lower end 131 ( Figure 2B as shown). As Figure 1A shown, when the lower gasket 130 is disposed in the processing chamber 100, the first end 129 is disposed in the upper chamber volume 134, and the second end 131 is disposed in the lower chamber volume 136.

[0056] The vent 133 is formed in the body 202 of the lower gasket 130. The vent 133 includes one or more vent holes 212 that are disposed through the lower gasket 130. As shown, the one or more vent holes 212 are circular. In some other instances, the one or more vent holes may be non-circular (e.g., rounded, polygonal, in the shape of elongated slots that longitudinally extend in a circumferential or longitudinal direction relative to the lower gasket, any other suitable shape, or a combination thereof). In some instances, the same lower gasket may include a combination of different vent holes (e.g., a combination of circular holes and elongated slots). The one or more vent holes 212 shown extend radially through the sidewall 208 of the lower gasket 130. Alternatively, the one or more vent holes 212 may extend transversely through the sidewall 208 and may be parallel to each other. The lower gasket 130 shown has 14 vent holes. However, the lower gasket 130 may have any suitable number of vent holes required to discharge the purge gas from the lower chamber volume 136. The one or more vent holes 212 are circumferentially aligned around the sidewall 208 of the gasket 130. In one instance, at least one pair of the one or more vent holes 212 are in circumferential alignment. The one or more vent holes 212 are disposed within the arcuate portion of the lower gasket 130. For example, the one or more vent holes 212 may be disposed within the radial angle 214 of the gasket 130. The radial angle 214 may be about 90° or less, such as about 45° or less, such as about 30° to about 60°, such as about 45°.

[0057] The lower gasket 130 shown has eight raised portions 194 that are circumferentially disposed around the lower gasket 130 at equal intervals. However, the lower gasket 130 may have any suitable number of raised portions 194 required to help hold and center the preheat ring 132 on the lower gasket 130, as Figure 1B shown.

[0058] The lower gasket 130 includes a plurality of tabs 218 that are circumferentially disposed around the outer surface 224 of the lower gasket 130. The plurality of tabs 218 are configured to rest on the lower window 110 to provide a vertical clearance between the lower window 110 and the conical portion 226 of the lower gasket 130 for fluidly coupling the distribution channel 152 to the second channel 154, as Figure 1A shown.

[0059] The lower gasket 130 has an opening 220 in the sidewall 208 for substrate loading and unloading. The lower gasket 130 has a plurality of depressions 222 that are configured to form at least a portion of the process gas inlet 140 ( Figure 1A shown). The plurality of depressions 222 are formed in the first end 129 and the outer surface 224. The plurality of depressions 222 are fluidly coupled to each other. The plurality of depressions 222 are circumferentially disposed opposite the vent 133.

[0060] Figure 3 is an enlarged cross-sectional view of different susceptor and preheat ring combinations that can be used in the processing chamber 100 of Figure 1A . The susceptor 312 and the preheat ring 332 are similar to those shown in Figure 1B , except for the overlapping portions. Thus, the structures and corresponding markings for the non-overlapping portions are retained from Figure 1B . Compared to Figure 1B , in addition to overlapping in the vertical direction as shown in Figure 1B , the outer flange 382 of the susceptor 312 and the inner flange 386 of the preheat ring 332 overlap in the radial direction.

[0061] In Figure 3 , the outer flange 382 of the susceptor 312 has a first upper surface 383a and a second upper surface 383b that extends above the height of the first upper surface 383a. The first upper surface 383a and the second upper surface 383b shown are parallel to the plane of the susceptor 312. However, in some other instances, the first upper surface 383a and the second upper surface 383b may be positioned at an acute or obtuse angle relative to the plane of the susceptor 312. The inner surface 383c connects the first upper surface 383a and the second upper surface 383b. The inner surface 383c shown is perpendicular to the plane of the susceptor 312. However, in some other instances, the inner surface 383c may be positioned at an acute or obtuse angle relative to the plane of the susceptor 312.

[0062] Also in Figure 3 , the radially inwardly extending inner flange 386 of the preheat ring 332 has a first lower surface 387a and a second lower surface 387b that extends below the height of the first lower surface 387a. The first lower surface 387a and the second lower surface 387b shown are parallel to the plane of the preheat ring 332. However, in some other instances, the first lower surface 387a and the second lower surface 387b may be positioned at an acute or obtuse angle relative to the plane of the preheat ring 332. The outer surface 387c connects the first lower surface 387a and the second lower surface 387b. The outer surface 387c shown is perpendicular to the plane of the preheat ring 332. However, in some other instances, the outer surface 387c may be positioned at an acute or obtuse angle relative to the plane of the preheat ring 332. As shown, the profile of the inner flange 386 is shaped to conform to the profile of the outer flange 382 such that a path that further impedes gas flow is formed compared to the example shown in Figure 1B . In some instances, the gas flow path in Figure 3 may be referred to as a "zigzag path", and in some instances, additional overlapping surfaces may be included in the overlapping portions of the susceptor 312 and the preheat ring 332, thus following the same pattern or a different pattern.

[0063] Similar to Figure 1B, the first upper surface 383a and the first lower surface 387a overlap in the vertical direction, thereby forming a first vertical gap 389a therebetween, and the size of the first vertical gap can be similar to Figure 1B the vertical gap 189 in Figure 3 . In Figure 3 , additional vertical and radial gaps that impede gas flow are formed. For example, the second upper surface 383b and the first lower surface 387a overlap in the vertical direction, thereby forming a second vertical gap 389b therebetween. In addition, the second lower surface 387b and the first upper surface 383a overlap in the vertical direction, thereby forming a third vertical gap 389c therebetween. In this example, the second vertical gap 389b and the third vertical gap 389c shown are each smaller than the first vertical gap 389a. However, in some other examples, the second vertical gap 389b and the third vertical gap 389c can be of the same size or larger than the first vertical gap 389a. In this example, the second vertical gap 389b and the third vertical gap 389c shown are of the same size. However, in some other examples, the second vertical gap 389b and the third vertical gap 389c can be of different sizes. In addition, the inner surface 383c and the outer surface 387c overlap in the radial direction. In one embodiment, the second vertical gap 389b, the third vertical gap 389c, and the gap 161 (see Figure 1C and Figure 1D ) are used to regulate the flow and pressure of the process gas through the gaps 389b, 389c, 161. In this embodiment, when the magnitude of any one of the gaps 389b, 389c, 161 is changed, the magnitude of the remaining gaps also changes by the same amount. For example, if the magnitude of the gap 161 changes by 0.1 mm, the magnitudes of the gaps 389b, 389c will also change by 0.1 mm.

[0064] In some examples, the size of the radial gap formed therebetween can be larger than Figure 1B the vertical gap 189 in Figure 1B to prevent contact between the opposing surfaces. Advantageously, compared to the combination shown in Figure 3 , the pedestal and preheating ring combination shown in Figure 3 can further impede the gas flow between the chamber volumes above and below the plane of the pedestal while still allowing the pedestal to be lowered relative to the preheating ring for substrate loading and unloading.

[0065] Although the above relates to embodiments of the present disclosure, other and further embodiments of the present disclosure can be designed without departing from its basic scope, and its scope is determined by the following claims.

Claims

1. A disk and ring assembly, the assembly comprising: A quartz disk having an outer diameter; A plurality of holes or slots formed in the quartz disk; and A quartz ring having an inner diameter smaller than the outer diameter of the quartz disk.

2. The assembly of claim 1, wherein the quartz disk and the quartz ring are made of quartz material having an OH content of less than about 30 ppm.

3. The assembly of claim 2, wherein the quartz material has a transmittance greater than about 90%.

4. The assembly of claim 1, wherein the quartz disk is made of quartz material that transmits light, and the quartz ring is made of opaque quartz material.

5. The assembly of claim 1, wherein the quartz disk is made of quartz material that transmits light, and the quartz ring is made of ceramic material.

6. The assembly of claim 5, wherein the ceramic material comprises silicon carbide.

7. The assembly of claim 1, wherein the quartz disk and the quartz ring each comprise a plurality of components.

8. An assembly for a processing chamber, the assembly comprising: A base having a substrate receiving surface; A plurality of arms coupled to the base and extending from the base; A gasket disposed radially outward from the base and the arms and surrounding the base and the arms; A disk coupled to the arms and disposed opposite the base, the disk having a diameter; And A ring coupled to the gasket, the ring having an inner diameter, and the inner diameter of the ring being smaller than the diameter of the disk.

9. The assembly of claim 8, wherein the disk and the ring are arranged in an overlapping orientation.

10. The assembly of claim 9, wherein the disk and the ring are made of quartz material having an OH content of less than about 30 ppm.

11. The assembly of claim 10, wherein the quartz material has a transmittance greater than about 90%.

12. The assembly of claim 8, wherein the disk is made of quartz material that transmits light, and the ring is made of opaque quartz material.

13. The assembly of claim 8, wherein the gasket comprises a recess and the ring is coupled to the gasket within the recess.

14. The assembly of claim 8, wherein the gasket comprises a rim and the ring is coupled to the gasket on the rim.

15. A processing chamber, the processing chamber comprising: A chamber body having a base disposed therein, the chamber body comprising: An upper chamber volume defined by an upper window above a plane of the base; and A lower chamber volume defined by a lower window and below the plane of the base; A plurality of arms coupled to the base and extending from the base; A gasket disposed radially outward from the base and the arms and surrounding the base and the arms; A disk coupled to the arms and disposed opposite the base, the disk having a diameter; And A ring coupled to the gasket, the ring having an inner diameter, and the inner diameter of the ring being smaller than the diameter of the disk.

16. The processing chamber as claimed in claim 15, wherein the disk and the ring are made of a quartz material having an OH content of less than about 30 ppm.

17. The processing chamber as claimed in claim 16, wherein the quartz material has a transmittance greater than about 90%.

18. The processing chamber as claimed in claim 15, wherein a top surface of the disk and a bottom surface of the ring define a gap therebetween.

19. The processing chamber as claimed in claim 18, wherein the gap has a magnitude of less than about 1 mm.

20. The processing chamber as claimed in claim 15, wherein the ring is disposed at a height between the height of the base and the height of the disk.

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