Temperature calibration with deposition and etch process

Abstract

A method and apparatus for correcting the temperature within a processing chamber are described. The method includes determining an etching rate of a layer within the processing chamber. The processing chamber is a deposition chamber configured for use during semiconductor manufacturing. The etching rate is used to determine the temperature within the processing chamber. This temperature within the processing chamber is then compared to a correction temperature to determine a temperature deviation. The etching rate is determined using any one of a pyrometer, reflectometer, camera, or quality sensor.

Description

Technical Field

[0001] The embodiments disclosed herein generally relate to a method and apparatus for calibrating the temperature of a processing chamber. More specifically, this application relates to a non-contact method for calibrating the temperature of a semiconductor processing chamber. Prior Technology

[0002] Semiconductor substrates are processed for a variety of applications, including the fabrication of integrated devices and microdevices. During processing, the substrate is positioned on a substrate support within a processing chamber. The substrate support is supported by a support shaft that can rotate about a central axis. Precise control of the heating source, such as multiple heating lamps positioned below and above the substrate, allows the substrate to be heated within very tight tolerances. The temperature of the substrate affects the uniformity of the material deposited on it.

[0003] Over time, aging of the heat source and film buildup on the inner surfaces of the processing chamber reduce the accuracy and precision of heating within the chamber. During preventative maintenance, the processing chamber can be manually recalibrated periodically to improve heating accuracy and precision. Recalibrating the processing chamber results in extended downtime. Extended downtime leads to reduced throughput and increased ownership costs. Recalibration methods generally also utilize substrates or additional equipment removed from the processing chamber after recalibration. Additional test substrates and / or equipment further increase the cost of performing calibration routines.

[0004] Therefore, there is a need for improved equipment and methods for recalibrating the temperature inside the processing chamber. Summary of the Invention

[0005] This disclosure generally relates to a method for calibrating the temperature of a processing chamber. The method is applicable to semiconductor manufacturing. The method includes performing a first procedure. The first procedure further includes (a) allowing gas to flow into the processing chamber while the processing chamber is at a first pressure; (b) setting the temperature of a substrate support within the processing chamber to a first temperature; (c) depositing a first layer of film having a first thickness on the substrate support using the gas; (d) etching the first layer of film from the substrate support at the first temperature; (e) determining an etching rate for etching the first layer at the first temperature; and (f) storing the etching rate relative to the first temperature as a first temperature etching rate. The method further includes repeating each of (a)-(f) at a second temperature different from the first temperature to obtain a second temperature etching rate. A measured temperature profile is determined based at least on the first temperature etching rate and the second temperature etching rate. The measured temperature profile is compared with a calibration temperature profile.

[0006] In another embodiment, a method for determining the temperature of a processing chamber is described. This method is applicable to semiconductor manufacturing. The method includes performing a first procedure. The first procedure includes (a) allowing gas to flow into a processing volume; (b) setting the temperature of a substrate support within the processing volume to a first temperature; (c) depositing a first layer having a first thickness on the substrate support using the gas; (d) etching the first layer from the substrate support at the first temperature to a second thickness less than the first thickness; and (e) determining a first temperature etch rate for etching the first layer at the first temperature using one or more pyrometers, one or more cameras, one or more strain gauges, or one or more piezoelectric sensors. The method further includes repeating each of operations (a)-(e) within the first procedure at a second temperature different from the first temperature to obtain a second temperature etch rate. The method further includes determining a measurement temperature profile based at least on the first temperature etch rate and the second temperature etch rate.

[0007] In another embodiment, a non-transitory computer-readable medium is described. This non-transitory computer-readable medium stores instructions that, when executed by a processor, cause a computer system to operate. The operation includes performing a first procedure. The first procedure includes (a) allowing gas to flow into a processing volume; (b) setting the temperature of a substrate support within the processing volume to a first temperature; (c) depositing a first layer having a first thickness on the substrate support using the gas; (d) etching the first layer from the substrate support at the first temperature to a second thickness less than the first thickness; and (e) determining a first temperature etch rate for etching the first layer at the first temperature using one or more sensors. The instructions further include repeating each of operations (a)-(e) within the first procedure at a second temperature different from the first temperature to obtain a second temperature etch rate. The instructions further include determining a measurement temperature profile based at least on the first temperature etch rate and the second temperature etch rate. Simple Explanation of the Diagram

[0008] To gain a more detailed understanding of the features described above, a more specific description of the present disclosure 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 only illustrate exemplary embodiments and should therefore not be considered as limiting the scope, as 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] Figures 2A-2C show schematic cross-sectional views of a portion of a substrate support according to one embodiment.

[0011] Figure 3 illustrates a method for correcting the temperature of the deposition chamber in Figure 1 according to one embodiment.

[0012] Figure 4 is a graph showing the temperature curve and the corresponding etching rate.

[0013] Figures 5A and 5B are graphs showing the changes in wavelength intensity during the layer growth and layer etching processes.

[0014] For ease of understanding, the same element symbols are used to denote common elements in the figures where possible. It is contemplated that elements and features of one embodiment can be advantageously incorporated into other embodiments without further description. Implementation

[0015] This disclosure generally relates to a method and apparatus for calibrating the temperature of a processing chamber. More specifically, the method relates to calibrating the temperature of a semiconductor processing chamber used for epitaxial deposition, but is also contemplated for use in other chambers. The method utilizes measurements of the etching rate to determine the temperature of the processing chamber. For some temperatures, the growth rate of layers on the substrate and / or substrate support is not readily correlated with the temperature of the substrate support or the processing chamber. However, it has been found that the etching rate of layers within the processing chamber can be used to determine the temperature within the processing chamber.

[0016] The etching rate depends on the temperature of the substrate support and the processing chamber over a wide temperature range. The etching rate can be used at temperatures below or above 1000°C. The temperature correction method described herein can be used in a temperature range from 500°C to approximately 1500°C. Utilizing the etching rate of the film formed on the substrate support to determine temperature and / or temperature drift further enhances the accuracy of temperature measurements by reducing or eliminating the influence of variables such as coating formation on windows, substrate support aging, or pyrometer drift.

[0017] The method of determining temperature using the etching rate can be automated and does not require the use of a substrate during calibration. Therefore, the temperature determination method can be performed multiple times at different temperatures, and the temperature profile can be estimated based on data points. The temperature profile can be compared with the calibration temperature profile. The calibration temperature profile is a predetermined profile derived from historical data from the baseline calibration chamber and / or the chamber currently in use.

[0018] By comparing the temperature profile determined using the etch rate with the calibration temperature profile, the calibration factor for one or both of the temperature sensor and heat source can be determined. If, after applying the calibration factor, the temperature profile still exceeds the set tolerance range around the calibration temperature profile, an error is reported, and potential causes of errors in other components and / or process inputs are evaluated.

[0019] Figure 1 is a schematic diagram of a type of processing chamber 100 according to an embodiment of this disclosure. The processing chamber 100 is a semiconductor processing chamber and may be a deposition chamber. The processing chamber 100, as described herein, is used to grow an epitaxial film on a substrate (not shown). The processing chamber 100 generates cross-flow of precursors on the top surface of the substrate.

[0020] The processing 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. The chamber body contains a substrate support 106, an upper dome 108, a lower dome 110, a plurality of upper lamps 141, and a plurality of lower lamps 143.

[0021] As shown, controller 120 communicates with processing chamber 100 and is used to control processes, such as those described herein. Controller 120 includes a central processing unit (CPU) 159, memory device 135, and support circuitry 158. Controller 120 can directly control processing chamber 100 or be controlled via another computer or controller (not shown) associated with specific support system components. Controller 120 can be one of any type of general-purpose computer processor, which can be used in an industrial environment to control various chambers and subprocessors. Memory 135 or computer-readable media can be one or more of readily available memories, such as random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, flash drive, or any other form of digital storage, whether local or remote. Support circuitry 158 is coupled to CPU 159 to support the processor in a conventional manner. Support circuitry 158 includes cache memory, power supply, clock circuitry, input / output circuitry systems, and subsystems. The processing steps can be stored as software routines in memory 135, which can be executed or triggered to turn controller 120 into a purpose-specific controller to control the operation of processing chamber 100. Controller 120 can be configured to perform any of the methods described herein.

[0022] A substrate support 106 is disposed between an upper dome 108 and a lower dome 110. A plurality of upper lamps 141 are disposed between the upper dome 108 and a cover 154. The cover 154 includes a plurality of sensors 153, 155 disposed therein for measuring the temperature within the processing chamber 100. A plurality of lower lamps 143 are disposed between the lower dome 110 and a base plate 152. The plurality of lower lamps 143 form a lower lamp assembly 145. Each of the plurality of sensors 153, 155 may be a camera, a pyrometer, or a reflectometer. One of the sensors 153, 155 is a calibration sensor 155. The calibration sensor 155 is configured to assist the temperature calibration method described herein. Other sensors, such as sensor 153, are pyrometers and are configured to measure the temperature of the top surface of the substrate.

[0023] At least one lower calibration sensor 149 is disposed through the base plate 152 of the processing chamber 100. Calibration sensor 149 is similar to calibration sensor 155. Calibration sensor 149 faces the bottom surface of the substrate support 106.

[0024] A processing volume 136 is formed between an upper dome 108 and a lower dome 110. The processing volume 136 has a substrate support 106 disposed therein. The substrate support 106 includes a top surface 202 on which a substrate is disposed (Figures 2A-2C). The substrate support 106 is attached to a shaft 118. This shaft is connected to a motion assembly 121. The 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 processing volume 136. The motion assembly 121 includes a rotary actuator 122 that rotates the shaft 118 and / or the substrate support 106 about a longitudinal axis A of the processing chamber 100. The motion assembly 121 further includes a vertical actuator 124 to raise and lower the substrate support 106 in the z-direction. The motion assembly includes a tilt adjustment device 126 for adjusting the planar orientation of the substrate support 106 and a lateral adjustment device 128 for adjusting the position of the left and right adjustment axis 118 and the substrate support 106 in the processing volume 136.

[0025] 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 from the substrate support 106 before or after performing a deposition process. When the substrate support 106 descends from the processing position to the transport position, the lifting pin 132 may rest on a lifting pin stop 134.

[0026] Mass sensor 160 is coupled to shaft 118 of substrate support 106, as appropriate. Mass sensor 160 is configured to measure the mass and / or weight of substrate support 106 and / or coating thickness on substrate support 106. Mass sensor 160 may be a strain gauge or a piezoelectric sensor. The strain gauge may be an optical strain gauge or an electrical strain gauge. Mass sensor 160 is disposed below shaft 118 such that at least a portion of the mass of substrate support 106 is supported by mass sensor 160. Mass sensor 160 is disposed below a bearing, such as a ball bearing assembly. The ball bearing assembly is configured to support at least a portion of the weight of substrate support 106 and is disposed between mass sensor 160 and shaft 118 of substrate support 106.

[0027] The flow module 112 includes a plurality of process gas inlets 114, a plurality of purge gas inlets 164, and one or more exhaust outlets 116. The plurality of process gas inlets 114 and the plurality of purge gas inlets 164 are disposed on the side of the flow module 112 opposite to the one or more exhaust outlets 116. One or more flow deflectors 146 are disposed below the plurality of process gas inlets 114 and the one or more exhaust outlets 116. The flow deflectors 146 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 of a substrate (not shown) disposed within the processing volume 136. The process gas inlets 114 are fluidly connected to a process gas source 151. The purge gas inlets 164 are fluidly connected to a purge gas source 162. One or more exhaust outlets 116 are fluidly connected to exhaust pump 157. Each of the processed gas source 151 and the purified gas source 162 may be configured to supply one or more precursors or processed gases to the processing volume 136.

[0028] Figures 2A-2C show schematic cross-sectional views of a portion of the substrate support 106. As shown in Figure 2A, the substrate support 106 has a top surface 202. The top surface 202 may be configured to hold a substrate (not shown). During the growth and etching rate methods described herein, the top surface 202 does not include the substrate disposed thereon. The substrate support 106 is a quartz, silicon carbide, or graphite-coated material, but other materials are also contemplated. The top surface 106 of the substrate support 106 is configured to reflect radiation of a specific wavelength, such that a radiation beam 206 is reflected as a total internal reflection beam 208 away from the top surface 202. Some of the radiation beam 206 may be absorbed by the substrate support 106.

[0029] In an embodiment where the calibration sensor 155 is a pyrometer, a radiation beam 206 may be output by the calibration sensor 155. The calibration sensor 155 is configured to receive and measure the intensity of the total internal reflection radiation beam 208. The wavelength of the radiation beam 206 emitted by the calibration sensor 155 has a band less than about 3700 nm, such as a band less than about 3300 nm, such as a band less than about 2000 nm, such as a band less than about 400 nm. Therefore, the total wavelength range emitted by the calibration sensor 155 is less than about 3700 nm, such as less than about 3300 nm, such as less than about 2000 nm. The wavelength of the radiation beam 206 emitted by the calibration sensor 155 is from about 400 nm to about 3700 nm, such as from about 500 nm to about 3000 nm, such as from about 1000 nm to about 2500 nm.

[0030] As described with respect to method 300 of Figure 3, layer 204 is deposited onto the top surface 202 of substrate support 106 (Figure 2B). Layer 204 is grown to a first thickness T1. The first thickness T1 is about 400 nm to about 5500 nm, such as about 500 nm to about 5000 nm, such as about 500 nm to about 3000 nm. Other thicknesses may also be considered depending on the gas flow rate, concentration, and precursor material. Layer 204 can be described as a first layer or coating on substrate support 106. In some embodiments, a separate protective coating (not shown) is formed on substrate support 106 prior to the deposition of layer 204 on substrate support 106. Layer 204 is a silicon-containing layer or a germanium-containing layer. In some embodiments, layer 204 is a silicon layer, such as a polycrystalline silicon layer, and is formed using one or a combination of silane (SiH4), disilane (Si2H6), trisilane (Si3H8), chlorosilane (SiH3Cl), dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), and tetrachlorosilane (SiCl4). In some embodiments, only one precursor is used, thereby making it easier to control the film growth and etching rates. In other embodiments, additional precursors may be combined with silicon-containing precursors so that layer 204 has desired properties, such as desired reflectivity, absorptivity, growth rate, and / or etching rate. As described herein, the material and thickness of layer 204 are configured to be measurable by one or more calibration sensors 155. In embodiments where the calibration sensor 155 is a camera, the emissivity of layer 204 is measured. In embodiments where the calibration sensor 155 is a pyrometer and / or reflectometer, the intensity of different wavelengths reflected by layer 204 is measured.

[0031] As shown in Figure 2B, layer 204 reflects the first reflected radiation beam 212 away from layer surface 205. Layer surface 205 is the top surface of layer 204. The first reflected radiation beam 212 is a portion of radiation beam 206. Transmitted radiation beam 211 continues through layer 204 and is a second portion of radiation beam 206, not reflected as the first reflected radiation beam 212. Transmitted radiation beam 211 passes through layer 204, and at least a portion of transmitted radiation beam 211 is reflected away from the top surface 202 of substrate support 106 as a second reflected radiation beam 210. The second reflected radiation beam 210 can be combined with the first reflected radiation beam 212 and undergo constructive or destructive interference. The constructive or destructive interference can be measured over time to determine the thickness of deposited layer 204 (based on the wavelength of the calibration sensor 155, the material properties of layer 204, and the measured constructive / destructive interference). The thickness of layer 204 helps determine the growth rate and etching rate of layer 204.

[0032] Figure 2C shows a portion of the substrate support 106 after a portion of layer 204 has been etched. The etched layer 204 has a second thickness T2. As described in method 300, the difference between a first thickness T1 and a second thickness T2 is measured to determine the etching rate of layer 204. In one example, the entire layer 204 is removed during etching.

[0033] Figure 3 illustrates a method 300 for calibrating the temperature of a processing chamber (e.g., processing chamber 100 in Figure 1). A similar method 300 can also be used for other types of processing chambers. Method 300 is performed without a substrate within processing chamber 100. Method 300 can be stored and executed by controller 120, such that memory 135 stores method 300 and method 300 is executed by CPU 159. Method 300 utilizes the growth and etching of layers such as layer 204 on a substrate support, such as substrate support 106, to determine the temperature of the processing chamber, and can therefore be used to calibrate temperature measurement devices inside the processing chamber.

[0034] Method 300 includes operation 302 of correcting the airflow entering the processing chamber and the pressure within the processing volume of the processing chamber (such as processing volume 136). Airflow correction may include correcting one or both of a deposition gas and a purging gas. The deposition gas is the gas used to deposit layer 204 onto a substrate support. The purging gas is the gas used to etch layer 204 from the substrate support. Airflow correction is performed to achieve accurate flow rates and accurate gas / precursor concentrations entering the processing volume. Accurate flow rates and gas / precursor concentrations improve the accuracy of method 300 by reducing potential sources of error. The flow rates and gas / precursor concentrations are corrected to a tolerance window of less than about 5%, such that the flow rates and gas / precursor concentrations are within ±5% of the desired flow rates and / or gas / precursor concentrations. In some embodiments, the flow rate and gas / precursor concentration are corrected to be within a tolerance window of less than about 3%, such as less than about 2%, such as less than about 1%, such as less than about 0.5%.

[0035] Similarly, the pressure within the processing volume is corrected such that it is within a tolerance window of less than about 5% of the desired processing pressure. In some embodiments, the pressure is within a tolerance window of less than about 3%, such as less than about 2%, such as less than about 1%, such as less than about 0.5%. Accurate pressure within the processing volume improves the accuracy of method 300 by reducing potential sources of error.

[0036] Once the pressure, flow rate, and gas / precursor concentration have been corrected during operation 302, the first process begins. The first process includes operation 304 setting the temperature of one or both of the processing volume and the substrate support to a first temperature. During the first process, the processing volume and the substrate support are maintained at the first temperature. Setting the temperature to the first temperature includes heating and / or cooling the substrate support and the processing volume using one or more lamps and / or heaters arranged within the substrate support. The first temperature may be greater than or less than about 1000°C. In some embodiments, the first temperature is from about 500°C to about 1500°C, such as from about 600°C to about 1300°C, such as from about 800°C to about 1000°C. In some embodiments, the first temperature is greater than 1000°C, such as greater than about 1100°C. It has been found that the growth rate of the layer can be used to determine temperatures, such as temperatures below about 1000°C. However, the growth rate at high temperatures (such as growth at temperatures above about 1000°C) is independent of temperature and therefore difficult to determine based on the growth rate. For example, at temperatures above approximately 1000°C, membrane growth often depends on mass transfer rather than temperature.

[0037] Once the temperature and processing volume of the substrate support have been set to a first temperature, another operation 306 is performed. Operation 306 includes coating the substrate support within the processing chamber with a layer such as layer 204. This layer is a silicon-containing or germanium-containing layer. The layer grows to a first thickness T1 within a first time period. Layer growth is performed for a predetermined first time period, or until the desired first thickness T1 is reached. In embodiments where layer growth is performed for a predetermined first time period, the first thickness T1 varies slightly between operations of the processing chamber. In embodiments where the layer grows to the first thickness T1, the first time period varies slightly between each operation of the processing chamber. In some embodiments, the layer is a silicon layer and uses one or a combination of silane (SiH4), disilane (Si2H6), trisilane (Si3H8), chlorosilane (SiH3Cl), dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), and tetrachlorosilane (SiCl4). In one example, the processing chamber is configured to use the same gas to process the substrate and deposit layer 204, thereby simplifying the calibration process. Other precursors can be combined with silicon-containing precursors to give the layer desired properties, such as desired reflectivity, absorptivity, growth rate, and / or etch rate.

[0038] As described herein, the material and thickness of the layer are configured to be measurable by one or more calibration sensors, such as calibration sensor 155 or mass sensor 160. A first thickness T1 of the layer is determined during operation 306. The first thickness T1 is determined using one of several different measurement techniques. These techniques include a first thickness determination method using a camera and a calibrated growth process. A second thickness determination method utilizes a pyrometer and / or reflectometer to measure the constructive / destructive interference of the growing layer. A third thickness determination method utilizes a mass sensor (such as a strain gauge or piezoelectric sensor) to determine the coating thickness on the substrate support. It is contemplated that one or more of the first, second, or third thickness determination methods may be used.

[0039] The first thickness determination method determines the first thickness T1 by performing a calibrated growth process. The calibrated growth process is a process performed under predetermined time and predetermined processing conditions. The calibrated growth process has been pre-calibrated so that the first thickness T1 can be accurately estimated by performing the calibrated growth process under predetermined processing conditions and time. Calibration is performed during previous operations or maintenance procedures. The calibration process involves layer growth on a substrate under predetermined processing conditions and time. The layer thickness is then measured using one or more methods. Layer thickness measurement can be performed using contact thickness measurement or non-contact thickness measurement. Contact thickness measurement can be performed manually or automatically.

[0040] Once the thickness of the layer grown during the calibration process is known, the calibration growth process is performed, and it is assumed that the layer has a similar thickness for each repetition of the calibration growth process. Therefore, it is assumed that the first thickness T1 is the same as the layer thickness measured during the calibration process.

[0041] The second method for determining the thickness involves measuring interference signals during layer growth using a pyrometer and / or reflectometer. Therefore, the first thickness T1 is determined by monitoring the constructive / destructive interference of reflected radiation during deposition. One or more calibration sensors, such as one or a combination of a pyrometer and a reflectometer, can be used to determine the first thickness T1.

[0042] A pyrometer and / or reflectometer measures the growth of the layer over time by recording the intensity of certain wavelengths of the radiation beam as it is reflected away from the top surface of the substrate support and the layer described in Figure 2B. Due to constructive and destructive interference caused by variations in layer thickness, the intensity may form an oscillating curve. Based on the known wavelengths of the calibration sensor 155 and the measured oscillations, the thickness of layer 204 can be determined.

[0043] Figure 5A is an illustration of a graph 500 that can be used to determine the first thickness T1 using a pyrometer and / or reflectometer. The graph 500 measures radiation intensity over time, such that the intensity measurement begins at a first time t0 and ends at a second time t1. The first time t0 is the initial measurement start time or the initial recording start time. The second time t1 is the end measurement time or the final recording time. As seen in the upper portion 502 of the graph 500, one or more pyrometers and / or reflectometers are used to measure the first intensity curve L1 and the second intensity curve L2. The first intensity curve L1 is the radiation intensity reflected from the top surface of the substrate support and the layer. The first intensity curve L1 is measured using a pyrometer and / or reflectometer (e.g., calibration sensor 155) positioned above the substrate support. The pyrometer and / or reflectometer is configured to have a narrow measurement bandwidth to reduce interference from other stray radiation within the processing chamber. The intensity of the first intensity curve L1 changes over time as the layer grows on the substrate support. The time-varying intensity is attributed to the fact that the radiation beam reflected from the substrate support changes from constructive interference to destructive interference as the thickness of layer 204 increases, and vice versa.

[0044] The second intensity curve L2 represents the radiation intensity reflected from the bottom surface of the substrate support. The second intensity curve L2 is measured using a pyrometer and / or reflectometer positioned below the substrate support, such as a lower calibration sensor 149. The pyrometer and / or reflectometer is configured to have a narrow measurement bandwidth to reduce interference from stray radiation within the processing chamber. The intensity of the second intensity curve L2 appears relatively constant at a first intensity I1. The first intensity I1 is largely constant because the layer does not grow on the bottom surface of the substrate support, and therefore there is no constructive interference caused by layer growth. However, as the first intensity curve L1 oscillates between constructive interference and constructive interference, the first intensity curve L1 varies between a second intensity I2 and a third intensity I3.

[0045] The difference between each of the first intensity curve L1 and the second intensity curve L2 is used to obtain the third intensity curve L3, as shown in the lower part 504 of graph 500. The second intensity curve L2 is used as a baseline intensity curve, thereby removing variations caused by factors other than the deposited layer on the substrate support from the first intensity curve L1. Therefore, the intensity of the third intensity curve L3 is the intensity difference between the first intensity curve L1 and the second intensity curve L2. The period P of the third intensity curve L3 can be determined. The number of periods P can be used to determine the total thickness of the layer grown on the substrate support. Therefore, a pyrometer and / or reflectometer can be used to determine the thickness (and correspondingly, the growth rate if the deposition time is tracked).

[0046] The third thickness determination method utilizes a mass sensor, such as mass sensor 160, to determine the first thickness T1. The mass sensor can be one or more strain gauges or piezoelectric sensors. In embodiments using a mass sensor such as mass sensor 160, the weight of the substrate support is measured to determine the growth rate and total thickness of the layer grown during operation 306. The mass sensor can be an optical strain gauge or a piezoelectric sensor. The difference between the mass of the substrate support at the start of operation 306 and the mass at the end of operation 306 is measured. The mass at the start of operation 306 and the mass at the end of operation 306 are compared to determine the layer growth rate and total thickness. Comparing the mass at the start of operation 306 and the mass at the end of operation 306 includes finding the difference between the initial and final mass of the substrate support. The growth distribution on the substrate support can be approximated using a model, or it can be assumed that the growth distribution on the substrate support is uniform. During the growth of the layer on the substrate, periodic additional mass measurements can be performed to generate a growth rate profile.

[0047] Once the layer has grown to a desired thickness, such as a first thickness T1, on the substrate support, layer growth ceases. The layer may also grow for a desired amount of time, such as a first time period, after which the layer thickness is measured. Once layer growth on the substrate support has ceased, another operation 308, etching the layer from the substrate support, is performed. During operation 308, the etching process includes a cleaning process of the inner surface of the processing volume 136. The cleaning process includes introducing an etchant or cleaning gas into the processing volume. The cleaning gas flows into the processing volume and passes over the top surface of the substrate support to etch the layer previously grown on the substrate support. During the etching process in operation 308, the temperature of the processing volume and / or the substrate support is maintained at a first temperature.

[0048] The etchant and / or cleaning gas includes chlorine-containing, hydrogen-containing, and / or fluorine-containing gases. In some embodiments, one or a combination of boron trichloride (BCl3), chlorine (Cl2), ethane (C2F6), carbon tetrafluoride (CF4), octafluoropropane (C3F8), octafluorocyclobutane (C4F8), fluoroform (CHF3), difluoromethane (CH2F2), hydrogen bromide (HBr), hydrogen chloride (HCl), ammonia (NH3), hydrogen fluoride (HF), nitrogen trifluoride (NF3), or sulfur hexafluoride (SF6) is used. In some embodiments, hydrogen chloride (HCl) or Cl2 is used.

[0049] The etching rate of operation 308 is determined during and / or after etching the layer on the substrate support during operation 308. One or more sensors disposed within the processing chamber can be used to determine the etching rate. In some embodiments, one or more calibration sensors (such as a camera, pyrometer, or reflectometer, or a combination thereof) can be used to determine the second thickness T2 or the etching rate. Alternatively, a mass sensor can be used to determine the second thickness T2 or the etching rate. The mass sensor can be one or more strain gauges or piezoelectric sensors. In some embodiments, the second thickness T2 is approximately 0 nm, such that the layer is completely etched from the substrate support.

[0050] The etching rate of a layer on a substrate support is measured using one or more of a first etching measurement method, a second etching measurement method, or a third etching measurement method. The first etching measurement method uses the measured emissivity of the substrate support and a known first thickness T1 to determine the etching rate. The second etching measurement method uses a pyrometer and / or reflectometer to measure the intensity of radiation reflected from the substrate support. The third etching measurement method uses a mass sensor (such as a strain gauge or piezoelectric sensor) to determine the mass change of the substrate support and the corresponding etching rate.

[0051] During the first etching measurement method, the calibration sensor 155 is a camera configured to measure the emissivity of the substrate support. A first thickness T1 is obtained by performing one of the procedures previously described herein. In some embodiments, the first thickness T1 is obtained from a first thickness determination method. In other embodiments, the first thickness T1 is obtained from either a second or a third thickness determination method. The camera is configured to measure the emissivity of the substrate support and / or layers disposed on the substrate support. Although layers are disposed on the substrate support, the emissivity of the layers may vary slightly, but generally remains within a first range of the first value.

[0052] When the layer has been removed and at least a portion of the substrate support is exposed, the emissivity changes abruptly to a second value outside the first range. Whether the emissivity jump leads to a higher or lower emissivity depends at least in part on the wavelength measured by the camera, the material of the layer, and the material of the substrate support. The emissivity jump and the time at which the jump occurs are recorded. The recording time of the emissivity jump can be subtracted from the start time to obtain the etching time. The first thickness T1 is divided by the etching time to obtain the etching rate using the first etching measurement method during operation 310. In some embodiments, the layer is a silicon layer and the substrate support is aluminum, such that the jump between the emissivity of silicon and aluminum is recorded as the etching time.

[0053] During the second etching measurement method, the pyrometer and / or reflectometer layer is removed over time. Layer removal is determined by recording the intensity of certain wavelengths of the radiation beam as it reflects off the top surface of the substrate support and the layer described in Figure 2B. Due to constructive and destructive interference caused by variations in layer thickness, the intensity may form an oscillating curve. When the layer is completely removed and the top surface of the substrate support is exposed, a change in measurement intensity can be observed at the detection point. This change in measurement intensity may be similar to the emissivity change measured during the first etching measurement method.

[0054] Figure 5B is an illustration of curve 525 that can be used to determine the etching rate and / or etching endpoint using a pyrometer and / or reflectometer. Curve 525 measures intensity over time, such that the intensity measurement begins at a third time t2 and ends at a fourth time t3. The third time t2 is the initial measurement start time or the initial recording start time. The fourth time t3 is the end measurement time or the final recording time. As seen in the upper part 506 of curve 525, the fourth intensity curve L4 and the fifth intensity curve L5 are measured using one or more pyrometers and / or reflectometers. The fourth intensity curve L4 is the radiation intensity reflected from the top surface and layer of the substrate support. The fourth intensity curve L4 is measured using a pyrometer and / or reflectometer (such as calibration sensor 155) positioned above the substrate support. The pyrometer and / or reflectometer is configured to have a narrow measurement bandwidth to reduce interference from other stray radiation within the processing chamber, thereby improving measurement accuracy. The intensity of the fourth intensity curve L4 changes over time as the layer is etched from the substrate support. The time-varying intensity is attributed to the fact that the radiation beam reflected from the substrate support changes from constructive interference to destructive interference as the layer thickness increases, and vice versa.

[0055] The fifth intensity curve L5 represents the radiation intensity reflected from the bottom surface of the substrate support. The fifth intensity curve L5 is measured using a pyrometer and / or reflectometer positioned below the substrate support, such as a lower calibration sensor 149. The pyrometer and / or reflectometer is configured to have a narrow measurement bandwidth to reduce interference from stray radiation within the processing chamber. The intensity of the fifth intensity curve L5 appears relatively constant at the fourth intensity I4. The fourth intensity I4 is mostly constant because no layer is grown on the bottom surface of the substrate support, and therefore there is no constructive or destructive interference caused by etching of the layer. However, the fourth intensity curve L4 varies between the fifth intensity I5 and the sixth intensity I6 because it oscillates between constructive and destructive interference.

[0056] The difference between each of the fourth intensity curve L4 and the fifth intensity curve L5 is used to obtain the sixth intensity curve L6, as shown in the lower part 508 of curve diagram 525. The fifth intensity curve L5 is used as a baseline intensity curve so that variations caused by factors other than etching the layer on the substrate support can be removed from the fourth intensity curve L4. Therefore, the intensity of the sixth intensity curve L6 is the intensity difference between the fourth intensity curve L4 and the fifth intensity curve L5.

[0057] The sixth intensity curve L6 includes a partially etched portion 510, a detection point 512, and a fully etched portion 514. The partially etched portion 510 is the data acquired when the layer is being etched and its thickness is decreasing. The detection point 512 is the point where the layer is fully etched and the material measured by a pyrometer and / or reflectometer changes from the layer material to the material of the substrate support surface. The fully etched portion 514 is the data acquired after the layer has been fully etched. The time difference between the fourth time t4 (where the detection point 512 is located) and the second time t2 is the total etching time. Using the total etching time and the previously determined total layer thickness, the etching rate of the layer is determined.

[0058] During the third etching measurement method, a mass sensor, such as mass sensor 160, is used. The mass sensor measures the weight or mass of the substrate support during operation 310 to determine the etching rate of the layer. The mass sensor may be an optical strain gauge or a piezoelectric sensor. Although the layer is disposed on the substrate support with a first thickness T1, the mass of the substrate support is a first mass. As the layer is etched, the thickness of the layer decreases to a second thickness T2, which is less than the first thickness T1. The mass of the substrate support when the layer has the second thickness T2 is less than the mass of the substrate support when the layer has the first thickness T1. As the layer is etched, the mass of the substrate support continues to decrease until the layer is completely removed from the substrate support.

[0059] The quality at the start of operation 310 is compared with the quality at the end of operation 310 to determine the etch rate of the layer during operation 310. Additional periodic quality measurements may be performed to generate an etch rate profile. In some embodiments, operation 310 ends during partial etching, resulting in a more uniform etch rate across the entire substrate support between the start and end of operation 310.

[0060] After the etch rate is determined during operation 310, the etch rate relative to a first temperature is stored during operation 312. The etch rate may be stored in controller 120, such as in memory 135. Storing the first etch rate during operation 312 may mark the end of the first program. After storing the etch rate and the first temperature during operation 312, each of operations 304, 306, 308, 310, and 312 is repeated at a second temperature to determine a second etch rate during the second program. The second temperature is different from the first temperature. In some embodiments, the second temperature is higher than the first temperature. The second temperature may be greater than about 1000°C, such as greater than about 1100°C. Each of operations 304, 306, 308, 310, and 312 may subsequently be performed a third time at a third temperature to determine a third etch rate, a fourth time at a fourth temperature to determine a fourth etch rate, and a fifth time at a fifth temperature to determine a fifth etch rate. Each of operations 304, 306, 308, 310, and 312 can be cycled a predetermined number of times to obtain a desired set of temperature measurements relative to the etching rate within the processing volume. The temperature increment between iterations can be, for example, 10 degrees Celsius or higher, such as 50 degrees Celsius or higher, such as 100 degrees Celsius or higher. Since no substrate is utilized within the processing volume during operations 304, 306, 308, 310, and 312, method 300 can be performed quickly and independently of any processing performed in the connected processing chamber.

[0061] The etch rate and temperature stored during operation 310 are then used to determine the temperature profile 422 for determining the etch rate. The temperature profile is similar to the curve 400 in Figure 4. Curve 400 plots the measured temperature as a dependent variable 402 and the etch rate as an independent variable 404. The etch rates stored during operation 310 are plotted such that the first etch rate at the first temperature is the first point 406. The second etch rate at the second temperature is the second point 408. The third etch rate at the third temperature is the third point 410. The fourth etch rate at the fourth temperature is the fourth point 412. The fifth etch rate at the fifth temperature is the fifth point 414. The sixth etch rate at the sixth temperature is the sixth point 416. The seventh etch rate at the seventh temperature is the seventh point 418. The eighth etch rate at the eighth temperature is the eighth point 420. Each of points 406, 408, 410, 412, 414, 416, 418, and 420 is used to derive the temperature profile 422. Temperature profile 422 is an estimate of the etching rate at any given temperature within a predetermined range. The etching rate depends at least in part on the temperature of the substrate support and the processing area.

[0062] A calibrated temperature profile, similar to temperature profile 422, is stored in controller 120. The calibrated temperature profile can be determined using a fully calibrated processing chamber similar to the one currently being used. Alternatively, the calibrated temperature profile can be based on previous iterations of method 300, such as during the initial configuration of the processing chamber.

[0063] Since processing conditions such as gas flow rate / pressure have been corrected, the corrected temperature profile and temperature profile 422 are compared. Comparing the corrected temperature profile and the temperature profile 422 determined using operation 314 allows for the determination of the temperature offset of temperature profile 422. The temperature offset may be due to aging of components within the processing chamber and / or film buildup on components within the processing chamber, or other processing drift considerations. Once the temperature offset is determined, the temperature offset value is applied to one or more temperature sensors, lamps, or models within the controller during operation 316.

[0064] The temperature offset is configured to reduce the difference between the temperature measured by one or more temperature sensors and the actual temperature. Alternatively, the temperature offset is configured to reduce the difference between the simulated temperature and the actual temperature. The simulated temperature is the temperature of the processing volume and / or substrate support simulated in the processing model. The actual temperature is the actual temperature of the processing volume and / or substrate support during operation within the processing volume. In some embodiments, the temperature offset is used to adjust one or more input parameters of the processing model and / or processing chamber. The one or more input parameters adjusted during operation 316 may be the flow rate of the processing gas, the power applied to one or more heaters and / or lamps, or the pressure within the processing volume. In another example, the temperature offset value is used to correct the temperature reading of a pyrometer within the processing chamber.

[0065] In methods similar to those described above, each of operations 302, 304, 306, 308, 310, 312, 314, and 316 may be repeated as needed to obtain a second temperature profile. The second temperature profile is used to determine whether the temperature deviation has been corrected and / or whether individual processing conditions or chamber components are inaccurate. The second temperature profile is also compared to the corrected temperature profile. If the second temperature profile exceeds a set tolerance range, an error is reported to the controller. In some embodiments, the set tolerance range is an average temperature difference greater than about 2°C, such as greater than about 4°C, such as greater than about 5°C, such as greater than about 10°C. The set tolerance range may be a percentage error in the etching rate or a percentage difference between etching rates. In some embodiments, the set tolerance range is an etching rate with a percentage error greater than about 0.5%, such as greater than about 1%, such as greater than about 2%.

[0066] Following the correction in operation 316, during operation 318, the substrate can be moved into the processing volume and onto a substrate support for processing on the substrate. This process can be a deposition or etching process. In some embodiments, the process is an epitaxial deposition process. The process during operation 318 can be run a plurality of times on a plurality of different substrates. The preceding operations 302, 304, 306, 308, 310, 312, 314, and 316 of method 300 improve the deposition accuracy during operation 318.

[0067] In some embodiments, a modified version of method 300 is performed. In the modified version of method 300, a substrate is disposed on a substrate support 106 and layer 204 is grown and etched from the top surface of the substrate during operations 306, 308.

[0068] Although the foregoing content pertains to embodiments of this disclosure, other and further embodiments of this disclosure may be designed without departing from its basic scope, which is determined by the scope of the appended patent applications.

[0069] 100: Processing Chamber

[0070] 106: Substrate support

[0071] 107: Lifting pin hole

[0072] 108: Upper Dome

[0073] 110: Lower dome

[0074] 112: Flow Module

[0075] 114: Processing gas inlet

[0076] 116: Exhaust outlet

[0077] 118: Axis

[0078] 120: Controller

[0079] 121: Motion Components

[0080] 122: Rotary Actuator

[0081] 124: Vertical Actuator

[0082] 126: Tilting adjustment device

[0083] 128: Lateral adjustment device

[0084] 132: Lifting pin

[0085] 134: Lifting pin stop

[0086] 135: Memory device / Memory

[0087] 136: Processing volume

[0088] 141: Lighting

[0089] 143: Lowering the Light

[0090] 145: Downlight assembly

[0091] 146: Flow deflector

[0092] 148: Lower Main Body

[0093] 149: Lower calibration sensor

[0094] 151: Processing gas sources

[0095] 152: Base Plate

[0096] 153: Sensor

[0097] 154: Cover

[0098] 155: Sensor

[0099] 156: Upper Main Body

[0100] 157: Exhaust pump

[0101] 158: Support Circuit

[0102] 159: Central Processing Unit

[0103] 160: Mass Sensor

[0104] 162: Purified gas source

[0105] 163: Padding

[0106] 164: Purified gas inlet

[0107] 202: Top surface

[0108] 204: Floor

[0109] 205: Surface layer

[0110] 206: Radiation Beam

[0111] 208: Totally Internal Reflected Radiation Beam

[0112] 210: Second reflected radiation beam

[0113] 211: Transmitted radiation beam

[0114] 212: First reflected radiation beam

[0115] 300: Method

[0116] 302: Operation

[0117] 304: Operation

[0118] 306: Operation

[0119] 308: Operation

[0120] 310: Operation

[0121] 312: Operation

[0122] 314: Operation

[0123] 316: Operation

[0124] 318: Operation

[0125] 400: Curve Graph

[0126] 402: Dependent Variable

[0127] 404: Independent Variable

[0128] 406: First point

[0129] 408: Second point

[0130] 410: Third point

[0131] 412: Fourth point

[0132] 414: Fifth point

[0133] 416: Sixth point

[0134] 418: Seventh point

[0135] 420: Point 8

[0136] 422: Temperature Curve

[0137] 500: Curve Graph

[0138] 502: Upper part

[0139] 504:lower part

[0140] 506: Upper part

[0141] 508: Lower part

[0142] 510: Partially etched portion

[0143] 512: Detection Point

[0144] 514: Fully Etched Section

[0145] 525: Curve Graph

[0146] A: Longitudinal axis

[0147] L1: First intensity curve

[0148] L2: Second intensity curve

[0149] L3: Third Intensity Curve

[0150] L4: Fourth Intensity Curve

[0151] L5: Fifth Intensity Curve

[0152] L6: Sixth Intensity Curve

[0153] P: Period

[0154] T1: First thickness

[0155] T2: Second thickness

[0156] X: Direction

[0157] Y: direction

[0158] Z: Direction

Claims

1. A method for calibrating a temperature in a processing chamber, suitable for semiconductor manufacturing, comprising the steps of: performing a first procedure comprising: (a) infusing a gas into a processing volume while the processing volume is at a first pressure; (b) setting a temperature of a substrate support within the processing volume to a first temperature; (c) depositing a first layer of a film on a top surface of the substrate support using the gas, the first layer having a first thickness, wherein the top surface of the substrate support does not include a substrate disposed thereon; (d) etching the first layer of the film from the substrate support at the first temperature; (e) determining an etching rate for etching the first layer at the first temperature; and (f) storing the etching rate relative to the first temperature as a first temperature etching rate; repeating each of steps (a)-(f) at a second temperature different from the first temperature to obtain a second temperature etching rate; determining a measured temperature profile based at least on the first temperature etching rate and the second temperature etching rate; and comparing the measured temperature profile with a calibration temperature profile.

2. The method as described in claim 1, wherein the gas is a silicon-containing gas and the first layer is a silicon-containing layer.

3. The method as described in claim 2, wherein the first layer is etched by introducing an etchant gas.

4. The method as described in claim 1, wherein the step of comparing the measured temperature curve with the calibrated temperature curve further comprises the steps of: determining an average difference between the measured temperature curve and the calibrated temperature curve, and performing a temperature calibration on a temperature sensor in the processing chamber or adjusting an input parameter of the processing chamber.

5. The method as described in claim 4 further comprises the following steps: determining a second measured temperature profile after performing the temperature correction; and comparing the second measured temperature profile with the corrected temperature profile.

6. The method as described in claim 1, wherein the first temperature and the second temperature are greater than about 1000°C.

7. The method as described in claim 1, wherein one or more pyrometers, one or more cameras, one or more strain gauges or one or more piezoelectric sensors are used to determine the etching rate.

8. The method as described in claim 1 further includes the step of: performing a temperature correction on the temperature sensors in the processing chamber or adjusting an input parameter of the processing chamber.

9. The method as described in claim 1, wherein a pyrometer measuring a wavelength of about 400 nm to about 3700 nm is used to determine the etching rate at the first temperature.

10. A method for determining a temperature of a processing chamber, suitable for semiconductor manufacturing, comprising the steps of: performing a first procedure comprising: (a) influxing a gas into a processing volume; (b) setting a temperature of a substrate support within the processing volume to a first temperature; (c) depositing a first layer on a top surface of the substrate support using the gas, the first layer having a first thickness, wherein the top surface does not include a substrate disposed thereon; (d) etching the first layer from the substrate support at the first temperature to a second thickness less than the first thickness; and (e) determining a first temperature etch rate for etching the first layer at the first temperature using one or more pyrometers, one or more cameras, one or more strain gauges, or one or more piezoelectric sensors; repeating each of operations (a)-(e) in the first procedure at a second temperature different from the first temperature to obtain a second temperature etch rate; and determining a measured temperature profile based at least on the first temperature etch rate and the second temperature etch rate.

11. The method as described in claim 10, wherein a flow rate of the gas and a pressure of the processing volume are calibrated before the first procedure is performed.

12. The method as described in claim 10, wherein one or more pyrometers, one or more cameras, one or more strain gauges or one or more piezoelectric sensors are used to determine the first thickness.

13. The method as described in claim 10, wherein the gas is a silicon-containing gas and the first layer is a silicon-containing layer.

14. The method as described in claim 13, wherein the first layer is etched by introducing an etchant gas.

15. The method as described in claim 14, wherein the etchant gas is a hydrogen-containing gas or a chlorine-containing gas.

16. The method as described in claim 15, wherein the etchant gas is a hydrogen chloride-containing gas.

17. The method as described in claim 10, wherein a pyrometer measuring a wavelength of about 400 nm to about 3700 nm is used to determine the first temperature etching rate.

18. A non-transitory computer-readable medium storing instructions, which, when executed by a processor, cause a computer system to perform the following steps: performing a first program comprising: (a) allowing a gas to flow into a processing volume; (b) setting a temperature of a substrate support within the processing volume to a first temperature; (c) depositing a first layer on a top surface of the substrate support using the gas, the first layer having a first thickness, wherein the top surface does not include a substrate disposed thereon; (d) etching the first layer from the substrate support at the first temperature to a second thickness less than the first thickness; and (e) determining a first temperature etch rate for etching the first layer at the first temperature using one or more sensors; repeating each of operations (a)-(e) in the first program at a second temperature different from the first temperature to obtain a second temperature etch rate; and determining a measured temperature profile based at least on the first temperature etch rate and the second temperature etch rate.

19. The media as described in claim 18 further includes the step of: performing a temperature correction on a temperature sensor within a processing chamber or adjusting an input parameter of the processing chamber.

20. The media as described in claim 19 further comprises the following steps: determining a second measured temperature profile after performing the temperature correction; and comparing the second measured temperature profile with a corrected temperature profile.

21. The medium as described in claim 18, wherein one or more pyrometers, one or more cameras, one or more strain gauges or one or more piezoelectric sensors are used to determine the first temperature etch rate.

22. A method for determining a temperature of a processing chamber, suitable for semiconductor manufacturing, comprising the steps of: performing a first procedure comprising: (a) allowing a deposition gas to flow into a processing volume; (b) setting a temperature of a substrate support within the processing volume to a first temperature; (c) depositing a silicon-containing layer having a first thickness on a top surface of the substrate support using the deposition gas, wherein the top surface of the substrate support does not include a substrate disposed thereon; (d) using one or more pyrometers, one or more reflectometers, or both one or more pyrometers and one or more reflectometers, during the deposition of the silicon-containing layer, monitoring constructive interference, destructive interference, or both of the constructive interference and the destructive interference of reflected radiation to determine the first thickness of the silicon-containing layer; (e) using an etching gas to etch the silicon-containing layer from the substrate support to a second thickness less than the first thickness at the first temperature; and (f) determining a first temperature etching rate for etching the silicon-containing layer at the first temperature; Each of operations (a)-(f) in the first procedure is repeated at a second temperature different from the first temperature to obtain a second temperature etching rate; and a measurement temperature profile is determined at least based on the first temperature etching rate and the second temperature etching rate.

23. The method as described in claim 22, wherein the step of determining the first temperature etching rate comprises the following steps: using one or more pyrometers, one or more reflectometers, or both of the one or more pyrometers and one or more reflectometers, during etching the silicon-containing layer, monitoring constructive interference, destructive interference, or both of the constructive interference and the destructive interference of reflected radiation to determine the second thickness of the silicon-containing layer.

24. The method as described in claim 23, wherein a pyrometer measuring a wavelength of about 400 nm to about 3700 nm is used to determine the first temperature etching rate.

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