Patent Application
20250027716
Embodiments of the present disclosure generally relate to improved reflectors for use in process chambers, such as semiconductor process chambers.
Process chambers, such as semiconductor process chambers, are often heated to high temperatures to perform different processes on substrates, such as semiconductor substrates. Many process chambers include one or reflectors positioned around the substrate (e.g., over the substrate support) to reflect energy (e.g., infrared energy) towards the substrate during processing. These reflector can help control the temperature of the substrate during the process as well as the temperature uniformity across the substrate during the process. Temperature control of the substrate and temperature uniformity can be affected by the reflector used in the process chamber. Reflectors are often replaced with different reflectors in an attempt to improve the temperature control and temperature uniformity for a given process.
When a reflector having different reflective properties is to be used the existing reflector is replaced. Replacing a reflector for a process chamber is a time consuming process that includes (1) disconnecting and removal of the existing reflector and numerous other components of the process chamber (e.g., lid, lamps, etc.) and (2) installing the new reflector and reinstalling the components that were removed and/or disconnected. This time consuming process results in significant downtime for the process chamber. Accordingly, there is an ongoing need for methods and related equipment that can reduce the amount of downtime associated with reflector replacement.
In one embodiment, a modular reflective heating system for use in a process chamber is provided. The modular reflective heating system includes: a plurality of connectors; a plurality of lamps, each lamp connected to at least one of the connectors; a reflector including: a base; and
In another embodiment, a processing system is provided comprising: a process chamber comprising: a chamber body disposed around a process volume; a substrate support in the process volume; a reflector positioned over or below the substrate support, the reflector comprising: a base; and a reflective assembly including a first plurality of reflective portions and a second plurality of reflective portions, wherein each reflective portion in the first plurality of reflective portions and the second plurality of reflective portions is connected to the base, and each reflective portion in the first plurality of reflective portions and the second plurality of reflective portions is configured to be individually disconnected from the base; and a spare reflective portion configured to replace a first reflective portion in the first plurality of reflective portions or the second plurality of reflective portions.
In another embodiment, a processing system is provided comprising: a process chamber comprising: a chamber body disposed around a process volume; a substrate support in the process volume; a plurality of lamps; a reflector positioned over or below the substrate support, the reflector comprising: a base; and a reflective assembly including a first plurality of reflective portions and a second plurality of reflective portions, wherein the plurality of lamps are positioned between the substrate support and the reflector, each reflective portion in the first plurality of reflective portions and the second plurality of reflective portions is connected to the base, and each reflective portion in the first plurality of reflective portions and the second plurality of reflective portions is configured to be individually disconnected from the base; and a spare reflective portion configured to replace a first reflective portion in the first plurality of reflective portions or the second plurality of reflective portions, wherein the spare reflective portion has a reflective surface configured to face one of the lamps when the spare reflective portion is coupled to the base, and the reflective surface on the spare reflective portion has a different radius of curvature, a different size, or a different coating than corresponding reflective surface on the first reflective portion.
So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
Embodiments of the present disclosure generally relate to improved reflectors for use in process chambers, such as semiconductor process chambers. The improved reflectors have a modular design allowing one or more reflective portions of a reflector to be easily replaced with one or different reflective portions that can alter the thermal performance of the reflector while the other portions of the reflector remain installed. For example, a reflective portion of a reflector can be replaced with a new portion that has a different reflecting surface (e.g., a different coating or a different radius curvature) or a different set of internal cooling channels to allow the thermal performance of the reflector to be improved without removing the entire reflector.
The process chamber 101 includes a chamber body 102 that includes a top 103, a bottom 104, and one or more sides 105. In some embodiments, the chamber body 102 can be made of a process resistant material, such as aluminum or stainless steel, for example 316L stainless steel. The chamber body 102 is disposed around structural components of the processing chamber 101, such as an upper window 106U, a lower window 106L, an inner liner 136, and an outer line 137. The liners 136, 137 can be positioned between the windows 106U, 106L and the chamber body 102 to insulate the windows 106U, 106L from the chamber body 102. The windows 106U, 106L and the liners 136, 137 enclose an interior volume 110 (also referred to as process volume) of the process chamber 101. In one embodiment, the windows 106U, 106L can each be formed of quartz.
The process chamber 101 includes an upper reflector 200U positioned between the upper window 106U and the top 103 of the chamber body 102. The process chamber 101 further includes a lower reflector 200L positioned between the lower window 106L and the bottom 104 of the chamber body 102. The reflectors 200U, 200L assist in heating the substrate during processing and maintaining temperature uniformity of the substrate during processing. Additional details on the reflectors 200U, 200L are provided below.
The process chamber 101 further includes a substrate support assembly 116. The substrate support assembly 116 can include supports 117 and a shaft 118 that is connected to the supports 117. A susceptor 115 can be positioned on the supports 117. The process chamber 101 can further include an actuator 119 that is coupled to the shaft 118 of the substrate support assembly 116. The actuator 119 is configured to rotate the shaft 118 and the susceptor 115 about a central vertical axis C extending through a center of the shaft 118 and the susceptor 115. A substrate 50 can be positioned on the susceptor 115 during processing, such as during an epitaxial deposition.
Gases can be provided to the interior volume 110 from the gas sources 140 during depositions or other processes. These gases can be exhausted from the interior volume 110 by the exhaust pump 145. The process chamber 101 can further include a preheat ring 114 that can be positioned around the susceptor 115. In some embodiments, purge gas (not shown) can be provided below the susceptor 115 to assist in preventing process gases from reaching areas in the process chamber 101 below the susceptor 115 and causing unintended deposits.
The process chamber 101 can further include a plurality of upper lamps 220U and a plurality of lower lamp 220L for heating of the substrate 50 and components in the interior volume 110, such as the susceptor 115. The upper lamps 220U are positioned between the upper window 106U and the upper reflector 200U. The lower lamps 220L are positioned between the lower window 106L and the lower reflector 200L. In one embodiment, the upper lamps 220U and the lower lamp 220L are infrared (IR) lamps.
Simplified versions of the reflectors 200U, 200L and the lamps 220U, 220L are shown in
The upper reflective assembly 210U is positioned between the upper lamps 220U and the upper base 250U. The upper reflective assembly 210U includes a plurality of reflective portions 211-214 (see
Similarly, the lower reflector 200L includes a lower base 250L and a lower reflective assembly 210L coupled (e.g., fastened) to the lower base 250L. The lower base 250L and the lower reflective assembly 210 can each surround the shaft 118. Supports (not shown) can be used to support the lower reflector 200L below the lower window 106L in the process chamber 101. The lower reflective assembly 210L is positioned between the lower lamps 220L and the lower base 250L. The lower reflective assembly 210L includes a plurality of reflective portions 211-214 (see
In some embodiments, the reflective portions of the reflective assemblies 210U, 210L can be formed of gold, alumina, or another metal or alloy that is coated with gold or alumina, so that the reflecting surface is formed of gold or alumina. In some embodiments, the bottom surface of the upper base 250U and the upper surface of the lower base 250L can be coated with alumina to reflect any radiation from the lamps that reaches these surfaces. The lower base 250L can be fluidly coupled to the lower cooling sources 190L. In one embodiment, the lower cooling sources 190U can include a cooling water source and a cooling air source. Cooling water and cooling air from the lower cooling sources 190L can be provided to or circulated through the lower base 250L during processing to assist in maintaining a temperature setpoint for the lower reflector 200L as well as for assisting in maintaining temperature uniformity across the lower reflector 200L during processing.
As described in further detail below each reflective portion 211-214 in the upper reflective assembly 210U (
The process chamber 101 can further include a plurality of upper temperature sensors 290U and a plurality of lower temperature sensors 290L. The plurality of upper temperature sensors 290U can be positioned over the upper reflector 200U and can be configured to monitor the temperature of different portions of the substrate 50 and/or susceptor 115 during processing. Similarly, the plurality of lower temperature sensors 290L can be positioned below the lower reflector 200L and can be configured to monitor the temperature of different portions of the substrate 50 and/or susceptor 115 during processing. In one embodiment, the temperatures sensors 290U, 290L can each be pyrometers. The temperatures sensors 290U, 290L can be connected to the controller 155. The controller 155 can use the measurements from the temperature sensors 290U, 290L to control the power provided to the corresponding lamps 220U, 220L during processing, which can be used to control the temperature of different portions of the substrate 50 during processing.
The processing system 100 also includes the controller 155 for controlling processes performed by the processing system 100. The controller 155 can be any type of controller used in an industrial setting, such as a programmable logic controller (PLC). The controller 155 includes a processor 157, a memory 156, and input/output (I/O) circuits 158. The controller 155 can further include one or more of the following components (not shown), such as one or more power supplies, clocks, communication components (e.g., network interface card), and user interfaces typically found in controllers for semiconductor equipment.
The memory 156 can include non-transitory memory. The non-transitory memory can be used to store the programs and settings described below. The memory 156 can include one or more readily available types of memory, such as read only memory (ROM) (e.g., electrically erasable programmable read-only memory (EEPROM), flash memory, floppy disk, hard disk, or random access memory (RAM) (e.g., non-volatile random access memory (NVRAM).
The processor 157 is configured to execute various programs stored in the memory 156, such as epitaxial deposition processes and other processes (e.g., cleaning processes). During execution of these programs, the controller 155 can communicate to I/O devices through the I/O circuits 158. For example, during execution of these programs and communication through the I/O circuits 158, the controller 155 can control outputs, such as the power provided to the lamps 220U, 220L for heating the components in the interior volume 110 as well as the position of valves and/or the speed of pumps for controlling the flowrate of cooling water or cooling gas through the reflectors 200U, 200L. The memory 156 can further include various operational settings used to control the processing system 100. For example, the settings can include temperature setpoints for the substrate 50 and/or susceptor 115 during different processes.
The upper reflector 200U includes the upper reflective assembly 210U that is coupled (e.g., fastened) to the upper base 250U. The upper reflective assembly 210U includes a plurality of reflective portions 211-214 arranged in a plurality of zones 201-204. The plurality of zones 201-204 include a first zone 201, a second zone 202, a third zone 203, and a fourth zone 204.
The first zone 201 can include a first plurality of four reflective portions 211A-211D that form a central section of the upper reflective assembly 210U. In some embodiments, the first zone 201 can have a circular shape, elliptical shape, rectangular shape, diamond shape, or an irregular shape. Each reflective portion 211A-211D can be positioned at a different angular location around a center C of the upper reflective assembly 210U. For example, each reflective portion 211A-211D is shown occupying a different quadrant around the center C of the upper reflective assembly 210U.
The second zone 202 can be a ring-shaped zone positioned between the first zone 211 and the third zone 213. The second zone 202 includes a second plurality of six reflective portions 212A-212F arranged in a ring-shaped pattern around the first zone 201. The first plurality of reflective portions 211A-211D are positioned inside the ring-shaped pattern of the second plurality of reflective portions 212A-212F. Used herein, ring-shaped includes rings having a circular, elliptical, polygonal shaped rings, or any combination thereof. The reflective portions and lamps described herein can be arranged in ring-shaped patterns.
The third zone 203 can be a ring-shaped zone positioned between the second zone 202 and the fourth zone 204. The third zone 203 includes a third plurality of eight reflective portions 213A-213H arranged in a ring-shaped pattern around the second zone 202.
The fourth zone 204 can be a ring-shaped zone positioned as an outermost zone around the third zone 203. The third zone 203 includes a fourth plurality of ten reflective portions 213A-213J arranged in a ring-shaped pattern around the third zone 203.
With reference to the reflective portion 214B, each reflective portion 211- 214 can include a first opening 231 and a second opening 232. With reference to reflective portion 214A, a first connector 221 extends into the first opening 231 to make a first connection (e.g., power connection) with one of the upper lamps 220U. Similarly, a second connector 222 extends into the second opening 232 of the reflective portion 214A to make a second connection (e.g., ground connection) with one of the upper lamps 220U. In some embodiments, the openings 231, 232 can extend to an edge of the corresponding reflective portion 211-214 and line up with an opening of a neighboring reflective portion 211-214, so that a larger opening is formed by the alignment of the openings of the two neighboring reflective portions 211-214. The connectors 221, 222 can extend through openings in the base 250U and the reflective assembly 210U. Although two connectors 221, 222 are shown for the lamp 220U, in some embodiments, a single connector, such as a single connector providing a power and ground connection, can extend through a corresponding single hole in the base and reflective assembly.
Although only one lamp 220U and one set of connectors 221, 222 are shown in
The upper reflective assembly 210U further includes a slot 230U extending radially outward from a location at or near the center C of the upper reflective assembly 210U in the first zone 201 to a location in the third zone 203. The slot 230U is an opening that is positioned to allow the upper temperature sensors 290U to perform temperature measurements on the substrate 50 and/or susceptor 115 during processing.
With reference to reflective portion 211D, each reflective portion 211-214 can further include a plurality of cooling holes 241 for cooling the corresponding reflective portion 211-214 and a plurality of fastener holes 242 for mounting the corresponding reflective portion 211-214 to the upper base 250U. In some embodiments each reflective portion 211-214 can include a plurality, such as ten or more cooling holes 241 and a plurality, such as ten or more fastener holes 242. Only one cooling hole 241 and one fastener hole 242 are shown in order to not clutter the drawing. Cooling air from the cooling sources 190U can be directed through the plurality of cooling holes 241 during processing to cool the reflective portions 211-214.
The upper base 250U can include a first plurality of openings 253 and a second plurality of openings 254. Each opening 253 in the first plurality of openings 253 is positioned to align with one of the first openings 231 of the upper reflective assembly 210U when the upper reflective assembly 210 (
The upper base 250U can further include a plurality of cooling holes 281 to assist with directing cooling gas from the upper cooling sources 190U to the reflective portions 211-214 of the upper reflective assembly 210U. Each cooling hole 281 is positioned to align with one of the cooling holes 241 on one of the reflective portions 211-214 of the upper reflective assembly 210 when the upper reflective assembly 210 is mounted (
The upper base 250U can further include plurality of fastener holes 282 (e.g., threaded holes) for mounting the corresponding reflective portions 211-214 to the upper base 250U. Each fastener hole 282 is positioned to align with one of the fastener holes 242 on one of the reflective portions 211-214 of the upper reflective assembly 210 when the upper reflective assembly 210 (
The upper base 250U can further include a cooling channel 260 configured to cool the upper base 250 and reflective assembly 210U. The cooling channel 260 can extend through an interior of the inner body 251U of the upper base 250U. The cooling channel 260 includes an inlet 261, an outlet 262, and an inner channel 263 extending through the interior of the inner body 251U of the upper base 250U from the inlet 261 to the outlet 262. Cooling water or another coolant from the upper cooling sources 190U can be directed through the cooling channel 260 during processing to assist in preventing the upper reflector 200U from overheating during processing. Although the cooling channel 260 is shown as a single arc at one radial location relative to the center C of the upper base 250U, in some embodiments the cooling channel 260 can extend through more locations of the interior of the inner body 251U, such as to locations closer to the center C of the upper base 250U. Although not shown, in some embodiments, the cooling channel 260 can be configured with a plurality of inlets and outlets along the inner channel 263 that align with inlets and outlets on corresponding reflective portions 211-214, so that cooling fluid can be circulated through each of the reflective portions 211-214 during processing.
The upper base 250U can further include a slot 270U that is configured to align with the slot 230U (see
The lower reflector 200L includes the lower reflective assembly 210L that is coupled (e.g., fastened) to the lower base 250L. The differences between the upper base 250U (
The inner body 251L of the lower base 250L is the same as the inner body 251U of the upper base 250U (
As shown in
The reflective portion 214H has a height H1 in the vertical direction that corresponds to a length of the first side 301 and the second side 302. The reflective portion 214H has a width W1 in a horizontal direction that corresponds to the distance between the first side 301 and the second side 302. The reflective surface 304 of the reflective portion 214H is spaced apart from the lamp 220U by a first distance D1. The reflective surface 304 can be a curved surface with a radius of curvature RC1. The reflective portion 214H can further include a first cooling hole 241A and a second cooling hole 241B for directing cooling gas through the holes 241A, 241B during processing. The reflective surface 304 can be formed by a coating C1 (e.g., a coating of gold or alumina having a first thickness).
The spare reflective portion 215S has different reflective properties compared to the reflective portion 214H. Replacing the reflective portion 214H with the spare reflective portion 215S can be done to modify the intensity of radiation received across different portions of the substrate (e.g., near the edge of the substrate) during processing.
The spare reflective portion 215S has a height H2 in the vertical direction that is shorter than the height H1 of the reflective portion 214H described above. This reduced height H2 spaces the spare reflective portion 215S from the lamp 220U by a distance D2 when the spare reflective portion 215S is mounted to the base 250U. This distance D2 is greater than the distance D1 described above for distance between the reflective portion 214H and the lamp 220U. Although the spare reflective portion 215S has the same width W1 as the reflective portion 214H, in some embodiments the width of the reflective portion can also be changed when a reflective portion is replaced with another reflective portion.
The reflective surface 304 on the spare reflective portion 215S has a radius of curvature RC2 that is larger than the radius of curvature RC1 of the reflective surface 304 of the reflective portion 214H described above. The reflective surface 304 on the spare reflective portion 215S can be formed by a coating C2 that is different (e.g., different material, different thickness) than the coating C1 of the reflective surface 304 of the reflective portion 214H described above. Furthermore, the material (e.g., copper) that forms the body of the spare reflective portion 215S can also be different than the material (e.g., gold) that forms the body of the reflective portion 214H. The spare reflective portion 215S can further include a first cooling hole 341A and a second cooling hole 341B for directing cooling gas through the holes 341A, 341B during processing. The cooling holes 341A, 341B are larger than the corresponding cooling holes 241A, 241B described above for the reflective portion 214H. Furthermore, the cooling holes 341A, 341B are positioned closer to the sides 301, 302 of the spare reflective portion 215S than the cooling holes 241A, 241B are positioned to the sides 301, 302 of the reflective portion 214H.
Overall, the spare reflective portion 215S has a different size (e.g., height H2 is less than height H1), a different shape (radius of curvature RC2 is greater than radius of curvature RC1), a different coating (coating C2 instead of coating C1), is a different distance from the lamp 220 (distance D2 instead of D1), and includes a different cooling configuration (holes 341A, 341B instead of holes 241A, 241B) relative to the reflective portion 214H described above. Each one of these differences can individually be sufficient to substantially modify the reflective properties of a spare reflective portion compared to an existing reflective portion that is already installed. Although not shown, the reflective portions 214H, 215S can include the same set of fastener holes 242 (see
Although
Furthermore, the modular reflector systems in this disclosure can also allow for the position of one or more reflective portions to be switched with the position of another reflective portion to see if an improvement in process uniformity can be achieved by the switching of the positions of the reflective portions. For example, with reference to
While the foregoing is directed to examples of the present disclosure, other and further examples of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
