In situ reflectance measurements for real-time process control.

Abstract

In one embodiment, a method for monitoring the thickness of a film on a substrate includes generating light from a light source, collimating the light from the light source to form a collimated beam, reflecting the collimated beam off a surface being measured to generate a reflected beam, splitting the reflected beam with a dichroic mirror, splitting the reflected beam into a first beam and a second beam, receiving the first beam from the dichroic mirror with a pyrometer, receiving the second beam from the dichroic mirror with a spectrometer, and analyzing data obtained from the pyrometer and the spectrometer to determine one or more properties of the surface being measured.

Description

[Technical Field]

[0001] TECHNICAL FIELD

[0001] Embodiments of the present disclosure generally relate to epitaxial chambers that include in-situ reflectance measurements for real-time process monitoring. [Background technology]

[0002]

[0002] Measurements of film thickness on processed substrates can be used in connection with processing steps. Typically, film thickness measurements are performed outside the processing chamber in which the substrate is processed after the processing step has occurred. Determining such measurements can be associated with inefficiencies and reduced throughput, as substrates that do not meet specifications can be unusable and multiple processing iterations may be required to obtain measurements that meet specifications.

[0003]

[0003] Furthermore, it is difficult to perform film thickness measurements within the processing chamber and during the processing step because processing equipment within the processing chamber can interfere with the measurement equipment, thereby hindering measurement accuracy. For example, heat emitted from heat lamps can interfere with measurement equipment. As another example, windows within the processing chamber can accumulate material during processing, hindering measurement accuracy.

[0004]

[0004] Therefore, there is a need for improved devices, systems, and methods that facilitate in-situ, real-time measurement processes. Summary of the Invention

[0005]

[0005] Embodiments of the present disclosure generally relate to apparatus, systems, and methods for real-time in-situ reflectometric monitoring of semiconductor processing, wherein the thickness of a film on a substrate is monitored during a substrate processing step that deposits a film on the substrate, the thickness being monitored while the substrate processing step is occurring.

[0006]

[0006] In one embodiment, a method for monitoring the thickness of a film on a substrate includes generating light from a light source, collimating the light from the light source to form a collimated light beam, directing the collimated light beam into a processing chamber of the substrate surface during an epitaxial process, reflecting the collimated beam from the substrate surface to generate a reflected beam, receiving the beam with a spectrometer to digitize the reflected signal on a high-level computing device such as a mass storage computer or server, and analyzing data obtained from the spectrometer to determine one or more characteristics of the substrate surface.

[0007] In another embodiment, a method for calibrating a substrate film thickness monitoring system is provided. The method includes generating a reference spectrum. Generating the reference spectrum includes rotating a susceptor, causing a light source to emit light, and reflecting the light from a reference surface disposed on the surface, where a spectrometer receives the light reflected from the reference surface, reflecting the light, and recording an initial data set associated with the light reflected from the reference surface. The calibrating method further includes determining a thickness of a film deposited on the substrate. Determining the thickness includes rotating the susceptor, causing a light source to emit light, and reflecting the light from the substrate, where a spectrometer receives the light reflected from the substrate, reflecting the light, recording a new data set associated with the light reflected from the substrate, and comparing the initial data set to the new data set to determine the film thickness.

[0008] In yet another embodiment, a method for calibrating a substrate film thickness monitoring system is provided. The method includes generating a reference spectrum and determining a thickness of a film deposited on a substrate. Generating the reference spectrum includes rotating a susceptor, causing a light source to emit light, reflecting the light from a reference surface where a spectrometer receives the light reflected from the substrate, reflecting the light, and recording an initial data set related to the light reflected from the substrate. Determining the thickness of a film deposited on the substrate includes rotating the susceptor, causing a light source to emit light, reflecting the light from the substrate where a spectrometer receives the light reflected from the reference surface, reflecting the light, and synchronizing the light reflected from the substrate with an angular position of the substrate during rotation, performing a deposition process where a new data set is created from the reflection of the light from the reference surface and the substrate, performing the deposition process, and comparing the initial data set to the new data set to determine the film thickness.

[0009]

[0009] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure briefly summarized above can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only exemplary embodiments, and therefore should not be considered limiting in scope, since the present disclosure may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of a system including an in-situ reflectance measurement system for processing a substrate, according to one embodiment. [Figure 2A]

[0011] 2 is a partial schematic cross-sectional view of an in situ reflectometry (ISR) system of the system shown in FIG. 1, according to one embodiment. [Figure 2B]

[0012] 2 is a partial schematic cross-sectional view of an in situ reflectometry (ISR) system of the system shown in FIG. 1, according to some embodiments. [Figure 3]

[0013] 2 is a partial cross-sectional view of the in-situ reflectance measurement system shown in FIG. 1 according to one embodiment. [Figure 4]

[0014] FIG. 1 is a cross-sectional view of a shortpass filter adapter plate according to one embodiment. [Figure 5]

[0015] FIG. 1 is a schematic block diagram of a method for calibrating a susceptor for in situ reflectance measurements, according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0016] For ease of understanding, wherever possible, like reference numerals have been used to designate like elements common to the figures. It is contemplated that components and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0012]

[0017] Embodiments of the present disclosure generally relate to an epitaxial chamber that integrates in situ reflected light measurements for real-time process monitoring in processing chambers such as epitaxial chambers. Specifically, unlike chemical vapor deposition (CVD), metrology is not typically used in epitaxial chambers due to challenges posed by directional crossflow across the substrate surface during epitaxial deposition. While CVD processes uniformly deposit material perpendicular to the substrate's major plane in alignment with metrology-based sensors, epitaxial deposition passes material perpendicular to the sensor, making real-time film thickness analysis challenging. During processing, light from the substrate is monitored as material is deposited on the substrate. The light is collected and analyzed by a spectrometer, computing device, and / or other optical measurement device to facilitate determination of substrate properties such as film thickness, film deposition rate, film optical properties, and / or Ge concentration within the film. Multiple measurements, such as film thickness, film deposition rate, and / or substrate temperature, can be made simultaneously using one or more measurement devices.

[0013]

[0018] FIG. 1 is a schematic cross-sectional view of a system 101 for processing a substrate, according to one embodiment. The system 101 includes a process chamber 100. The process chamber 100 is a deposition chamber and may be used as part of a cluster tool. The process chamber 100 is utilized to grow an epitaxial film on a substrate, such as a substrate 150. The substrate has a substrate surface on which material is grown or deposited during the epitaxial process. The process chamber 100 generates a crossflow of precursors (e.g., process gases) across the top surface of the substrate 150 during processing. The system 101 utilizes the process chamber 100 configured to perform an epitaxial deposition process on the substrate 150. Aspects and advantages of the present disclosure may be used for other substrate processing processes, such as chemical vapor deposition (CVD) chambers, atomic layer deposition (ALD) chambers, physical vapor deposition (PVD) chambers, etch chambers, ion implantation chambers, oxidation chambers, and / or other process chambers.

[0014]

[0019] The processing chamber 100 includes an upper housing module 102, a lower housing module 104, a chamber body assembly 106, a susceptor assembly 124, a lower window 120, and an upper window 122. The upper housing module 102 may be a lid or a part of the processing chamber lid 102. The susceptor assembly 124 is disposed between the susceptor assembly 124 and the lower housing module 104. The lower window 120 is disposed between the susceptor assembly 124 and the lower housing module 104. The upper window 122 is disposed between the susceptor assembly 124 and the upper housing module 102.

[0015]

[0020] The upper housing module 102 is disposed over the susceptor assembly 124 and is configured to heat a substrate, such as a substrate 150, disposed on the susceptor assembly 124. The upper housing module 102 includes an upper module body 126 and a plurality of lamp apertures 128 disposed through the upper module body 126. Each of the plurality of lamp apertures 128 includes an upper lamp 130 disposed therein. Each of the upper lamps 130 is coupled to a lamp base 129. Each of the lamp bases 129 supports one of the upper lamps 130 and electrically couples each of the upper lamps 130 to a power source (not shown). Each of the lamps 129 is fixed in a generally vertical orientation within the aperture 128. As described herein, the generally vertical orientation of the upper lamps 130 is approximately perpendicular to the substrate support surface of the susceptor assembly 124. However, other orientations are contemplated. The vertical orientation of the upper lamps 130 does not necessarily have to be perpendicular to the substrate support surface, but can be at an angle of about 30° to about 150° relative to the substrate support surface 153 of the susceptor assembly 124. The angle can be about 45° to about 135° relative to the substrate support surface 153 (e.g., about 70° to about 110° relative to the substrate support surface 153).

[0016]

[0021] The upper housing module 102 includes a pyrometer passage 131 (e.g., a light pipe). The pyrometer passage 131 may be centrally located within the upper housing module 102. The upper housing module 102 may also include at least a preheat ring (PHR) 161, a PHR sensor 221, and a PHR sensor passage 219 (shown in FIGS. 2A and 2B) for measuring the thickness of a film on a preselected coupon 151 (e.g., formed of SiC) on the PHR 161, which can provide reference information for the process on the substrate 150. A similar sensor can be implemented in combination with a pyrometer for dome applications or without a pyrometer (not shown) to measure parameters at the substrate edge. Because the PHR 161 is static, the PHR sensor 221 allows the reflected signal from the PHR coupon 151 to be used without interference from rotation or wobble. The correlation established between the thickness of the substrate and a known PHR coupon 151 can be used for manufacturing process control on multiple substrates, including unknown patterned substrates, by providing a reference of known values.

[0017]

[0022] The pyrometer passage 131 extends through the upper module body 126 from a first (e.g., lower) surface of the upper module body 114 to a second (e.g., upper) surface of the upper module body 126. The pyrometer passage 131 is configured to allow light to pass between the surface of the substrate 150 and an in-situ reflected light measurement (ISR) system 185. The PHR sensor passage 219 (shown in FIGS. 2A and 2B) extends through the upper module body 126 from a first surface of the upper module body 114 to a second surface of the upper module body 126. The PHR sensor passage 219 is configured to allow light 229 to travel between the surface of the coupon 151 or the surface of the substrate 150 and the ISR system 185. The reflected signal from the PHR coupon 151 can be directed and collected at a right angle or another adaptable angle based on the suitability of the hardware integration. The ISR system 185 includes a housing 103 that houses one or more optical elements therein to facilitate processing of the optical signal.

[0018]

[0023] An upper plenum 180 is defined between the bottom surface of the upper module body 126 and the upper window 122. Heated gas is supplied to the upper plenum 180. A heated gas exhaust passage 142 is also disposed through the upper module body 126. The heated gas exhaust passage 142 is coupled to a heated exhaust pump 140. The heated exhaust pump 140 removes gas from the upper plenum 180.

[0019]

[0024] The lower housing module 104 is disposed below the susceptor assembly 124 and is configured to heat the bottom surface of a substrate 150 disposed on the susceptor assembly 124. The lower housing module 104 includes a lower module body 182 and a plurality of lamp apertures 186 disposed through the lower module body 182. Each of the plurality of lamp apertures 186 includes a lower lamp 188 disposed therein. Each of the lower lamps 188 is disposed in a generally vertical orientation and coupled to a lamp base 184. Each of the lamp bases 184 supports one of the lower lamps 188 and electrically couples each of the lower lamps 188 to a power source. As described herein, the generally vertical orientation of the lower lamps 188 is described with respect to the substrate support surface 153 of the susceptor assembly 124. It is contemplated that the lamp orientation may be other than generally vertical, such as at an angle of about 30° to about 150° with respect to the substrate support surface 153. The angle can be between about 45° and about 135° relative to the substrate support surface 153 (eg, between about 70° and about 110° relative to the substrate support surface 153).

[0020]

[0025] During a substrate processing process, the upper lamps 130 are powered to generate radiant energy (e.g., heat) and direct the radiant energy toward the substrate 150 and susceptor 157. During a substrate processing process, the lower lamps 188 are powered to generate radiant energy upward toward the substrate 150 and susceptor 157.

[0021]

[0026] The lower lamp module 104 includes a susceptor shaft passage 195 and a pyrometer passage 192. The support shaft 155 of the susceptor assembly 124 is disposed through the susceptor shaft passage 195. The susceptor shaft passage 195 is centrally disposed through the lower module body 182. The susceptor shaft passage 195 allows the support shaft 155 of the susceptor assembly 124 and a portion of the lower window 120 to pass through the lower module body 182.

[0022]

[0027] A pyrometer passage 192 is disposed through the lower module body 182 outside of the susceptor shaft passage 195 so that a lower pyrometer 190, such as a scanning pyrometer, can measure the temperature of the bottom surface of the substrate 150 or the bottom surface of the susceptor 157 of the susceptor assembly 124. The lower pyrometer 190 is disposed below the lower module body 182 adjacent to the pyrometer passage 192. The pyrometer passage 192 extends from the bottom surface of the lower module body 182 to the top surface of the lower module body 182.

[0023]

[0028] The upper chamber space 111 is the portion of the processing space 110 where the substrate 150 is processed and where one or more process gases are injected. The lower chamber space 113 is the portion of the processing space 110 where the substrate 150 is loaded onto (or removed from) the susceptor assembly 124. The upper chamber space 111 may also be understood as the space above the susceptor 157 while the susceptor assembly 124 is in the processing position. The susceptor assembly 124 is shown in a lower position (e.g., a substrate 150 loading position) in FIG. 1 . The lower chamber space 113 is understood to be the space below the susceptor 157 of the susceptor assembly 124 while the susceptor assembly 124 is in the processing position. The processing position is a position where the substrate 150 is positioned at or above the horizontal plane 125.

[0024]

[0029] The upper cooling ring 118 and the lower cooling ring 112 are disposed on opposite sides of the chamber body assembly 106. The upper cooling ring 118 is disposed above the injection ring 116 and is configured to cool the injection ring 116. The lower cooling ring 112 is disposed below the injection ring 116. The upper cooling ring 118 includes coolant passages 146 disposed therethrough. The coolant circulating through the coolant passages 146 may include water, oil, or other fluids. The lower cooling ring 112 also includes coolant passages 148 disposed therethrough. The coolant circulating through the coolant passages 148 is similar to the coolant circulating through the coolant passages 146 of the upper cooling ring 118. The upper cooling ring 118 and the lower cooling ring 112 can help secure the injection ring 116 in place. The upper cooling ring 118 can partially support the upper lamp module 102, while the lower cooling ring 112 can partially support the lower lamp module 104.

[0025]

[0030] The use of upper cooling ring 118 and lower cooling ring 112 reduces the temperature of injection ring 116 without requiring additional cooling channels disposed therethrough. The use of upper cooling ring 118 and lower cooling ring 112 reduces the manufacturing costs of injection ring 116, which may be replaced more frequently than upper cooling ring 118 and lower cooling ring 112. The present disclosure contemplates that injection ring 116 may include one or more additional cooling passages formed therein.

[0026]

[0031] One or more gas injectors 108 are positioned through one or more openings in the injection ring 116 to supply a gas, such as a process gas, to the processing space 110. The present disclosure contemplates that multiple gas injectors can be positioned through the injection ring 116. The gas injectors can be positioned at an angle greater than about 5° from the XY plane of the substrate 150 (e.g., an angle greater than about 10° from the XY plane). Each of the injectors is fluidly coupled to one or more process gas sources, such as a first process gas source and / or a second process gas source. In some embodiments, only the first process gas source is utilized. In some embodiments in which both the first and second process gas sources are utilized, there can be two gas outlets in each gas injector. According to some embodiments, which can be combined with other embodiments, the first process gas source is a process gas and the second process gas source is a cleaning gas. The cleaning gas may be used to clean features of the ISR system 185 in the processing space 110 and / or features of the reflectometer system in the processing space 110 .

[0027]

[0032] The upper window 122 is disposed between the injection ring 116 and the upper housing module 102. The upper window 122 is an optically transparent window through which radiant energy generated by the upper lamp module 102 can pass. The upper window 122 is formed of quartz or a glass material. The upper window 122 is dome-shaped and is referred to as an upper dome, although a flat window is also contemplated. The outer edge of the upper window 122 forms one or more peripheral supports 172. The peripheral supports 172 are thicker than the central portion of the upper window 122. The peripheral supports 172 are disposed above the injection ring 116. The peripheral supports 172 are connected to the central portion of the upper window 122. The peripheral supports 172 are optically opaque and can be formed of opaque quartz.

[0028]

[0033] The lower window 120 is disposed between the susceptor assembly 124 and the lower housing module 104. The lower window 120 is an optically transparent window through which radiant energy generated by the lower lamp module 104 can pass. The lower window 120 is formed of quartz or a glass material. The lower window 120 is dome-shaped and may be referred to as a lower dome, although a flat lower window 120 is also contemplated. The outer edge of the lower window 120 forms a peripheral support 170. The peripheral support 170 is thicker than a central portion of the lower window 120. The peripheral support 170 is connected to the central portion of the lower window 120.

[0029]

[0034] Various liners and heaters are disposed within the chamber body assembly 106 and the processing space 110. As shown in FIG. 1 , an upper liner 156 and a lower liner 154 are disposed within the chamber body assembly 106. The upper liner 156 is disposed above the lower liner 154 and inside the inject ring 116. The upper liner 156 and the lower liner 154 are configured to be bonded together and / or the upper liner 156 is supported on the lower liner 154. The upper liner 156 and the lower liner 154 are configured to shield the inner surface of the inject ring 116 from process gases within the processing space 110. The upper liner 156 and the lower liner 154 also serve to reduce heat loss from the processing space 110 to the inject ring 116. Reducing heat loss improves heating uniformity of the substrate 150, enabling more uniform deposition on the substrate 150 during a processing step (e.g., an epitaxial deposition step). A preheat ring (PHR) 161 is supported on a ledge 160 of the lower liner 154. The PHR 161 and the edge of the substrate are located within the outer radial region of the processing space 110.

[0030]

[0035] An upper heater 158 and a lower heater 152 are also disposed within the chamber body assembly 106 and the processing space 110. As shown in FIG. 1 , the upper heater 158 is disposed between the upper liner 156 and the inject ring 116, while the lower heater 152 is disposed between the lower liner 154. Both the upper heater 158 and the lower heater 152 are disposed inside the chamber body assembly 106, allowing for more uniform heating of the substrate 150 while it is in the processing chamber 100. The upper heater 158 and the lower heater 152 reduce heat loss to the walls of the chamber body assembly 106 and create a more uniform temperature distribution around the processing space 110. Both the upper heater 158 and the lower heater 152 may be configured to have a heated fluid passed therethrough or may be resistive heaters. The upper heater 158 and the lower heater 152 are further shaped to accommodate an opening, such as a substrate entry port, through the inject ring 116.

[0031]

[0036] The susceptor assembly 124 is disposed within the process space 110 and configured to support the substrate 150 during processing. A controller 196 is configured to rotate the susceptor assembly 124 and the substrate 150 during substrate processing. The susceptor assembly 124 includes a planar substrate support surface 153 for supporting the substrate 150 and a shaft 155 extending through the lower window 120 and a portion of the lower lamp module 104. The susceptor assembly 124 is coupled to a movement assembly 194. The movement assembly 194 includes, for example, one or more motors or actuators. The movement assembly 194 is coupled to the controller 196 to induce rotation (stepped or continuous) about at least a central axis, axis A, vertical movement of the susceptor assembly 124, angular tilt of the susceptor assembly 124, or other movement. The controller 196 can report characteristics of the susceptor assembly 124 to a spectrometer and can instruct at least the light source 244 to flash. According to some embodiments, the rotating assembly controller 196 can receive and store data.

[0032]

[0037] 2A is a partial schematic cross-sectional view of the ISR system 185 of the system 101 shown in FIG. 1 , according to some embodiments. The ISR system 185 further includes a light source 244, a collimator 215, a sensor 245, a pyrometer 207, one or more preheat sensors 221 (two are shown), and a dichroic mirror 205 coupled to or disposed above the upper housing module 102. The ISR system 185 facilitates measurement of one or more properties of the substrate 150 (and / or the thin film disposed thereon). Exemplary properties include temperature, thin film growth rate, thin film thickness, optical properties of the thin film, and / or Ge concentration within the thin film.

[0033]

[0038] The light source 244 is configured to generate light 241. For example, the light source 244 may be a flash lamp capable of producing full-spectrum or partial-spectrum light. In one example, the spectrum of the generated light has wavelengths between about 200 nm and about 4 micrometers (e.g., 200 nm to about 800 nm and / or 3 micrometers to 4 micrometers). While full-spectrum light allows for a wide range of optical signals for analysis, in other embodiments, the light source may be limited to a specific wavelength of light or a specific wavelength range of light to achieve analysis. The light source 244 may be controlled by the controller 196. The light source 244 is in optical communication with the collimator 215 and directs the light 241 to the collimator 215 as directed by the controller 196. Optical communication may include a fiber optic cable connection, although other optical transmission methods are contemplated. The path of travel of the light from the light source 244 may be referred to as a propagation path. The collimated light 243 exits the collimator 215 and travels through the pyrometer passageway 131. The pyrometer passage 131 can be made of any material (e.g., sapphire) that can transmit light of a predetermined wavelength. The pyrometer passage 131 directs collimated light 243 onto the surface of the substrate 150 (or a thin film thereon) to facilitate measurement of one or more properties of the substrate 150 (or a thin film thereon). It is contemplated that in addition to or as an alternative to measuring the substrate 150, the susceptor surface, the coupon surface on the PHR 161 (or other surfaces) could be measured. For example, the surface of the substrate, susceptor surface, or coupon could be measured to establish an initial data set of wobble calibration metrics. As used herein, thin film and substrate or coupon may be used interchangeably unless the description specifically excludes one or the other.

[0034]

[0039] The collimated light 243 reflects off a target measurement surface, such as the substrate 150, and returns as reflected light 227. The reflected light 227 travels back through the pyrometer passage 131. The reflected light 227 exits the pyrometer passage 131 and travels to a dichroic mirror 205 aligned with the pyrometer passage 131 along the path of travel of the reflected light 227. According to some embodiments, the dichroic mirror 205 is a transparent material with a dielectric coating. The dielectric coating may include, but is not limited to, magnesium fluoride, tantalum pentoxide, and titanium dioxide. The dichroic mirror 205 reflects certain wavelengths of light while allowing other specifically selected wavelengths to pass. The wavelength range directed to the sensor 245 may be between about 100 nm and about 1000 nm, for example, within the range of 200 nm to 800 nm, for example, within the range of 200 nm to 400 nm, or for example, within the range of 400 nm to 800 nm. The dichroic mirror 205 directs light in a first desired range to one sensor and transmits the remaining wavelengths of light to at least another sensor, thereby enabling the use of multiple light-based sensors. In this manner, the ISR system 185 provides a compact measurement system, allowing for more sensors to be mounted in a smaller footprint. The dichroic mirror 205 is positioned or oriented in a plane generally perpendicular to the longitudinal axis of the pyrometer passage 131 at an angle of incidence A1 between about 30° and about 60°, for example, in the range of 35° to 55°. However, other angles of incidence are contemplated.

[0035]

[0040] 2A, light reflected from the dichroic mirror 205 is transmitted along optical path 211 to the pyrometer 207. According to some embodiments, only wavelengths of light between about 1.0 μm and about 6.0 μm, for example, between about 3.0 μm and about 4.0 μm, travel along optical path 211 to the pyrometer 207. As described above, the characteristics of the dichroic mirror 205 are selected to transmit or reflect light within a specific wavelength range. Light 247 that is transmitted through the dichroic mirror 205 is collimated by a collimator 215. The collimated light 213 is directed to a sensor 245. For example, the sensor 245 can be an optical spectrometer configured to measure wavelength-resolved intensity. The sensor 245 can further include a grating, an optical lens, a filter 421, and / or a linear array photodiode detector. The filter 421 can be a short-pass filter to limit noise from the lamp 128, or a dielectric filter. Dielectric filters include any thin-film-based filter capable of preventing certain wavelengths of light from passing through. While filter 421 is described as part of sensor 245, it is contemplated that the filter may be located elsewhere. For example, filter 421 may be part of dichroic mirror 205. Filter 421 is configured to allow only certain wavelengths of light to pass through. In one example, filter 421 passes only light with wavelengths less than 550 nm to reduce optical signal noise from lamps in a processing chamber and improve measurement accuracy. It is contemplated that filter 421 may be located in any optical path, including light reflected from substrate 150 (e.g., reflected light 227 to sensor 245) (e.g., reflected light 247 from dichroic mirror 205) (e.g., collimated light 243). In one example, filter 421 is an integral component of sensor 245, while in other examples, filter 421 is a component separate from sensor 245. According to some embodiments, the filter 421 is not included in the path, reducing the cost, complexity, and footprint of the ISR system 185.It should be noted that although the embodiments described herein may include filter 421 and / or dichroic mirror 205, both filter 421 and mirror 205 are optional and may be excluded from any embodiment or implementation described herein, as advantages may be achieved in their absence.

[0036]

[0041] The pyrometer 207, one or more PHR sensors 221, and sensor 245 may be connected to a controller 196 to facilitate their control and / or operation. The controller 196 may store information, data, algorithms, or other control parameters for performing the operations described herein. The controller 196 includes a central processing unit (CPU), memory containing instructions, and support circuitry for the CPU. The controller 196 controls various items directly or via other computers and / or controllers. In one or more embodiments, the controller 196 is communicatively coupled to a dedicated controller, with the controller 196 functioning as the central controller.

[0037]

[0042] The controller 196 includes a computer processor (e.g., a CPU) used to control various substrate processing chambers and equipment, as well as sub-processors thereon or therein. The memory, or non-transitory computer-readable medium, is one or more of random access memory (RAM), dynamic random access memory (DRAM), static RAM (SRAM), and synchronous dynamic RAM (SDRAM (e.g., DDR1, DDR2, DDR3, DDR3L, LPDDR3, DDR4, LPDDR4, etc.)), read-only memory (ROM), floppy disk, hard disk, flash drive, or any other form of digital storage (local or remote). Support circuits of the controller 196 are coupled to the CPU to support it. The support circuits include cache, power supplies, clock circuits, input / output circuits, subsystems, etc. Operating parameters and instructions are stored in the memory as software routines that are executed or invoked to transform the controller 196 into a special-purpose controller and control the operation of the system 101 described herein. The controller 196 is configured to perform any of the operations described herein. The instructions stored in the memory, when executed, cause one or more of the steps described herein to be performed.

[0038]

[0043] The ISR system 185 may optionally include one or more PHR sensors 221 positioned to receive data indicative of characteristics of the preheat ring of the system 101. Each PHR sensor 221 is configured to be aligned (e.g., vertically and / or optically aligned) with a PHR sensor passage 219. The PHR sensors 221 are spectrometers or channels of a multi-channel spectrometer configured to measure characteristics of a preheat ring (PHR), such as the PHR 161 (shown in FIG. 1). In one example, each PHR sensor 221 is configured to read a reference material in or on the PHR 161 for use as a film thickness reference. For example, the reference material may be a crystalline coupon with known characteristics. Each PHR sensor passage 219 extends between the bottom and top surfaces of the upper module body 126. In such an example, the PHR sensor passage is vertically aligned (and / or oriented toward) the PHR 161 (shown in FIG. 1). The PHR sensor passages 219 may be sealed at their top and bottom ends with a material (such as quartz or sapphire) that is transparent to light 229. In another embodiment, each PHR sensor passage 219 includes a fiber optic cable disposed thereon. It is contemplated that sensors similar to the PHR sensor 221, alone or in combination with a pyrometer, may be employed in the system 101 to analyze the substrate edge and measure the thickness and other properties of the thin film at the substrate edge, and the temperature of the surface.

[0039]

[0044] Additionally, the preheat ring sensor 221 allows for an estimation of the film thickness at the outer periphery of the substrate 150 due to its proximity to the preheat ring 161. Therefore, as deposition occurs on the preheat ring 161 during processing, the preheat ring sensor 221 can determine the film thickness at the preheat ring sensor. This thickness is an estimate of the deposited film thickness at the edge of the substrate 150. Therefore, measurements through the pyrometer passage 131 can be used to determine the film thickness at the center of the substrate 150, while measurements from the ring sensor 221 can be used to determine the film thickness at the edge of the substrate 150. Thus, the center-to-edge uniformity of the deposited film can be determined in situ and corrected, if necessary. It is contemplated that the center-to-edge uniformity can be corrected by modifying one or more process parameters during the deposition process. Additionally, sensors similar to the PHR sensor 221 can be employed in the system 101 to directly measure the edge film thickness of the substrate 150 by determining the substrate edge position.

[0040]

[0045] During processing, light from a light source 244 is used to determine the film thickness and / or film thickness deposition rate. The light is directed from the light source 244 to a collimator 215, e.g., by a fiber optic cable. The collimator 215 directs the light to a surface to be measured (e.g., the substrate 150). The light is reflected from the surface as a reflected light. The reflected light from the measurement surface of the substrate 150 facilitates measurement of the film thickness (film thickness growth rate and / or concentration of a component in the film, such as Ge). The reflected signal returns to the dichroic mirror and is split into multiple paths (e.g., propagation sub-paths). A first propagation sub-path directs the reflected light to the pyrometer 207, while a second propagation sub-path directs the reflected light to the collimator 215 and then to the sensor 245. The light intensity collected by the sensor 245 is analyzed for true reflectance and compared to a film model (e.g., Fresnel equation) using a nonlinear fitting equation or other empirically derived equation to determine the film thickness.

[0041]

[0046] In one example, the film thickness model is empirically derived by obtaining absorption / reflectance data for a predetermined wavelength of light for various films at multiple film thicknesses. The data may be collected at process conditions approximating a predetermined process recipe for processing future substrates, such as the process recipe for which the model is utilized. The data is then fitted to an equation, such as a nonlinear equation. Light received by the sensor 245 is analyzed for intensity (e.g., the true reflectance of light reflected from the measured specimen) and fitted to the empirically derived equation to determine the film thickness. In other words, the amount of light reflected from the substrate 150 surface varies as a function of the film thickness on the substrate 150 surface. The data and / or equation may also consider other optical properties, such as the refractive index and extinction coefficient of the film, to improve measurement accuracy. In one example, the film thickness model is derived from the apparatus and / or method used in U.S. Pat. No. 10,281,261, incorporated herein by reference.

[0042]

[0047] FIG. 2B is a partial schematic cross-sectional view of the system shown in FIG. 1 , according to some embodiments. FIG. 2B is similar to FIG. 2A , except that pyrometer 207 receives light 211 that has passed through dichroic mirror 205, and collimator 215 receives light 247 that is reflected from dichroic mirror 205. Collimator 215 can then collimate light 247 from dichroic mirror 205. Sensor 245 can then receive collimated light 213. According to some embodiments, which can be combined with other embodiments, collimator 215 can receive and collimate reflected light 227 from the substrate before dichroic mirror 205. In such embodiments, dichroic mirror 205 receives the collimated light. As shown in FIG. 2B , pyrometer 207 is located above mirror housing 103, so that reflected light 227 has a shorter path to pyrometer 207.

[0043]

[0048] The measured light intensity of the collimated light 213 is used to determine the thickness and / or growth rate of the film deposited on the surface of the substrate 150. For example, a lower light intensity may indicate a thicker film (due to more light being absorbed), and a higher light intensity may indicate a thinner film (due to more light being reflected).

[0044]

[0049] The thickness of the deposited film on the surface of the substrate 150 affects the light intensity of the collimated light 213 received by the sensor 245, and changes in light intensity can signal changes in the thickness of the deposited film on the surface of the substrate 150. In one or more examples, the measured spectrum of the returned collimated light 213 can be filtered to provide a value indicative of the measured light intensity only within a selected wavelength range. This wavelength range is beneficial because emissions from lamps (such as the upper lamp 130) are filtered out, improving the accuracy of measurements at the sensor 245. An optical filter 421 can be used to block a portion of the reflected light 227, including light at wavelengths outside the selected wavelength range. This can be done, for example, when light from the upper lamp 130 (or other lamps) is directed into the pyrometer passage 131, such as by reflecting off one or more internal chamber surfaces. Because inadvertent light can affect measurements at the sensor 245, filtering out unintended wavelengths improves measurement accuracy. In one or more examples, the selected wavelength range may exclude infrared light to reduce the effects of background infrared lamp radiation. In one non-limiting example, the wavelength range generated by the light source 244 is light with wavelengths within a range of about 200 nm to about 780 nm (e.g., about 200 nm to about 500 nm, or about 200 nm to about 400 nm, or about 500 nm to about 700 nm). The upper lamp 130 (or other lamps in the chamber) may be an infrared lamp. In such an example, the filter 421 filters (restricts the passage of) light in the infrared wavelength range (IR-A, IR-B, and / or IR-C), for example, light having wavelengths from 780 nm to 1.3 micrometers. Thus, the sensor 245 receives only the light generated by the light source 244, improving the accuracy of measuring the light reflected from the surface of the substrate 150. In another example, filter 421 filters light above 500 nm (e.g., above 550 nm) because signal degradation at high temperatures (e.g., above 200° C., e.g., above 600° C.) begins to occur in this range and above that wavelength. Embodiments disclosed herein reduce interference from infrared lamp radiation and increase the signal-to-noise ratio of optical sensor 245, enabling more accurate film growth measurements.

[0045]

[0050] The sensor 245 is used to monitor the film growth rate in situ within the processing chamber 100 and in real time during substrate processing. In situ monitoring increases throughput compared to conventional approaches because the substrate does not need to be removed from the processing chamber to perform thickness measurements. In one embodiment, which can be combined with other embodiments, the light intensity of the returning collimated light 213 is monitored continuously throughout substrate processing or at predetermined intervals throughout substrate processing. Once the desired film thickness is achieved, the deposition process is stopped. The substrate 150 may then be removed from the processing chamber 100, or further processing may occur in the processing chamber 100 according to a process recipe.

[0046]

[0051] FIG. 3 is a partial cross-sectional view of the ISR system 185 shown in FIG. 1 , according to one embodiment. The mirror housing 103 includes a top plate 395 coupled to a sidewall 396. The top plate 395 includes an aperture 397 adjacent to the collimator 215, and the sidewall 396 includes an aperture 398 adjacent to the pyrometer 207. The pyrometer 207 and the collimator 215 are coupled to the mirror housing 103. The mirror housing 103 is made of a metal alloy, such as an aluminum-containing alloy or steel, and houses the dichroic mirror 205 therein. The mirror housing 103 is coupled to a cooling plate 375. The cooling plate 375 is designed to maintain the mirror housing 103 at a predetermined temperature to extend the life of the mirror housing 103 and the components therein. Additionally or alternatively, the cooling plate 375 maintains the dichroic mirror 205 within a temperature range of predetermined optical properties when the dichroic mirror 205 has different optical properties at different temperatures. The cooling plate 375 includes one or more coolant channels 399 formed therein that are coupled to a cooling system. The cooling plate 375 is also made of a metal alloy, such as an aluminum-containing alloy or steel. The cooling plate 375 includes an aperture 363 formed therein adjacent to the pyrometer passage 131. The cooling plate 375 is located between the mirror housing 103 and the upper housing module 102 and reduces heat transfer from the upper housing module 102 to the mirror housing 103. The mirror housing 103 may include a mirror plate adapter 379 therein for supporting the dichroic mirror 205. The plate adapter 379 holds the dichroic mirror 205 at a predetermined orientation and position, such as at an angle of incidence A1 (shown in FIG. 2A ). In one example, the mirror plate adapter 379 is coupled to the mirror housing 103, although other support configurations are also contemplated. The mirror plate adapter 379 facilitates proper positioning of the dichroic mirror 205 without interfering with the light propagation path. Additionally, the mirror plate adapter 379 facilitates easy removal of the dichroic mirror 205 for replacement or cleaning.

[0047]

[0052] FIG. 4 is a cross-sectional view of a mirror adapter plate 379 according to one embodiment. The mirror adapter plate 379 is formed from a metal, ceramic, or polymeric material and includes a recess 403 formed therein adjacent to an aperture 401. The dichroic mirror 205 is positioned within the recess 403 and secured therein by adhesive, a mechanical fit, or a mechanical fastener such as a tab. The recess 403 can be tilted at an angle A2 from a first surface 405 of the mirror adapter plate 379. The angle A2 can be used to fine-tune the dichroic mirror 205. The angle A2 can be between about 0° and about 10° relative to the first surface 405 (e.g., between about 0.1° and about 5° relative to the first surface 405).

[0048]

[0053] It is also contemplated that an adapter plate similar to adapter plate 379 may be used to support filter 421 in the propagation path of light generated by light source 244. In such an example, the filter may be a circular optical element configured to filter out selected wavelengths of light. Similarly, an adapter plate for the filter may improve positioning of filter 421 and facilitate removal of filter 421 for replacement or cleaning.

[0049]

[0054] FIG. 5 is a schematic block diagram of a method 500 for calibrating the rotation of a susceptor assembly 124. The susceptor assembly 124 includes a susceptor 157. While the method 500 is described with reference to FIGS. 1 and 2A for ease of explanation, it is contemplated that the method 500 may be used in systems other than the system 101 of FIG. 1. It is further contemplated that the controller 196 may direct or otherwise control one or more aspects of the method 500. The method 500 takes into account wobble of the susceptor 157 while using in situ reflected light measurements. For example, during processing, the susceptor assembly 124 (shown in FIG. 1), and thus the substrate 150 thereon, rotates to promote uniform deposition. However, due to mechanical tolerances and other factors, the susceptor assembly 124 wobbles about the longitudinal (e.g., central) axis of the support shaft 155. Wobble of the support shaft 155 induces in-plane wobble of the susceptor 157 and the substrate 150 thereon during rotation. The in-plane wobble unintentionally changes the propagation path distance between sensors in the system (e.g., sensor 245, pyrometer 207, preheat ring sensor 221) and the sample being measured (e.g., substrate 150 and the preheat ring 161 and / or coupon thereon). The change in propagation path distance can affect measurement accuracy, and ultimately, film thickness measurement accuracy. However, method 500 mitigates the degradation of measurement accuracy due to wobble of the susceptor assembly 124.

[0050]

[0055] The method 500 utilizes a reference substrate to determine and account for wobble. The method 500 begins with step 502, which involves rotating the susceptor assembly 124 and the reference substrate thereon. The reference substrate is a substrate with known physical properties, such as surface reflectivity and optical properties such as refractive index and extinction coefficient. The controller 196 rotates the susceptor assembly 124 continuously or in steps.

[0051]

[0056] In step 504, light source 244 directs light along a propagation path toward the surface of the reference substrate. The light from light source 244 is provided at a known intensity and wavelength (or range of wavelengths), such as a range of wavelengths measured by sensor 245. The light from light source 244 is provided at a predetermined angular position of susceptor assembly 124. Step 504 also includes recording the angular position of susceptor assembly 124 at the time light is provided from light source 244. Thus, a correlation between the angular position of susceptor assembly 124 and light for reference substrate measurement can be later derived, as described below. It is contemplated that the light from light source 244 may be triggered by command of a controller or in response to a physical trigger (e.g., a contact switch).

[0052]

[0057] The angular position of the susceptor assembly 124 can be determined, for example, by rotating the susceptor assembly 124 using an actuator of known angular position (e.g., using a step encoder). Additionally or alternatively, the angular position of the susceptor assembly 124 can be determined using optical signals. In such an example, the shaft 155 of the susceptor assembly 124 may include a reflector. As the shaft 155 rotates, a sensor transmits and receives optical signals to and from the reflector to determine the angular position of the shaft 155. It is contemplated that other methods of determining angular position may be utilized, such as using a stepper motor with steps of known angular distances. In another example, the susceptor assembly 124 may be rotated at a constant, specified speed while a stage encoder provides data related to the angular position of the susceptor assembly 124 to the controller 196. The controller 196 directs light from the light source 244 to the substrate at predetermined intervals and associates each data spectrum collected by the sensor 245 with a known angular position of the susceptor assembly 124. In such an example, the trigger for initiating the propagation of light from light source 244 may be omitted, thereby simplifying the hardware and reducing costs.

[0053]

[0058] Step 506 involves collecting reflected light 227 from the reference substrate. A sensor 245, such as a spectrometer, receives the reflected light 227. The sensor converts the received light into spectral data. In step 508, the sensor 245 transmits the spectral data to the controller 196. In step 510, the controller 196 associates the received spectral data with the angular position of the susceptor assembly 124. Because the thickness of the reference substrate is known, inconsistent spectral data (e.g., showing thickness variations that deviate from the known value of the reference substrate) may be due to wobble of the susceptor assembly 124. The controller 196 may determine a correction factor for each angular position of the susceptor assembly 124 to account for the wobble. In this way, when the sensor 245 receives data during processing of a non-reference substrate, the correction factor is applied to the received measurements, improving the accuracy of film thickness measurements by accounting for variations induced by substrate wobble and rotating members.

[0054]

[0059] In step 512, the combination of angular position and spectral data is used to create a data set as a reference for in-situ reflected light measurements. The data set is stored in the controller 196. It is contemplated that the data set may be updated at predetermined intervals, such as when preventative maintenance is performed on the system 101. In some embodiments, machine learning or artificial intelligence may be applied to improve the collection and application of the data set for improved thin film measurements.

[0055]

[0060] The present disclosure contemplates that steps 502-512 of method 500 may be repeated one or more times to improve the collection and application of data correlating the angular position of the susceptor assembly 124 with the received optical signals. According to some embodiments, which may be combined with other embodiments, steps 502-512 are repeated for a second substrate, such as a different reference substrate, to confirm and / or further refine the previously determined correction factors.

[0056]

[0061] During substrate processing, each measurement by sensor 245 is corrected according to the methods described above. Additionally or alternatively, other methods may be employed during substrate processing to account for wobble of the susceptor assembly. In one example, measurements are taken at the same specified angular position, and only at that angular position, thereby improving consistency. In yet another example, measurements may be averaged, or in yet another embodiment, measurements may be plotted and a trend line or other function applied to account for deviations due to wobble. If the wobble produces a sinusoidal curve, a cosine function may be fitted to the data for each wavelength in the spectrum.

[0062] R fit (t)=A cos(2πft+φ)+R ave

[0063] A = amplitude, f = frequency (Hz), φ = phase shift, R ave = average signal level.

[0057]

[0064] In still other examples, it is contemplated that method 500 may be omitted from processing a substrate. In such examples, wobble correction may not be performed. In other examples, measurements may be normalized to reduce errors due to at least rotational motion, machining tolerances, manufacturing limitations, material properties, system wear, and other possible error sources.

[0058]

[0065] The process of 500 can also be implemented by an algorithm, using time to determine the angular position of the susceptor assembly 124. In some embodiments, the process can be retrofitted to an existing processing chamber, and two controllers are used to activate the sensor 245 to measure the angular position of the susceptor 157. The angular position of the susceptor 157 can be determined by a position sensor or by a computer algorithm using variables such as time.

[0059]

[0066] Advantages of the present disclosure include an in-situ, real-time film growth measurement process, accurate film growth monitoring, improved signal-to-noise ratio, use of reduced optical wavelengths, improved measurement resolution, improved efficiency and throughput, reduced machine downtime, and cost savings. Determining the film thickness or growth rate involves measuring multiple light intensity values ​​of reflected light over one or more time intervals. The multiple light intensity values ​​are correlated to reference data or a physical model based on Fresnel's electromagnetic wave reflection equation to determine the growth rate over one or more time intervals. The growth rate can correspond to changes in light intensity over one or more time intervals. The growth rate over a time interval can be used to determine the film thickness. The film thickness data can be used to improve processing. For example, if the growth rate is too high or too low, one or more process parameters can be adjusted to correct the growth rate to a target growth rate. The one or more process parameters can include the flow rate of process gases, the power supplied to the upper and / or lower lamps, the substrate processing temperature, the operating time during which the substrate processing step is performed, and / or the process pressure within the processing space 110.

[0060]

[0067] It is contemplated that one or more aspects disclosed herein may be combined. By way of example, one or more aspects, features, components, and / or characteristics of system 101, processing chamber 100, and ISR system 185 may be combined. Furthermore, it is contemplated that one or more aspects disclosed herein may include some or all of the advantages described above.

[0061]

[0068] In addition to monitoring film growth rate, film thickness, in-film composition concentration, and temperature, it is contemplated that aspects of the present disclosure may be utilized to monitor film composition. For example, in SiGe films, the refractive index and extinction coefficient vary as a function of germanium concentration. Therefore, changes in the refractive index or extinction coefficient measured by sensor 245 may indicate changes in film composition during SiGe formation. Once identified, process conditions within the processing chamber (e.g., temperature, gas flow rate, gas composition, pressure, processing time, etc.) can be adjusted to promote the desired film composition. Iterative measurements and adjustments can be performed to achieve the target result. While this particular example is described with reference to SiGe films, it is contemplated that aspects of the present disclosure may be applied to films of other compositions.

[0062]

[0069] The present disclosure achieves unexpected results because it was thought that measuring film growth during processing in the processing space 110 of the processing chamber would be fraught with inaccuracies resulting from the use of light emitted from lamps to heat the upper and lower domes and / or the substrate. The present disclosure achieves the aforementioned advantages over processes that perform film measurements on substrates after the substrate has been processed and removed from the processing chamber.

[0063]

[0070] The present disclosure contemplates that terms such as "couples," "coupling," "couple," and "coupled" may include, but are not limited to, fastening such as by welding, interference fitting, and / or using bolts, threaded connections, pins, and / or screws. The present disclosure contemplates that terms such as "couple," "coupling," "couple, coupling," and "coupled" may include, but are not limited to, integral formation. The present disclosure contemplates that terms such as "couple," "coupling," "couple, coupling," and "coupled" may include, but are not limited to, direct coupling and / or indirect coupling. The present disclosure contemplates that terms such as "couple," "coupling," "couple, coupling," and "coupled" may include operative coupling such as electrical coupling and / or fluid coupling.

[0064]

[0071] This disclosure contemplates that terms such as "send," "sending," "transmits," "directs," and "reflecting" light may include, but are not limited to, incident light, collimated light, light in an optical cable, light in an optical wire, full spectrum light, and / or wavelength filtered light. This disclosure contemplates that terms such as "transparent" and / or "opaque" may include, but are not limited to, the property of a material to fully and / or partially transmit light.

[0065]

[0072] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof. The present disclosure also contemplates that one or more aspects of the embodiments described herein may be substituted for one or more of the other aspects described. The scope of the present disclosure is determined by the following claims.

Claims

1. 1. A method for calibrating the rotation of a support, comprising: rotating a substrate support disposed within a processing chamber; directing light into the processing chamber; collecting the reflected light; and determining spectral data from the reflected light; and associating the spectral data with one or more angular positions of the substrate support; determining at least one correction factor for the one or more angular positions based on the spectral data; and A method comprising:

2. The reflected light is collected while a first substrate is supported on the substrate support, and the method includes: replacing the first substrate with a second substrate; measuring a parameter while the second substrate is rotated on the substrate support; applying said correction factor to said parameters to account for wobble of said substrate support; The method of claim 1 further comprising:

3. The method of claim 2 , wherein the parameter is measured during the deposition process.

4. The method of claim 1 , wherein the light is directed toward the substrate support at the one or more angular positions of the substrate support.

5. The method of claim 1 , wherein the directing of the light occurs at intervals related to the one or more angular positions of the substrate support.

6. The method of claim 1 , wherein the light is directed in response to a controller instruction or in response to a physical trigger.

7. The method of claim 1 , wherein the light is directed at a known intensity and a known wavelength.

8. 2. The method of claim 1, wherein determining the correction factor comprises determining where the spectral data deviates from known data of at least one of a surface reflectance, a refractive index, or an extinction coefficient.

9. The method of claim 1 , wherein one or more of the wavelength or intensity of the spectral data is associated with the one or more angular positions.

10. 1. A method for calibrating the rotation of a support, comprising: rotating a substrate support disposed within a processing chamber; directing light toward the substrate support and a preheat ring disposed outside the substrate support; collecting the reflected light; and determining spectral data and reference data from the reflected light; associating the spectral data with one or more angular positions of the substrate support; A method comprising:

11. The substrate support is rotated with a substrate supported thereon, the spectral data corresponding to the reflected light reflected from the substrate, and the method comprises: comparing the spectral data with the reference data to determine a thickness of the film deposited on the substrate; The method of claim 10 further comprising:

12. The method of claim 10 , wherein the reference data corresponds to the reflected light reflected from a coupon supported on the preheat ring.

13. determining a correction factor for at least one of the one or more angular positions where the spectral data deviates from the reference data; applying said correction factor to the measured parameters to account for wobble of said substrate support; The method of claim 12 further comprising:

14. directing light to the second substrate during a second film deposition process; collecting the light reflected from the second substrate during the second film deposition process; generating second spectral data from the light reflected from the second substrate during the second film deposition process; comparing the spectral data, the second spectral data, and the reference data to determine at least one of a wobble of the substrate support or a thickness of a film deposited on the second substrate; and The method of claim 11 further comprising:

15. The method of claim 11 , wherein the substrate support is rotated at a constant speed and the collecting of the light occurs at regular intervals.

16. The method of claim 11 , wherein said collecting said light comprises receiving said light with a spectrometer.

17. 1. A system for semiconductor manufacturing, comprising: a processing chamber; A light source and a substrate support disposed within the processing chamber and coupled to a translation assembly, the translation assembly configured to rotate the substrate support; and A sensor, A controller comprising instructions that, when executed, cause a plurality of steps to be performed, the plurality of steps comprising: rotating the substrate support; directing light from the light source into the processing chamber; collecting reflected light with the sensor; determining spectral data from the reflected light; and associating the spectral data with one or more angular positions of the substrate support; Including the controller and A system comprising:

18. The reflected light is collected while a first substrate is supported on the substrate support, and the steps include: determining at least one correction factor for the one or more angular positions based on the spectral data; replacing the first substrate with a second substrate; measuring a parameter during a deposition process and while the second substrate is rotated on the substrate support; applying said correction factor to said parameters to account for wobble of said substrate support; 20. The system of claim 17, further comprising:

19. 20. The system of claim 18, wherein the sensor is a spectrometer and determining the correction factor comprises determining where the spectral data deviates from known data, the known data comprising a known thickness of the first substrate.

20. 20. The system of claim 17, further comprising a position sensor configured to transmit the one or more angular positions of the substrate support to the controller to associate the spectral data with the one or more angular positions.

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