Exhaust passage body, exhaust system, and process system applicable for semiconductor substrate processing

Abstract

This document describes a method and apparatus for processing a semiconductor substrate. The apparatus includes one or more growth monitors disposed within an exhaust system of a deposition chamber. These growth monitors are quartz crystal film thickness monitors and are configured to measure the film thickness grown on the monitors during substrate processing within the deposition chamber. The growth monitors are connected to a controller that adjusts heating and airflow settings during processing operations. Measurements from the growth monitors and other sensors within the deposition chamber are used to adjust the processing chamber model of the deposition chamber as the substrate is processed.

Description

[Technical Field]

[0001] The embodiments of this disclosure generally relate to apparatus and methods for manufacturing semiconductor devices. More specifically, the apparatus disclosed herein relates to an exhaust assembly and a growth rate sensor within a semiconductor process chamber. Methods of using the apparatus are also disclosed. [Previous Technology]

[0002] Semiconductor substrates are processed for a variety of applications, including the manufacture of integrated devices and micro-devices. During processing, the substrate is positioned on a pedestal within a process chamber. The pedestal is supported by a support shaft that can rotate about a central axis. Precise control of the heat source is preferred to uniformly heat the substrate within tight tolerances. The temperature of the substrate affects the uniformity of the material deposited on it.

[0003] The ability to precisely control substrate temperature within a process chamber has a significant impact on throughput and yield. Conventional process chambers struggle to meet the temperature control standards required for manufacturing next-generation devices, while simultaneously meeting the growing demand for higher throughput and faster production rates. Process gases flow through the process volume within the process chamber. The process gases flow parallel to the substrate surface from one side of the process chamber to the opposite side. Heating and gas flow within the process chamber can be adjusted to improve the film deposition rate across the substrate. Current sensors within the process chamber have limited resolution, and adding additional sensors increases downtime and ownership costs. Substrates processed between calibration and measurement operations also exhibit less precise deposition rates due to variations in chamber conditions. Current sensors within the process chamber include pyrometers, but pyrometers have limited resolution. Downstream pressure sensors cannot provide sufficient partial pressure estimates in other parts of the process chamber.

[0004] Therefore, improvements to the exhaust system and growth rate monitoring are needed. [Summary of the Invention]

[0005] This disclosure generally relates to process chambers for semiconductor processing. In one embodiment, an exhaust channel body for substrate processing is described. The exhaust channel body includes a first exhaust chamber, a first exhaust inlet opening, a first plurality of fins, a first exhaust outlet opening, a first baffle, and at least one growth monitor. The first exhaust chamber is formed through a first end of the exhaust channel body and is fluidly connected to the first exhaust chamber. The first plurality of fins are disposed adjacent to the first exhaust inlet opening within the first exhaust chamber. The first exhaust outlet opening is formed through a second end of the exhaust channel body and is fluidly connected to the first exhaust chamber. The first baffle is disposed adjacent to the first exhaust outlet opening and configured to narrow the width of the first exhaust chamber. The at least one growth monitor is disposed downstream of the first baffle and configured to measure the thickness of material deposited on the growth monitor.

[0006] In another embodiment, an exhaust system for substrate processing is described. This exhaust system includes an exhaust channel body, an exhaust chamber, an exhaust inlet opening, a plurality of fins, an exhaust outlet opening, at least one baffle, and at least one growth monitor. The exhaust inlet opening is formed through a first end of the exhaust channel body and has an inlet width. The exhaust inlet opening is configured to fluidly connect the exhaust chamber and a process volume. The fins are disposed adjacent to the exhaust inlet opening within the exhaust chamber. The exhaust outlet opening is formed through a second end of the exhaust channel body and is fluidly connected to the exhaust chamber. The at least one baffle is disposed adjacent to the exhaust outlet opening and configured to narrow the width of the exhaust chamber to an outlet width smaller than the inlet width. The at least one growth monitor is disposed downstream of the baffle and configured to measure the thickness of material deposited on the growth monitor. An exhaust collector is coupled to the exhaust channel body at the exhaust outlet.

[0007] In another embodiment, a processing system for substrate processing is described. This processing system includes a chamber body forming a process volume, a substrate support disposed within the process volume of the chamber body, an upper window disposed above the substrate support, and a lower window disposed below the substrate support. Each of the upper and lower windows further defines the process volume. An injector is disposed through one side of the chamber body and configured to introduce process gas into the process volume. An exhaust system is disposed through a second side of the chamber body opposite the injector. The exhaust system includes an exhaust channel body, an exhaust chamber disposed through the exhaust channel body, an exhaust inlet opening, a plurality of fins, an exhaust outlet opening, at least one baffle, and at least one growth monitor. The exhaust inlet opening is formed through a first end of the exhaust channel body. The exhaust inlet opening is configured to fluidly connect the exhaust chamber and the process volume. The fins are disposed within the exhaust chamber. The exhaust outlet opening is formed through a second end of the exhaust channel body and fluidly connected to the exhaust chamber. At least one baffle is disposed downstream of the fins and configured to narrow the width of the exhaust chamber to an outlet width smaller than the inlet width. At least one growth monitor is disposed downstream of the baffle and configured to measure the thickness of the material deposited on the growth monitor.

Implementation Method

[0017] This disclosure relates to an exhaust assembly and a growth rate sensor within a semiconductor process chamber. The growth rate sensor is a quartz crystal film thickness monitor, and is equipped to measure the film thickness on the growth rate sensor. The film thickness on the growth rate sensor is equivalent to the growth rate on the substrate within the process chamber. Subsequently, thickness measurement can be used to adjust one or more process controls within the process volume of the process chamber and improve cross-substrate film growth.

[0018] Quartz crystal monitors without additional protection may react with epitaxial deposition process chemicals. Therefore, quartz crystal monitors as described herein are configured to reduce reactions with epitaxial deposition process chemicals, which could negatively impact sensor performance, sensor lifespan, or process conditions within the process chamber. Coating the quartz crystal in the quartz crystal monitor reduces the reaction between the quartz crystal and process chemicals. Similarly, using gold-containing contacts within the quartz crystal monitor reduces the chemical interaction between the sensor head metal and process chemicals.

[0019] The location and number of quartz crystal monitors provide increased sensitivity and sensor lifespan. The configuration of the exhaust system around the quartz crystal monitors further enables consistent or minimal flow impact within the process volume, while increasing the process gas flow rate across the quartz crystal monitors to improve growth rate on the monitors. Therefore, the exhaust system may include a configuration of fins and baffles to control the gas flow rate. The fins, baffles, and other components of the exhaust system may further be formed or coated with a material to increase heat retention of the process gas as it flows through the exhaust system. This makes film growth on the quartz crystal monitors more predictable and enhanced.

[0020] The software algorithm in the process chamber controller obtains the growth rate measurement value from the quartz crystal monitor and enables the calibration of other sensors in the process chamber and the processing conditions in the process chamber to improve the film thickness growth rate.

[0021] Figure 1 is a schematic diagram of a deposition chamber 100 according to an embodiment of the present disclosure. The deposition chamber 100 is an epitaxial deposition chamber. The deposition chamber 100 is used to grow an epitaxial film on a substrate (e.g., substrate 102). The deposition chamber 100 generates a precursor crossflow across the top surface 150 of the substrate 102.

[0022] The deposition chamber 100 includes an upper body 156, a lower body 148 disposed below the upper body 156, and a flow module 112 disposed between the upper body 156 and the lower body 148. The upper body 156, the flow module 112, and the lower body 148 form the chamber body. A substrate support 106, an upper window 108, a lower window 110, a plurality of upper lamps 141, and a plurality of lower lamps 143 are disposed within the chamber body. As shown, a controller 120 is communicated with the deposition chamber 100 and is used to control processes, such as those described herein. The substrate support 106 is disposed between the upper window 108 and the lower window 110. The upper lamps 141 are disposed between the upper window 108 and the cover 154. The upper lamps 141 form part of the upper lamp module 155. The cover 154 may include a plurality of sensors (not shown) disposed therein for measuring the temperature within the deposition chamber 100. These lower lights 143 are positioned between the lower window 110 and the floor 152. These lower lights 143 form part of the lower light module 145. The upper window 108 is an upper dome and is formed of an energy transmission material such as quartz. The lower window 110 is a lower dome and is formed of an energy transmission material such as quartz.

[0023] A process volume 136 is formed between an upper window 108 and a lower window 110. The process volume 136 has a substrate support 106 disposed therein. The substrate support 106 includes a top surface on which a substrate 102 is disposed. The substrate support 106 is attached to a shaft 118. This shaft is connected to a motion assembly 121. This motion assembly 121 includes one or more actuators and / or adjustment devices that provide movement and / or adjustment of the shaft 118 and / or the substrate support 106 within the process volume 136.

[0024] The substrate support 106 may include a lifting pin hole 107 disposed therein. The lifting pin hole 107 is sized to receive a lifting pin 132 for lifting the substrate 102 from the substrate support 106 before or after the deposition process. When the substrate support 106 descends from the process position to the transfer position, the lifting pin 132 may rest on the lifting pin stop 134.

[0025] The flow module 112 includes a plurality of process gas inlets 114, a plurality of purge gas inlets 164, and one or more exhaust gas outlets 116. The process gas inlets 114 and the purge gas inlets 164 are disposed on the side of the flow module 112 opposite to the one or more exhaust gas outlets 116. One or more flow deflectors are disposed below the process gas inlets 114 and the one or more exhaust gas outlets 116. The flow deflectors are disposed above the purge gas inlets 164. A gasket 163 is disposed on the inner surface of the flow module 112 and protects the flow module 112 from the reactive gases used during the deposition process. The process gas inlets 114 and the purge gas inlets 164 are positioned to allow gas to flow parallel to the top surface 150 of the substrate 102 disposed within the process volume 136. The process gas inlets 114 are fluidly connected to the process gas source 151. The purge gas inlets 164 are fluidly connected to the purge gas source 162. One or more exhaust gas outlets 116 are fluidly connected to exhaust pump 157.

[0026] One or more exhaust gas outlets 116 are further connected to or include an exhaust system 178. The exhaust system 178 is fluidly connected to one or more exhaust gas outlets 116 and an exhaust pump 157. As described herein, the exhaust system 178 includes one or more growth monitors 310 (Figure 3A) and is configured to facilitate controlled deposition of layers on the substrate 102.

[0027] Figure 2 shows a cross-sectional plan view of the deposition chamber 100 of Figure 1 according to an embodiment of the present disclosure. The deposition chamber 100 includes an injector 202 disposed across an exhaust system 178. The injector 202 includes a process gas inlet 114 and is fluidly coupled to a process gas source 151. The injector 202 may be configured to pass through at least a portion of the flow module 112 or may be part of the flow module 112. The exhaust system 178 is disposed on the side of the process volume 136 opposite to the injector 202. The exhaust system 178 is formed via the flow module, attached to the flow module, or is part of the flow module.

[0028] The exhaust system 178 further includes at least one exhaust passage body 204a, 204b. The exhaust passage bodies 204a, 204b form an exhaust path for the gas exiting the process volume 136 before entering the exhaust collector 206. As shown in Figure 2, there is a first exhaust passage body 204a and a second exhaust passage body 204b. The first exhaust passage body 204a and the second exhaust passage body 204b are mirror images and may be similar in size and configuration. In other embodiments, there may be more or fewer exhaust passage bodies 204a, 204b. In some embodiments, only one exhaust passage body exists, such that two exhaust passage bodies 204a, 204b are combined into a single body. In still other embodiments, three or more exhaust passage bodies may exist, such as three exhaust passage bodies 204a, 204b. The size and configuration of the exhaust passage bodies 204a, 204b may vary depending on the size and operation of the deposition chamber 100.

[0029] Both the first exhaust passage body 204a and the second exhaust passage body 204b are coupled to the exhaust collector 206 at the end of the exhaust passage bodies 204a and 204b opposite to the process volume 136. The exhaust collector 206 is configured to collect exhaust from the first exhaust passage body 204a and the second exhaust passage body 204b. As the exhaust collector 206 extends away from the exhaust passage bodies 204a and 204b, the exhaust collector 206 narrows.

[0030] Figure 3A shows a cross-sectional plan view of the exhaust system 178 of the deposition chamber 100 of Figure 1 according to an embodiment of this disclosure. The exhaust system 178 is configured to control the exhaust flow leaving the process volume 136 before flowing through one or more growth monitors 310. The increased flow rate at the growth monitors 310 relative to the flow rate at the inlet of the exhaust channel bodies 204a, 204b enhances film growth on the growth monitors 310. Therefore, the width of each exhaust channel body 204a, 204b narrows from the inlet width W1 to the outlet width W2 to increase the flow rate. The fin array 314 and one or more baffles 304 are positioned within each exhaust channel body 204a, 204b to enable the narrowing of the exhaust channel bodies 204a, 204b while reducing the impact of the narrowing on the flow path of the process gas through the process volume 136.

[0031] As the process gas flows out of the process volume 136 and into the exhaust system 178, the process gas flows in the first flow path 318. The first flow path 318 is mainly parallel to the top surface 150 of the substrate 102 and the gas flows out of the injector 202. The process gas flows into the exhaust system 178 through exhaust inlet openings 305a and 305b, which are configured to pass through each exhaust channel body 204a and 204b. Therefore, the first exhaust inlet opening 305a is configured to pass through the first end of the first exhaust channel body 204a, and the second exhaust inlet opening 305b is configured to pass through the first end of the second exhaust channel body 204b. The exhaust inlet openings 305a and 205b are in fluid communication with the exhaust chambers 312a and 312b. The exhaust chambers 312a and 312b are disposed within each exhaust channel body 204a and 204b. Therefore, the first exhaust chamber 312a is disposed within the first exhaust channel body 204a, and the second exhaust chamber 312b is disposed within the second exhaust channel body 204b. The first exhaust inlet opening 305a is in fluid communication with the first exhaust chamber 312a, and the second exhaust inlet opening 305b is in fluid communication with the second exhaust chamber 312b.

[0032] Each exhaust inlet opening 305a, 305b has an inlet width W1. The inlet width W1 is approximately 10 mm to approximately 210 mm, such as approximately 45 mm to approximately 210 mm, such as approximately 75 mm to approximately 175 mm, such as approximately 100 mm to approximately 155 mm. Therefore, the inlet width W1 is less than or equal to half the width of the process volume 136.

[0033] Exhaust outlet openings 308a and 308b are disposed on the side of the exhaust passage bodies 204a and 204b opposite to the exhaust inlet openings 305a and 305b. Therefore, the first exhaust outlet opening 308a is disposed on the second side of the first exhaust passage body 204a opposite to the first side and is in fluid communication with the first exhaust chamber 312a. The second exhaust outlet opening 308b is disposed on the second side of the second exhaust passage body 204b opposite to the first side and is in fluid communication with the second exhaust chamber 312b. The width of the exhaust outlet openings 308a and 308b is smaller than the width of the exhaust inlet openings 305a and 305b. The exhaust outlet openings 308a and 308b have an outlet width W2 of approximately 15 mm to approximately 110 mm, such as approximately 20 mm to approximately 100 mm, such as approximately 20 mm to approximately 40 mm. The outlet width W2 is smaller than the inlet width W1, allowing a higher concentration of process gas to flow through the growth monitor 310.

[0034] The ratio of inlet width W1 to outlet width W2 is approximately 2:1 to approximately 20:1, such as approximately 3:1 to approximately 10:1, such as approximately 4:1 to approximately 8:1. The ratio of inlet width W1 to outlet width W2 enables good film growth on the growth monitor 310, while reducing the impact of the reduced outlet width W2 on back pressure and flow path through process volume 136.

[0035] The process gas flowing through the deposition chamber 100 enters the exhaust channel bodies 204a and 204b through exhaust inlet openings 305a and 305b. Simultaneously, in the first flow path 318, one or more baffles 304 narrow the exhaust chambers 312a and 312b to an outlet width W2 adjacent to the exhaust outlet openings 308a and 308b, thus becoming the second flow path 320. The second flow path 320 directs the process gas towards the centerline C of the exhaust system and to one side of the exhaust chambers 312a and 312b, such as the inner side of the exhaust chambers 312a and 312b. Once the process gas passes through the exhaust outlet openings 308a and 308b, the path of the process gas becomes the third flow path 322. The third flow path 322 is a condensation flow path. The third flow path 322 passes through the collector chamber 316. The collector chamber 316 is a chamber located within the exhaust collector 206.

[0036] A fin array 314 disposed within each exhaust channel body 204a, 204b is configured to maintain a first flow path 318 through at least a portion of the exhaust chambers 312a, 312b. The fin array 314 includes a plurality of fins 302, such that a first plurality of fins 302 are disposed within a first exhaust chamber 312a of the first exhaust channel body 204a. Each of the first plurality of fins 302 extends from a first exhaust inlet opening 305a toward a first exhaust outlet opening 308a. A second plurality of fins 302 are disposed within a second exhaust chamber 312b and a second exhaust channel body 204b. Each of the second plurality of fins 302 extends from a second exhaust inlet opening 305b toward a second exhaust outlet opening 308b. The fin array 314 is configured to maintain good flow control through the process volume 136 and extends from a position adjacent to the exhaust inlet openings 305a, 305b.

[0037] The number of fins 302 within the fin array 314 may be at least two fins 302, such as at least four fins 302, such as at least five fins 302, such as five fins 302 to about 30 fins 302, such as five fins 302 to about 20 fins 302. The number of fins 302 helps to create a smaller gap between each adjacent fin 302 and control the first flow path 318.

[0038] One or more growth monitors 310 are disposed within the fin array 314, such as between two adjacent fins 302. Two or more growth monitors 310 may be disposed within each fin array 314 of both the first exhaust channel body 204a and the second exhaust channel body 204b. The growth monitors 310 within the fin array 314 can help provide measurements of the growth rate at different radial locations on the substrate 102.

[0039] Each fin 302 within the fin array 314 is parallel to each other. The fins 302 extend in a direction parallel to the desired first flow path 318 and parallel to the gas exiting the injector 202. Other configurations of the fin array 314 are considered. In some embodiments, each fin 302 has a similar length. In other embodiments, each of the fins 302 may not necessarily have the same length, such that the fins 302 closer to the centerline C of the process volume 136 and the exhaust system 178 are shorter than the fins 302 farther from the centerline C.

[0040] Once the process gas leaves the fin array 314, it flows into the main portion 311 of the exhaust chambers 312a, 312b. The main portion 311 of the exhaust chambers 312a, 312b is an open space and helps to reduce back pressure, which can accumulate if the fin array 314 extends all the way to the baffle 304. In some embodiments, there is a gap of at least 5 mm between the end of the fin array 314 and the nearest portion of the baffle 304, such as about 5 mm to about 40 mm.

[0041] A baffle 304 extends from the outer surface 328 of each exhaust channel body 204a, 204b toward the inner surface 330 of each exhaust channel body 204a, 204b. The outer surface 328 is the inner surface of the exhaust chambers 312a, 312b furthest from the centerline C. The inner surface 330 is the inner surface of the exhaust chambers 312a, 312b closest to the centerline C. Therefore, the baffle 304 in the first exhaust channel body 204a extends from the outer surface 328 of the first exhaust chamber 312a toward the inner surface 330 of the first exhaust chamber 312a or the centerline C of the exhaust system 178. The baffle 304 in the second exhaust channel body 204b extends from the outer surface 328 of the second exhaust chamber 312b toward the inner surface 330 of the second exhaust chamber 312b or the centerline C of the exhaust system 178.

[0042] The baffle 304 extends at an angle φ relative to the outer surface 328 of each exhaust chamber 312a, 312b. The angle φ is an interior angle facing the fin array 314. The angle φ is an obtuse angle, such that the angle φ is greater than about 90 degrees, such as about 100 degrees to about 170 degrees, such as about 100 degrees to about 160 degrees, such as about 110 degrees to about 145 degrees. Setting the angle of the baffle 304 helps to control the restriction rate of the exhaust chambers 312a, 312b. The baffle 304 is set at an angle other than 0 degrees or 90 degrees relative to the orientation of the fins 302, such as an angle between about 10 degrees and about 80 degrees relative to the orientation of the fins 302. The baffle 304 extends across more than 50% of the width of each exhaust chamber 312a, 312b, such as more than 60% or more of the width of each exhaust chamber 312a, 312b, such as more than 70% of the width of each exhaust chamber 312a, 312b. In some embodiments, the radius of curvature of the baffle 304 is defined as the radius from the center of the process volume 136 of the deposition chamber 100 to the air guide surface 332. In some embodiments, the radius of curvature changes across the air guide surface 332, such that the portion of the air guide surface 332 closer to the inner surface 330 has a smaller radius of curvature. The radius of curvature of the air guide surface 332 may also be a radius other than the radius starting from the center of the process volume 136. Each baffle 304 has an air guide surface 332. The air guide surface 332 is the surface of the baffle 304 facing the main portion 311 of the exhaust chambers 312a, 312b and the fin array 314.

[0043] The baffle 304 may have a curved air guide surface 332, a straight air guide surface 332, or a multifaceted air guide surface 332. The air guide surface 332 is shown as curved in Figure 3A, but may be straight in some embodiments. In curved embodiments, the air guide surface 332 follows the circumference of a circle, ellipse, hyperbola, or parabola. Curved surfaces allow for better airflow control while reducing eddies or turbulence within the gas flow path. The curvature of the air guide surface 332 may vary depending on the size of the deposition chamber 100 and the size of the exhaust system 178. An air guide surface 332 with a large radius of curvature enables smooth guidance of airflow through the exhaust chambers 312a, 312b.

[0044] Exhaust outlet openings 308a and 308b are disposed between the innermost portion of each baffle 304 and the inner surface 330 of each exhaust chamber 312a and 312b. A first exhaust outlet opening 308a is disposed within a first exhaust chamber 312a and connects the first exhaust chamber 312a to the collector chamber 316. A second exhaust outlet opening 308b is disposed within a second exhaust chamber 312b and connects the second exhaust chamber 312b to the collector chamber 316.

[0045] One or more growth monitors 310 are located within or directly downstream of exhaust outlet openings 308a and 308b. A first growth monitor 310 is positioned within or directly downstream of the first exhaust outlet opening 308a. A second growth monitor 310 is positioned within or directly downstream of the second exhaust outlet opening 308b. Positioning the growth monitor 310 downstream of the exhaust outlet openings 308a and 308b is defined as positioning the growth monitor 310 within 10 mm of the exhaust outlet openings 308a and 308b and away from the fin array 314.

[0046] The baffle 304 narrows the passage of exhaust gas through the exhaust chambers 312a and 312b, thereby increasing the density or concentration of the exhaust gas flowing through the growth monitor 310. The growth monitor 310 is positioned in the top surface 326 or bottom surface 327 (Figure 3B) of the exhaust chambers 312a and 312b such that it does not obstruct the third flow path 322, but is instead aligned with the third flow path 322. The growth monitor 310 is at least partially located inside the collector chamber 316.

[0047] Before being removed from the exhaust collector 206 via the pipe opening 306 (Figure 3B) of the exhaust pipe 323, the exhaust gas passes through the growth monitor 310 and enters the collector chamber 316. The width of the collector chamber 316 adjacent to the exhaust outlet openings 308a and 308b is wider than the exhaust outlet openings 308a and 308b, such that the width of the collector chamber 316 adjacent to each exhaust outlet opening 308a and 308b is similar to the inlet width W1, and the total width of the collector chambers 316 is similar to or greater than twice the inlet width W1.

[0048] A pipe opening 306 is provided in a portion of the collector chamber 316 opposite to the exhaust outlet openings 308a, 308b. The pipe opening 306 is configured to enable the exhaust gas in the exhaust collector 206 to be discharged to the exhaust pump 157 via the exhaust pipe 323. Adjacent to the pipe opening 306 and within the collector chamber 316 is another growth monitor 310. The growth monitor 310 adjacent to the pipe opening 306 is provided on the rear sidewall 321 (Figure 3B) of the collector chamber 316 furthest from the exhaust outlet openings 308a, 308b. In some embodiments, the growth monitor 310 is provided directly above or within the pipe opening 306, such as in the upper part of the exhaust pipe 323.

[0049] At least the fins 302 and baffles 304 are formed of or coated with a material having high thermal conductivity, such as a thermal conductivity greater than about 100 W / m·°K, such as greater than about 150 W / m·°K, such as greater than about 175 W / m·°K. The material of the fins 302 is selected to reduce contamination of the deposition chamber 100 while maintaining the temperature of the exhaust gas flowing through the exhaust chambers 312a, 312b before flowing through the growth monitor 310. In some embodiments, at least a portion of the walls forming the exhaust chambers 312a, 312b is coated with a high thermal conductivity material similar to that of the fins 302 and baffles 304. The interior of the exhaust gas collector 206 may similarly be coated with a high thermal conductivity material. The high thermal conductivity material may be silicon carbide (SiC). Other suitable high thermal conductivity materials are considered. In some embodiments, the fins 302 and baffles 304 are formed of graphite and coated with silicon carbide. The high thermal conductivity material in the process chamber 136 conducts heat and reduces the cooling rate of the exhaust gas flowing through the exhaust chambers 312a and 312b. This ensures the exhaust gas is heated before flowing through the growth monitor 310, enabling more consistent film formation on the monitor, thus providing a more accurate estimate of the film growth rate within the process chamber.

[0050] Figure 3B shows a cross-sectional side view of the exhaust system 178 of the deposition chamber 100 of Figure 1 according to an embodiment of this disclosure. As shown in Figure 3B, exhaust chambers 312a, 312b of the exhaust system 178 extend through at least a portion of the flow module 112, such that exhaust chambers 312a, 312b extend through the flow module 112. Fins 302 are disposed adjacent to the process volume 136.

[0051] The fins 302 and baffles 304 extend the entire height of the exhaust chambers 312a and 312b, such that the fins 302 and baffles 304 extend between the top surface 326 and the bottom surface 329 of the exhaust chambers 312a and 312b. A growth monitor within the fin array 314 is disposed on the top surface 326.

[0052] The exhaust collector 206 is connected to the rear end of the exhaust system 178. The exhaust collector 206 includes a top surface 324, a bottom surface 327, and a rear sidewall 321. A growth monitor 310, located downstream of the exhaust outlet openings 308a and 308b, is situated on the top surface 324 of the collector chamber 316 within the exhaust collector 206. Another growth monitor 310 is disposed on the rear sidewall 321 of the collector chamber 316. The positioning of the growth monitors 310 enables accurate film growth rate measurement via each growth monitor 310. Measurement values ​​from each growth monitor 310 can be mapped to view differences in growth rate across different locations on the substrate 102.

[0053] A pipe opening 306 is disposed through the bottom surface 327 of the collector chamber 316 and leads to an exhaust pipe 323. The exhaust pipe 323 extends downward from the pipe opening 306 and is fluidly connected to the exhaust pump 157. Another growth monitor 310 may be located on the inner wall of the exhaust pipe 323 downstream of the growth monitor 310 on the rear side wall 321 of the collector chamber 316.

[0054] In some embodiments, more or fewer growth monitors 310 may be used within the exhaust system 178. In some embodiments, only the growth monitors 310 adjacent to the exhaust outlet openings 308a, 308b are disposed within the exhaust system 178. In other embodiments, the growth monitor 310 adjacent to the exhaust outlet openings 308a, 308b may be a single growth monitor 310. In still other embodiments, growth monitors 310 adjacent to the exhaust outlet openings 308a, 308b and growth monitors 310 on the rear sidewall 321 of the collector chamber 316 are used.

[0055] Figure 4 illustrates a growth monitor 310 for use in the deposition chamber 100 of Figure 1 according to an embodiment of this disclosure. The growth monitor 310 includes a sensor holder 402, a quartz crystal 406 disposed within the sensor holder 402, a rear contact 408 contacting a first side 422 of the quartz crystal 406, a front contact 410 contacting a second side 424 of the quartz crystal 406, a protective coating 416 disposed on the second side 424 of the quartz crystal 406, and a sensor opening 414 disposed through the sensor holder 402 and exposing the protective coating 416 to gas flowing through the exhaust system 178.

[0056] The growth monitor 310 is configured to be positioned within the deposition chamber 100, and therefore takes into account the reaction process chemicals within the exhaust system 178. The materials of the protective coating 416, sensor holder 402, rear contact 408, and front contact 410 affect the reactivity of the growth monitor 310 with the process chemicals within the deposition chamber 100. Therefore, the selected material composition reduces the reactivity of the growth monitor 310 with the process chemicals within the deposition chamber 100, while still enabling accurate film thickness measurements performed on the growth monitor 310.

[0057] The sensor holder 402 serves as a housing in which the rear contact 408, the front contact 410, and the quartz crystal 406 are disposed. The sensor holder 402 is formed in multiple parts, such as a first part 405 and a second part 404. The first part 405 has a cavity formed therein, in which the rear contact 408 is located. The quartz crystal 406 is also located in the cavity and contacts the rear contact 408.

[0058] The second portion 404 includes a sensor opening 414 disposed therein and is positioned above the side of the first portion 405, which includes a cavity. A front contact 410 is located between the first portion 405 and the second portion 404. The front contact 410 is held in place by the clamping force of the first portion 405 and the second portion 404. The front contact 410 is annular, such that it covers the exterior of the second side 424 of the quartz crystal 406 but does not cover the central portion of the second side 424. A protective coating 416 is disposed within the ring formed by the front contact 410 and contacts the second side 424 of the quartz crystal 406. The protective coating 416 is at least partially disposed within the sensor opening 414, such that the protective coating 416 is exposed to exhaust gas flowing through the exhaust system 178. The protective coating 416 and the quartz crystal 406 are at least partially held in place by the clamping force between the first portion 405 and the second portion 404. One or more sealing rings 412 are disposed within the second portion 404 and contact the exposed surface 426 of the protective coating 416. The one or more sealing rings 412 are configured to provide a seal between the atmosphere within the exhaust system 178 and other components of the growth monitor 310 that are not protected by the coating 416.

[0059] The protective coating 416 is formed of alumina (Al2O3) or silicon oxide such as silicon dioxide (SiO2). The protective coating 416 is formed of a material that will not degrade when exposed to epitaxial deposition process conditions or process gases. The protective coating 416 may be a lens or a coating applied to the quartz crystal 406. The protective coating 416 has a thickness of less than about 10 μm, such as about 1 nm to about 10 nm, such as about 1 nm to about 5 nm. The small thickness enables protection of the quartz crystal 406 without significantly damping the oscillation of the quartz crystal 406.

[0060] At least one of the rear contact 408 or the front contact 410 is formed of a gold-containing material, such as a gold alloy or pure gold. Both the rear contact 408 and the front contact 410 may be formed of a gold-containing material. The gold-containing material reduces the reaction between the rear contact 408 and the front contact 410 and the process chemicals within the deposition chamber 100. In some embodiments, the rear contact 408 and the front contact 410 are coated with a gold-containing material.

[0061] A first portion 405 is provided through the sensor holder 402 in the cooling mechanism 420. The cooling mechanism 420 may be a coolant passage provided through the main body of the first portion 405. The cooling mechanism 420 may be a coolant passage configured to receive cooling water.

[0062] One or more sealing rings 412 are formed of a polymer or plastic compatible with the epitaxial deposition process at a temperature of about 200°C. In some embodiments, one or more sealing rings 412 may be O-rings or another type of gasket.

[0063] Figure 5 illustrates a control schematic 500 for use within the deposition chamber 100 of Figure 1 according to an embodiment of this disclosure. The controller 120 is configured to receive data or inputs as sensor readings 502 from each growth monitor 310. The controller 120 is equipped with or communicates with a system model 506 of the deposition chamber 100. The system model 506 includes a heating model and an airflow module. The system model 506 is a program configured to estimate airflow and heating within the deposition chamber 100 throughout the deposition process. The controller 120 is further configured to store readings and perform calculations 504.

[0064] Readings and calculations 504 include previous sensor readings 502, such as any previous sensor readings within the deposition chamber 100. Readings and calculations 504 further include calculated values ​​stored after the sensor readings 502 are measured by the controller 120 and run via the system model 506. Therefore, the controller 120 is configured to retrieve the stored readings and calculations 504 and save them for future use. Maintaining previous readings and calculations enables the controller 120 to adjust the system model 506 over time to reflect a more accurate version of the deposition chamber 100.

[0065] In the embodiments described herein, controller 120 includes a programmable central processing unit (CPU), an input control unit, and a display unit (not shown) that operate in conjunction with memory and mass storage devices. Controller 120 monitors the flow rates of precursors, process gases, and purge gases. Support circuitry is coupled to the CPU to support the processor in a conventional manner. In some embodiments, controller 120 includes a plurality of controllers 120 such that stored readings and calculations 504 and system models 506 are stored in controllers separate from the controllers 120 that operate the deposition chamber 100. In other embodiments, all system models 506 and stored readings and calculations 504 are stored within controller 120.

[0066] The controller 120 is configured to control the heating and airflow through the deposition chamber 100 by providing an output to the lamp and airflow controller 508. The lamp and airflow controller 508 includes an upper lamp 141, a lower lamp 143, a process gas source 151, a purge gas source 162, and an exhaust pump 157. The controller 120 can also control the moving parts 121 within the deposition chamber 100.

[0067] Controller 120 is configured to adjust the output of each lamp and airflow controller 508 based on sensor readings 502, system model 506, and stored readings and calculations 504. Controller 120 includes embedded software and compensation algorithms to calibrate the frequency shift of growth monitor 310 to the film thickness on substrate 102. The film thickness on substrate 102 can be measured as substrate 102 leaves the deposition chamber or between process operations to provide a reference for the film thickness growth rate measured using growth monitor 310. Controller 120 may include machine learning algorithms and may use regression or clustering techniques. The algorithms may be unsupervised or supervised.

[0068] Figure 6 illustrates a method 600 for adjusting process conditions within the deposition chamber 100 of Figure 1 according to an embodiment of this disclosure. Method 600 utilizes a growth monitor 310 within the deposition chamber 100 and a controller 120 described herein to improve film thickness uniformity and characteristics across substrate 102.

[0069] During method 600, a first substrate is processed in a processing chamber during operation 602. The first substrate may be substrate 102 and the processing chamber is deposition chamber 100. Processing the first substrate during operation 602 includes performing a deposition process, such as an epitaxial deposition process, on the first substrate. The deposition process grows a film on the first substrate and includes heating the substrate using an upper lamp 141 and a lower lamp 143. A process gas inlet 114 and a purge gas inlet 164 flow through the process volume 136 and are subsequently discharged via an exhaust gas outlet 116.

[0070] While the first substrate is being processed in the processing chamber, the growth monitor 310 is used to measure film thickness growth on the monitor during another operation 604. The measurement of film thickness growth on the growth monitor 310 is performed as a rolling operation. A controller (such as controller 120) is configured to receive inputs from a combination of the growth monitor 310 described with respect to figures 3A-3B. The inputs are used to estimate film growth on the first substrate. Once the processing of the first substrate is complete in the processing chamber, during another operation 606, the film thickness can be measured using one or more other non-contact sensors in or adjacent chambers. The measurement of film growth on the first substrate during operation 606 is performed in a non-destructive manner, such as by using one or more non-contact sensors. The non-contact sensors may be laser thickness gauges and may be capable of multiple discrete measurements across the surface of the first substrate or capable of scanning the length of the first substrate.

[0071] The non-contact sensor used during operation 606 may not be used for film thickness measurement during substrate processing because process gases and radiation from the heating source can interfere with sensor readings, reducing reading sensitivity and accuracy. Therefore, the use of a non-contact sensor during operation 606 limits the ability to determine and manage heating and airflow changes within the process volume during substrate processing. The growth monitor 310 advantageously enables the adjustment of process conditions, such as heating and airflow, while processing the first substrate.

[0072] Measurement of film growth on the first substrate enables the calculation of the growth rate on the first substrate during another operation 608. Calculating the growth rate on the first substrate during operation 608 verifies the accuracy of the model used within the controller and enables the processing chamber model to be adjusted during another operation 610. Adjusting the processing chamber model during operation 610 enables better use of the growth monitor 310 for specific processes. Once the model is adjusted, processing of another substrate (such as a second substrate) is performed, and operations 602, 604, 606, 608, and 610 are repeated. Operations 602, 604, 606, 608, and 610 of method 600 can be cycled to continuously adjust the accuracy of the processing chamber model and improve film thickness growth results during operation 610. When preventative maintenance is performed on the processing chamber, the processing chamber model can be reset or adjusted, and method 600 restarts. Therefore, the film thickness between substrates is a continuously improving result. This further enables precise film thickness and overcomes the changes in processing chamber characteristics that occur as the film accumulates on the surface of the process volume and lamps age.

[0073] Although the foregoing content relates to embodiments of the present disclosure, other and further embodiments of the present disclosure may be designed without departing from its basic scope, and its scope is determined by the appended patent application scope. [Simplified Explanation of the Diagram]

[0008] In order to understand the above features of this disclosure in detail, a more specific description of the disclosure briefly summarized above can be obtained by referring to the embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings show only exemplary embodiments and should therefore not be regarded as limiting its scope, and other equivalent embodiments are permissible.

[0009] Figure 1 is a schematic diagram of a deposition chamber according to an embodiment of the present disclosure.

[0010] Figure 2 shows a cross-sectional plan view of the deposition chamber of Figure 1 according to an embodiment of the present disclosure.

[0011] Figure 3A shows a cross-sectional plan view of the exhaust system of the deposition chamber of Figure 1 according to an embodiment of the present disclosure.

[0012] Figure 3B shows a cross-sectional side view of the exhaust system of the deposition chamber of Figure 1 according to an embodiment of this disclosure.

[0013] Figure 4 shows a growth monitor for use in the deposition chamber of Figure 1 according to an embodiment of this disclosure.

[0014] Figure 5 shows a schematic diagram of control within the deposition chamber of Figure 1 according to an embodiment of this disclosure.

[0015] Figure 6 illustrates a method for adjusting process conditions in the deposition chamber of Figure 1 according to an embodiment of the present disclosure.

[0016] For ease of understanding, the same element symbols are used where possible to indicate the same elements common to the figures. It is contemplated that elements and features of one embodiment can be advantageously incorporated into other embodiments without further description. [Biomaterial Storage]

[0075] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. An exhaust channel body suitable for semiconductor substrate processing, comprising: a first exhaust chamber; a first exhaust inlet opening formed through a first end of the exhaust channel body and fluidly connected to the first exhaust chamber; a first plurality of fins disposed adjacent to the first exhaust inlet opening within the first exhaust chamber; a first exhaust outlet opening formed through a second end of the exhaust channel body and fluidly connected to the first exhaust chamber; a first baffle disposed adjacent to the first exhaust outlet opening and configured to narrow a first width of the first exhaust chamber; and at least one growth monitor disposed downstream of the first baffle and configured to measure a thickness of a material deposited on the at least one growth monitor.

2. The exhaust channel body as described in claim 1, wherein the at least one growth monitor is a quartz crystal film thickness monitor.

3. The exhaust passage body as claimed in claim 1, wherein the first baffle is oriented to narrow the first exhaust chamber as it extends toward the first exhaust outlet opening.

4. The exhaust passage body as claimed in claim 3, further comprising: a second exhaust chamber; a second exhaust inlet opening formed through the first end of the exhaust passage body and fluidly connected to the second exhaust chamber; a second plurality of fins disposed adjacent to the second exhaust inlet opening within the second exhaust chamber; a second exhaust outlet opening formed through the second end of the exhaust passage body and fluidly connected to the second exhaust chamber; and a second baffle disposed adjacent to the second exhaust outlet opening and configured to narrow a second width of the second exhaust chamber.

5. The exhaust passage body as claimed in claim 1, wherein the first exhaust inlet opening has an inlet width and the first exhaust outlet opening has an outlet width, the ratio of the inlet width to the outlet width being approximately 2:1 to approximately 20:

1.

6. The exhaust passage body as described in claim 5, wherein the inlet width of the first exhaust inlet opening is about 10 mm to about 210 mm.

7. The exhaust passage body as described in claim 1, wherein the first plurality of fins includes at least four fins.

8. The exhaust passage body as claimed in claim 7, wherein each of the first plurality of fins is oriented to be parallel to each other.

9. An exhaust system suitable for semiconductor substrate processing, comprising: an exhaust channel body including: an exhaust chamber; an exhaust inlet opening formed through a first end of the exhaust channel body and having an inlet width; a plurality of fins disposed adjacent to the exhaust inlet opening in the exhaust chamber; an exhaust outlet opening formed through a second end of the exhaust channel body and fluidly connected to the exhaust chamber; at least one baffle disposed adjacent to the exhaust outlet opening and configured to narrow a width of the exhaust chamber to an outlet width smaller than the inlet width; and at least one growth monitor disposed downstream of the at least one baffle and configured to measure a thickness of a material deposited on the at least one growth monitor; and an exhaust collector coupled to the exhaust channel body at the exhaust outlet opening.

10. The exhaust system as claimed in claim 9, wherein the at least one growth monitor is a quartz crystal film thickness monitor.

11. The exhaust system as claimed in claim 10, wherein the quartz crystal film thickness monitor comprises: a sensor holder; a quartz crystal disposed within the sensor holder; a rear contact contacting a first side of the quartz crystal; a front contact contacting a second side of the quartz crystal; a protective coating disposed on the second side of the quartz crystal; and a sensor opening disposed through the sensor holder and exposing the protective coating to gas flowing through the exhaust chamber.

12. The exhaust system as claimed in claim 11, wherein at least one of the rear contact and the front contact comprises a gold material.

13. The exhaust system as claimed in claim 11, wherein the protective coating is one or a combination of alumina or silicon dioxide.

14. The exhaust system as claimed in claim 9, wherein the plurality of fins are made of a material with a thermal conductivity higher than about 100 W / m·°K.

15. The exhaust system as described in claim 14, wherein the material contains silicon carbide.

16. The exhaust system as claimed in claim 9, wherein the at least one growth monitor is disposed within the exhaust collector adjacent to the exhaust outlet opening.

17. The exhaust system as claimed in claim 9, wherein the at least one baffle is a curved plate.

18. A process system suitable for processing semiconductor substrates, comprising: a chamber body forming a process volume; a substrate support disposed within the process volume of the chamber body; an upper window disposed above the substrate support; a lower window disposed below the substrate support, wherein each of the upper window and the lower window further defines the process volume; an injector disposed through one side of the chamber body and configured to introduce a process gas into the process volume; an exhaust system disposed through a second side of the chamber body opposite to the injector and comprising: an exhaust passage body; an exhaust chamber disposed through the exhaust passage body; an exhaust inlet opening formed through a first end of the exhaust passage body, the exhaust inlet opening being configured to fluidly connect the exhaust chamber and the process volume; a plurality of fins disposed within the exhaust chamber; and an exhaust outlet opening formed through a second end of the exhaust passage body and fluidly connected to the exhaust chamber. At least one baffle disposed downstream of the plurality of fins and configured to narrow the width of the exhaust chamber to an outlet width less than an inlet width; and at least one growth monitor disposed downstream of the at least one baffle and configured to measure the thickness of a material deposited on the at least one growth monitor.

19. The process system of claim 18, wherein the at least one growth monitor communicates with a controller configured to determine the growth rate and adjust at least one of process gas flow rate, heating energy level or exhaust flow rate on the at least one growth monitor.

20. The process system of claim 19, wherein the controller compares the growth rate measured on the at least one growth monitor, a chamber thermal model, a chamber flow model, and previous monitor measurements to determine how to adjust at least one of the process gas flow rates, the heating energy levels, or the exhaust flow rates.

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