Temperature verification method of process chamber

Abstract

The invention discloses a temperature calibration method for a process chamber, and belongs to the technical field of semiconductor processing, and the temperature calibration method comprises the steps: obtaining a temperature calibration menu corresponding to a temperature interval where a set value is located based on the set value of the process temperature of the process chamber; controlling the process chamber to perform the process according to the temperature correction menu so as to form an epitaxial layer on the surface of the transparent substrate; if the epitaxial layer has the transparent region and the non-transparent region, determining that the temperature correction menu is a target temperature correction menu corresponding to the process temperature; measuring the radius of the boundary between the transparent area and the non-transparent area; according to the radius where the boundary is located, the target temperature correction menu and the pre-established corresponding relation between the temperature and the radius in the multiple temperature intervals, the theoretical value of the process temperature is determined when the process chamber carries out the process according to the target temperature correction menu; and determining a compensation value corresponding to the set value according to the difference between the theoretical value and the set value. According to the temperature verification method, the stability and the consistency of the epitaxial process can be improved.

Description

Technical Field

[0001] This application belongs to the field of semiconductor processing technology, specifically relating to a method for temperature verification of a process chamber. Background Technology

[0002] Epitaxy is a common process in semiconductor manufacturing. It typically involves depositing an epitaxial layer onto a substrate. The uniformity of the epitaxial layer is an important indicator for evaluating the process performance. It is highly susceptible to the influence of temperature and the amount of reaction source, and these two factors interact with each other. Therefore, in epitaxy, it is necessary to precisely control the relationship between the process temperature of the process chamber and the amount of reaction source.

[0003] However, the accuracy of thermometers is greatly affected by factors such as batch and brand, as well as the cleanliness of the temperature observation window, installation position and angle, etc. This can lead to a difference between the temperature value of the process chamber measured by the thermometer and the actual temperature value of the process chamber. This can have a significant adverse impact on the results of the epitaxial process, resulting in poor stability and consistency of the epitaxial process. Summary of the Invention

[0004] The purpose of this application is to provide a method for verifying the temperature of a process chamber, so as to solve the problem that the stability and consistency of epitaxial processes are relatively poor due to the inability to accurately obtain the temperature of the process chamber.

[0005] This application discloses a method for temperature verification of a process chamber, the temperature verification method comprising:

[0006] Based on the set value of the process temperature of the process chamber, obtain the temperature calibration menu corresponding to the temperature range in which the set value is located;

[0007] The process chamber is controlled to perform the process according to the temperature calibration menu to form an epitaxial layer on the surface of a transparent substrate;

[0008] If the epitaxial layer has transparent and non-transparent regions, then the temperature calibration menu is determined to be the target temperature calibration menu corresponding to the process temperature;

[0009] Measure the radius of the boundary line between the transparent area and the non-transparent area;

[0010] Based on the radius of the dividing line, the target temperature calibration menu, and the pre-established correspondence between temperature and radius in each of the multiple temperature ranges, the theoretical value of the process temperature is determined when the process chamber performs the process according to the target temperature calibration menu.

[0011] Based on the difference between the theoretical value and the set value, the compensation value corresponding to the set value is determined.

[0012] This application discloses a method for temperature calibration of a process chamber. Based on a setpoint for the process temperature of the process chamber, after obtaining a calibration menu corresponding to the temperature range of the setpoint, the method controls the process chamber to perform the process according to the calibration menu to form an epitaxial layer on the surface of a transparent substrate. If the setpoint does not need to be corrected, the process result produced by the process based on the specific setpoint should be the same as the process result produced by the process based on the same temperature standard value. Conversely, the specific circumstances of the process result produced by the process based on the specific setpoint, combined with the correspondence between the process result and the standard temperature value, can also be used to infer whether the setpoint needs to be corrected. Specifically, the process result can be represented by the specific location of the boundary line between the transparent and non-transparent regions in the epitaxial layer, i.e., the radius of the boundary line. Therefore, if the epitaxial layer has transparent and non-transparent regions, the above temperature calibration menu can be considered as the target temperature calibration menu corresponding to the process temperature. Based on this target temperature calibration menu, the target temperature range can be determined. The theoretical value of the process temperature is located in the target temperature range, and there is a corresponding relationship between the theoretical value of the process temperature and the radius of the boundary line between the transparent and non-transparent regions.

[0013] Furthermore, by measuring the radius of the boundary between the transparent and non-transparent regions in the epitaxial layer formed by the process based on the temperature calibration menu corresponding to the set value, and based on the measured radius, the target temperature calibration menu, the target temperature range, and the correspondence between temperature and radius within the temperature range, the theoretical value of the temperature corresponding to that radius can be determined. The difference between this theoretical value and the set value can then be used to determine the compensation value corresponding to the set value. Accordingly, the sum of the set value and the compensation value is the new set value corresponding to the set value. Accordingly, for each process temperature set value within the process temperature range of the process chamber, the sum of the compensation value and each set value can be used as the new set value. To distinguish between historical set values ​​and new set values, this new set value can be denoted as the calibration value.

[0014] Based on the above technical solution, the correspondence between the temperature of the process chamber and the temperature calibration menu can be verified, thereby ensuring that when the process is carried out using the temperature calibration menu with the corresponding relationship and the set temperature, the uniformity of the process results can be relatively good. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0016] Figure 1 This is a schematic flowchart of the temperature verification method disclosed in the embodiments of this application;

[0017] Figure 2 This is a schematic diagram of a specific structure of the epitaxial layer formed in the temperature verification method disclosed in the embodiments of this application.

[0018] Figure label:

[0019] 1 - Transparent area, 2 - Non-transparent area. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0022] like Figure 1 As shown in the illustration, this application discloses a method for temperature verification of a process chamber. This method verifies the process temperature within the process chamber to ensure that, under the same process parameters, the process chamber performs epitaxial processing at this temperature, resulting in relatively good uniformity of the process results. In other words, this application embodiment requires ensuring that a corresponding set of process parameters and process temperature guarantees good uniformity in the epitaxial process results.

[0023] As mentioned above, in epitaxial processes, process uniformity is significantly affected by both process parameters and temperature, and there is a correlation between the two. Therefore, a specific correspondence exists between process parameters and temperature. However, due to various factors, the measurements taken by measuring devices such as pyrometers used to measure and calibrate the temperature of the process chamber may differ from the actual process temperature within the chamber. Consequently, if the process parameters corresponding to the measured values ​​are used, the actual process temperature may not correspond to the selected process parameters, thus reducing the stability and consistency of the epitaxial process results. More specifically, the aforementioned process parameters can be the amount of reaction source used.

[0024] Furthermore, after discovering the aforementioned technical problems, the inventors of this application also found that in epitaxial processes, the thickness and roughness of the epitaxial film vary relatively little within a certain temperature range. Moreover, since doping concentration and defect density are affected not only by temperature but also significantly by other factors, even when the uniformity of the epitaxial process is relatively good, it is impossible to directly determine whether the detected temperature of the process chamber differs from the actual temperature based on the actual conditions of these parameters when using testing equipment to accurately measure the thickness, doping concentration, defect density, and roughness of the epitaxial film. In other words, accurately measuring the actual temperature within the process chamber involved in the embodiments of this application is relatively difficult.

[0025] To this end, the inventors, through further creative effort and a shift in approach, have presented the technical solution claimed in this application. The main technical idea is to calibrate the correspondence between process temperature and process parameters, ensuring that when any set of corresponding calibrated process temperatures and parameters is used in the process chamber for epitaxial growth, the uniformity of the process results is relatively good. Based on this, the calibration relationship is used to verify the temperature setting programs of other process chambers with the same parameters, so that, given a fixed temperature, the process chamber can achieve relatively good uniformity of the epitaxial growth results based on the called process parameters. The process parameters corresponding to different process temperatures can be referred to as temperature calibration menus, which may specifically include the amount of reaction source, etc.

[0026] It should be noted that, depending on the accuracy of the temperature data used as the standard value in the calibration process of this application, the temperature completed during the calibration process of verifying the temperature of the process chamber based on the above calibration relationship is not necessarily equal to the actual value in the process chamber. The aforementioned verified temperature itself is still a set value, which only corresponds to specific process parameters and does not have the significance of characterizing the actual temperature of the process chamber.

[0027] As mentioned above, in epitaxial processes, there is a correlation between process parameters such as the amount of reaction source and process temperature, and both affect the epitaxial process results. In order to obtain the correspondence between process parameters and process temperature, the inventors discovered that, taking silicon carbide as the material of the epitaxial layer as an example, based on the technical principle that different growth modes in epitaxial growth are only affected by temperature, the process chamber can be subjected to epitaxial processes at different temperatures by controlling variables. Then, the process results of the boundary between the two growth modes can be used to determine the correspondence between process temperature and process parameters. Of course, the aforementioned correspondence also includes the specific situation of the process results.

[0028] In other words, by performing epitaxial growth at different process temperatures, we can obtain the correspondence between process temperature, process parameters, and process results. Specifically, the process parameters refer to the amount of reaction source used, and the process results refer to the location of the boundary line between the two growth modes. Furthermore, since epitaxial growth always employs a substrate rotation process, the process temperature is the same at locations with the same radius on the substrate. Consequently, the boundary line between epitaxial films formed using different growth modes on the substrate is typically circular. Therefore, the process result can also be the radius of the boundary line between the two growth modes.

[0029] More specifically, by changing the amount of reaction source while keeping the temperature constant, the position of the boundary between growth patterns can be changed; correspondingly, by changing the temperature while keeping the amount of reaction source constant, the position of the boundary between growth patterns can also be changed.

[0030] Based on the above, this application discloses a method for temperature verification of a process chamber, comprising:

[0031] S1. Based on the set value of the process temperature in the process chamber, obtain the temperature calibration menu corresponding to the temperature range where the set value is located.

[0032] The setpoint is the temperature measured by the temperature sensing devices within the process chamber. The process chamber uses this measured value as the setpoint temperature for the process. Each time a process is performed in the process chamber, the process can be controlled by setting the corresponding process temperature. Accordingly, the process chamber can call up relevant process parameters, such as process recipes, from the calibration menu corresponding to the setpoint, ensuring the normal operation of the process. That is, each process temperature setpoint corresponds to a specific calibration menu, and there is a one-to-one correspondence between process temperatures and calibration menus. However, this does not necessarily mean that different process temperatures will have different calibration menus.

[0033] Furthermore, each process temperature corresponds to a specific temperature range, and the calibration menu for any temperature within each range is the same. However, different temperature ranges typically have different calibration menus. Of course, this is not always true; different epitaxial processes may result in different temperature ranges having the same calibration menu. Naturally, even with the same calibration menu, different temperature values ​​within the same temperature range will produce different process results, meaning the location (i.e., radius) of the boundary between the two growth modes on the epitaxial layer will differ.

[0034] Following step S1 above, the temperature verification method further includes:

[0035] S2. The process chamber is controlled to perform the process according to the temperature calibration menu to form an epitaxial layer on the surface of the transparent substrate. Specifically, in the above steps, the set value of the process temperature can be used to determine the temperature calibration menu corresponding to the set value, so that the chamber can perform the process based on the aforementioned temperature calibration menu. As mentioned above, based on the determined temperature calibration menu, the specific situation of the epitaxial layer formed is also different under different process temperatures. Therefore, in this embodiment, based on the correspondence between the radius of the boundary line and the temperature, under the determined temperature calibration menu, the value of the process temperature during the calibration process can be calibrated by determining the radius of the boundary line on the epitaxial layer. In subsequent processes, in order to obtain the required process results, the correspondence between the set value of the process temperature of the process chamber and the temperature calibration menu is accurate. It should be noted that the substrate is made of silicon carbide and has a 4H crystal structure. Therefore, the substrate is transparent, i.e., the aforementioned transparent substrate. In addition, as mentioned above, when the epitaxial layer material is silicon carbide, if the temperature is suitable, the formed epitaxial layer may be formed by two different growth modes: step flow growth mode and two-dimensional nucleation growth mode. The silicon carbide epitaxial layer formed by step flow growth mode is transparent, while the silicon carbide epitaxial layer formed by two-dimensional nucleation growth mode is opaque. This will be discussed in more detail below.

[0036] Furthermore, in the temperature verification method disclosed in the embodiments of this application, after S2 above, it further includes:

[0037] S3. If the epitaxial layer has transparent and non-transparent regions, then the temperature calibration menu is determined to be the target temperature calibration menu corresponding to the process temperature. Specifically, as described above, during the formation of a silicon carbide epitaxial layer on a silicon carbide substrate, if the temperature is suitable, the formed epitaxial layer may include portions formed by two different growth modes. Therefore, if the epitaxial layer has transparent and non-transparent regions, then obviously, the process temperature for epitaxial processing based on the temperature calibration menu corresponding to the above-mentioned set value is the "suitable temperature" mentioned above. In this case, the aforementioned temperature calibration menu is the target temperature calibration menu corresponding to the process temperature. Based on this temperature calibration menu and the specific situation of the epitaxial layer, the theoretical value of the aforementioned process temperature can be determined.

[0038] Therefore, the temperature calibration method further includes:

[0039] S4. Measure the radius of the boundary line between the transparent and non-transparent areas. Specifically, the radius of the boundary line between the transparent and non-transparent areas on the epitaxial layer can be measured using relevant measuring instruments.

[0040] Subsequently, temperature calibration methods also include:

[0041] S5. Based on the radius of the boundary line, the target temperature calibration menu, and the pre-established correspondence between temperature and radius in each of the multiple temperature ranges, determine the theoretical value of the process temperature when the process chamber is processed according to the target temperature calibration menu.

[0042] As described above, the epitaxial process includes multiple temperature ranges, and each temperature range corresponds to a calibration menu. Therefore, there is a one-to-one correspondence between multiple temperature ranges and multiple calibration menus. Simultaneously, for each temperature range, the multiple temperature values ​​it includes also correspond to a specific radius value of a boundary line. The aforementioned elements together constitute a pre-established correspondence between temperature and radius within each of the multiple temperature ranges. Based on this correspondence, when the target calibration menu is determined, the corresponding target temperature range can be determined. Furthermore, based on the specific relationship between multiple temperature standard values ​​and radius standard values ​​within the target temperature range, when the radius of the boundary line is measured and determined, the temperature standard value corresponding to the radius standard value in the target temperature range that is equal to or equivalent to the measured radius is the theoretical value of the process temperature in the process chamber when the process is performed according to the aforementioned target calibration menu.

[0043] Furthermore, the temperature calibration method also includes:

[0044] S6. Determine the compensation value corresponding to the set value based on the difference between the theoretical value and the set value.

[0045] In other words, for the process carried out in this process chamber under the above-mentioned set values, the theoretical process temperature should be the above-mentioned theoretical value. Therefore, the difference between the theoretical value and the set value can be used to determine the compensation value corresponding to the above-mentioned set value. Accordingly, the sum of the original set value and the compensation value can be used as the new set value corresponding to the above-mentioned set value to achieve the purpose of temperature verification.

[0046] Accordingly, when the process temperature range of the process chamber is expanded, the more appropriate value for each temperature value in the process temperature range should be the sum of the original set values ​​and the compensation values. Therefore, the original temperature setting program in the process chamber can be replaced based on this logic.

[0047] For example, if the original process temperature setting of the process chamber is 1600°C, and the process chamber executes a temperature calibration menu corresponding to the temperature range of 1600°C, and performs an epitaxial process to form an epitaxial layer on the surface of a transparent substrate, then if the set temperature of the process chamber is the same as the corresponding process temperature in the aforementioned temperature calibration menu, the process result should also be the same as the process result corresponding to that process temperature in the aforementioned temperature range. That is, the radius of the epitaxial layer boundary line under the actual process is the same as the radius corresponding to the set value in the aforementioned correspondence. In this case, the temperature of the process chamber does not need to be recalibrated, and therefore will not be described in detail.

[0048] Conversely, if the set temperature of the process chamber differs from the process temperature in the temperature range corresponding to the aforementioned temperature calibration menu, the process result will also differ from the radius value corresponding to the process temperature in that temperature range. Therefore, it can be determined that the actual process temperature of the process chamber needs to be recalibrated. In this case, the theoretical value of the process temperature of the process chamber can be determined by measuring the specific value of the radius of the boundary between the transparent and non-transparent areas in the process result, and based on the correspondence between the boundary radius and the temperature. Taking a theoretical value of 1612℃ as an example, the difference between the theoretical value and the aforementioned set value is 12℃. In this case, the original set value of 1600℃ should be verified to the new 1612℃. Correspondingly, each temperature value in the original process temperature setting program of the process chamber should be verified to "initial value + 12℃".

[0049] As described above, in the temperature verification method disclosed in the embodiments of this application, the temperature range typically includes multiple temperature ranges, which are sequentially adjacent and can collectively constitute the process temperature range used in the epitaxial process within the process chamber. For example, the temperature range used in the process chamber for the epitaxial process can be 1400℃~1700℃, and the multiple temperature ranges can specifically include [1400℃~T1℃], [T1℃~T2℃], [T2℃~T3℃], ..., [Tn-1℃~Tn℃] and [Tn℃~1700℃]. The specific division of each temperature range can be flexibly determined according to the actual situation, and this document does not impose any limitations on it.

[0050] As described above, when both the substrate and the epitaxial layer are made of silicon carbide, the transparent regions are formed by a step-flow growth mode, and the non-transparent regions are formed by a two-dimensional nucleation growth mode. Specifically, taking a horizontally inlet epitaxial device as an example, the temperature at the center of the substrate is typically relatively high, and the temperature gradually decreases from the center of the substrate towards its outer edge. Since the step-flow growth mode requires a relatively higher temperature than the two-dimensional nucleation growth mode, all other things being equal, given a specific flux of the reaction source, epitaxial layers can be formed simultaneously on the substrate using both growth modes. Figure 2 As shown, the transparent region 1 of the epitaxial layer is formed by a step flow growth mode, and the non-transparent region 2 of the epitaxial layer is formed by a two-dimensional nucleation growth mode.

[0051] This application discloses a method for temperature calibration of a process chamber. Based on a setpoint for the process temperature of the process chamber, after obtaining a calibration menu corresponding to the temperature range of the setpoint, the method controls the process chamber to perform the process according to the calibration menu to form an epitaxial layer on the surface of a transparent substrate. If the setpoint does not need to be corrected, the process result produced by the process based on the specific setpoint should be the same as the process result produced by the process based on the same temperature standard value. Conversely, the specific circumstances of the process result produced by the process based on the specific setpoint, combined with the correspondence between the process result and the standard temperature value, can also be used to infer whether the setpoint needs to be corrected. Specifically, the process result can be represented by the specific location of the boundary line between the transparent and non-transparent regions in the epitaxial layer, i.e., the radius of the boundary line. Therefore, if the epitaxial layer has transparent and non-transparent regions, the above temperature calibration menu can be considered as the target temperature calibration menu corresponding to the process temperature. Based on this target temperature calibration menu, the target temperature range can be determined. The theoretical value of the process temperature is located in the target temperature range, and there is a corresponding relationship between the theoretical value of the process temperature and the radius of the boundary line between the transparent and non-transparent regions.

[0052] Furthermore, by measuring the radius of the boundary between the transparent and non-transparent regions in the epitaxial layer formed by the process based on the temperature calibration menu corresponding to the set value, and based on the measured radius, the target temperature calibration menu, the target temperature range, and the correspondence between temperature and radius within the temperature range, the theoretical value of the temperature corresponding to that radius can be determined. The difference between this theoretical value and the set value can then be used to determine the compensation value corresponding to the set value. Accordingly, the sum of the set value and the compensation value is the new set value corresponding to the set value. Accordingly, for each process temperature set value within the process temperature range of the process chamber, the sum of the compensation value and each set value can be used as the new set value. To distinguish between historical set values ​​and new set values, this new set value can be denoted as the calibration value.

[0053] Based on the above technical solution, the correspondence between the temperature of the process chamber and the temperature calibration menu can be verified, thereby ensuring that when the process is carried out using the temperature calibration menu with the corresponding relationship and the set temperature, the uniformity of the process results can be relatively good.

[0054] As described above, in the temperature calibration method disclosed in the embodiments of this application, there is a specific temperature calibration menu for each temperature range, and under the aforementioned specific temperature calibration menu, there is a specific process result for each temperature value in the temperature range, and the aforementioned process result is displayed in terms of the radius of the dividing line.

[0055] Here, in the process of determining the process result corresponding to each temperature range under a specific temperature calibration menu, the radius of the boundary line in the process result corresponding to the first end value of the temperature range can be made to be the radius of the substrate, and the radius of the boundary line in the process result corresponding to the second end value of the temperature range can be 0. That is, at this time, the boundary line is located at the center of the substrate.

[0056] However, when using the above technical solution, if the epitaxial layer formed on the substrate surface is indeed formed entirely by a certain growth mode after the process is carried out based on the temperature calibration menu corresponding to the set value of the process chamber, it is impossible to determine whether the process temperature of the process chamber is exactly at the end of the temperature range where the set value is located, or whether the process temperature is much higher (or much lower) than the end of the temperature range where the set value is located.

[0057] Therefore, when using the above-mentioned design for the end values ​​and the radius of the boundary line of the temperature range, during the temperature verification process, there may be a situation where the difference between the set temperature of the process chamber being verified and the verification temperature is relatively large. As a result, the epitaxial layer formed on the surface of the substrate may be formed independently by a certain growth mode. That is, after the process based on the above S2, the epitaxial layer does not have a boundary line between the transparent and non-transparent areas.

[0058] To address this situation, taking the example that the growth temperature required for the transparent region is greater than that required for the non-transparent region, the temperature verification method disclosed in this application may further include, before measuring the radius of the boundary between the transparent and non-transparent regions:

[0059] If the epitaxial layer is formed by a transparent region, then the temperature range in which the set value is located shall be the first temperature range;

[0060] Get the second temperature calibration menu corresponding to the second temperature range that is adjacent to the first temperature range and is larger than the first temperature range;

[0061] The process chamber is controlled to perform the process according to the second temperature calibration menu to form a second epitaxial layer on the surface of the transparent substrate;

[0062] If the second epitaxial layer has transparent and non-transparent regions, then the second temperature calibration menu is determined to be the target temperature calibration menu corresponding to the process temperature.

[0063] As mentioned above, due to individual differences in process chambers, it is possible that the temperature range in which the process temperature of the chamber should be calibrated is not the same as the temperature range in which the set process temperature of the chamber is located. In this case, the aforementioned situation occurs, resulting in the epitaxial layer formed based on the temperature calibration menu corresponding to the set temperature range being entirely formed by the same growth mode (i.e., transparent or non-transparent regions). In the embodiments of this application, the epitaxial layer being formed entirely by transparent regions is taken as an example.

[0064] As described above, if the epitaxial layer is formed entirely by a step-flow growth mode, i.e., the epitaxial layer is a completely transparent structure, then obviously, there is a possibility that the temperature of the process chamber should be higher than the set value of the process chamber. In this case, the process temperature needs to be recalibrated. Since the epitaxial layer only has transparent areas, the theoretical value of the process temperature of the process chamber should be greater than the maximum value of the temperature range containing the set value. Therefore, the temperature range containing the set value can be used as the first temperature range. When selecting the second temperature range, the one of the two temperature ranges adjacent to the first temperature range whose overall range is higher than the temperature range containing the set value should be selected as the second temperature range. Of course, if the epitaxial layer is formed entirely by a two-dimensional nucleation growth mode, i.e., the epitaxial layer only has non-transparent areas, then the one of the two temperature ranges adjacent to the temperature range whose overall range is lower than the temperature range containing the set value should be selected as the temperature range to be used in the next process. For distinction, the aforementioned temperature range can be referred to as the third temperature range.

[0065] Taking the case where the epitaxial layer is formed by a transparent region as an example, in this case, by changing the temperature calibration menu to a second temperature calibration menu corresponding to the second temperature range, and having the process chamber re-process according to the second temperature calibration menu, a new epitaxial layer (denoted as the second epitaxial layer) is formed. Correspondingly, if the second epitaxial layer has transparent and non-transparent regions, the second temperature calibration menu can be determined as the target temperature calibration menu corresponding to the process temperature. Correspondingly, the target temperature range can be determined. Then, similar to the above embodiment, by measuring the radius of the boundary line, and based on the correspondence between the radius of the boundary line, the second temperature calibration menu, and the temperatures and radii in the second temperature range, the theoretical value of the process temperature corresponding to the process chamber processing with the above-mentioned set value can be determined. The compensation value between the theoretical value and the set value is used to achieve the calibration purpose of the above-mentioned set value. Of course, the temperature setting program of the process chamber also needs to be corrected as a whole. The correction method is the same as that in the above embodiment, and will not be repeated here.

[0066] However, if the temperature range in which the process temperature should be calibrated is located is not adjacent to the temperature range in which the above-mentioned set value is located, that is, there may still be one or more other temperature ranges between the two temperature ranges, then even if the process is carried out using the second temperature calibration menu corresponding to the second temperature range, the second epitaxial layer formed will still be entirely formed by transparent areas.

[0067] In view of the above situation, the temperature verification method disclosed in this application further includes:

[0068] If the epitaxial layer is still formed by transparent regions, then the current second temperature range is taken as the first temperature range, and the process returns to retrieve the second temperature calibration menu corresponding to the second temperature range that is adjacent to the first temperature range and is larger than the first temperature range, until the second epitaxial layer has both transparent and non-transparent regions.

[0069] As mentioned above, the selection of the temperature range is related to the specific growth mode of the epitaxial layer. Therefore, when both the second epitaxial layer and the epitaxial layer are formed entirely by the same growth mode, it indicates that the theoretical value of the process temperature when the process chamber performs the process using the first and second temperature calibration menus should still be greater than the maximum value of the second temperature range. Therefore, the aforementioned second temperature range can be used as a new first temperature range. In this case, a new second temperature calibration menu can be obtained that is adjacent to the new first temperature range and is greater than the first temperature range, and the process chamber can be controlled to perform the process using the new second temperature calibration menu. In this embodiment, even if the epitaxial layer formed under the new second temperature calibration menu still only has transparent areas, by continuously changing the first temperature range, the formed epitaxial layer can have both transparent and non-transparent areas. At this time, the temperature calibration menu used in the aforementioned process can be considered the target temperature calibration menu, and correspondingly, the target temperature range can also be determined.

[0070] Clearly, by sequentially selecting the calibration menus corresponding to the aforementioned multiple temperature ranges for each process, it is possible to establish a boundary between transparent and non-transparent regions in the epitaxial layer formed on the substrate surface when using a calibration menu corresponding to a specific temperature range. In this case, by measuring the radius of this boundary line and based on the correspondence between the radius and temperature, the theoretical value that the process temperature setpoint of the process chamber should be calibrated can be determined.

[0071] As described above, the substrate used in this embodiment is a 4H-type silicon carbide substrate, and the material of the formed epitaxial layer is also silicon carbide. Furthermore, the crystal form of the epitaxial layer formed by the step-flow growth mode is also 4H, the same as the original transparent substrate. Therefore, if the formed epitaxial layer only has a transparent region, it is not necessary to replace the substrate when changing the temperature calibration menu and re-performing the process. This improves temperature calibration efficiency and significantly reduces calibration costs. Accordingly, the epitaxial layer consisting only of a transparent region formed in the previous process and the original transparent substrate constitute the transparent substrate before the next process.

[0072] As mentioned above, the epitaxial layer may also consist of only non-transparent areas. In this case, the verification process needs to be repeated. Since the structure of the non-transparent epitaxial layer is different from that of the transparent substrate, in order to ensure the accuracy of the temperature verification process, a new transparent substrate needs to be replaced before the epitaxial layer is formed from non-transparent areas and before the next process is carried out.

[0073] In addition, as mentioned above, any two adjacent temperature ranges are continuous with each other and each corresponds to a specific temperature calibration menu. Therefore, during the temperature calibration process, it is possible that when the process is carried out using the first temperature calibration menu corresponding to the first temperature range where the set value is located, the epitaxial layer is formed entirely by transparent areas, and when the process is carried out using the second temperature calibration menu corresponding to the adjacent second temperature range which is larger than the first temperature range, the second epitaxial layer is formed entirely by non-transparent areas.

[0074] In light of the above, the set value of the process temperature in the process chamber can be considered as the common endpoint value of the first and second temperature ranges. That is, the common endpoint value of the first and second temperature ranges is the theoretical value of the process temperature in the process chamber. Specifically, in this embodiment, the process result changes continuously during the division of temperature ranges. Since the overall range of the second temperature range is higher than the overall temperature range of the first temperature range, when the calibrated temperature is the right endpoint value of the first temperature range (i.e., the left endpoint value of the second temperature range), when performing the process based on the first temperature calibration menu corresponding to the first temperature range, the boundary line of the epitaxial layer can be located at the edge of the substrate (i.e., the epitaxial layer is entirely formed by transparent areas). Therefore, when performing the process based on the second temperature calibration menu corresponding to the second temperature range, even if the calibrated temperature is still the right endpoint value of the temperature range (i.e., the left endpoint value of the second temperature range), the new boundary line of the epitaxial layer in the resulting process result can be located at the center of the substrate (i.e., the epitaxial layer is entirely formed by non-transparent areas).

[0075] Therefore, the temperature verification method disclosed in the embodiments of this application further includes:

[0076] If the epitaxial layer is formed by a transparent region and the second epitaxial layer is formed by a non-transparent region, the common endpoint value of the first temperature range and the second temperature range is determined to be the theoretical value of the process temperature of the process chamber.

[0077] The above embodiments describe a case where the epitaxial layer formed by the process chamber based on a first temperature calibration menu corresponding to a set value consists only of transparent areas. As mentioned above, it is also possible that the epitaxial layer formed by the process chamber based on a first temperature calibration menu corresponding to a set value consists only of non-transparent areas. Therefore, the temperature calibration method disclosed in this application further includes, before measuring the radius of the boundary between the transparent and non-transparent areas:

[0078] If the epitaxial layer is formed from a non-transparent region, then the temperature range in which the set value is located shall be the first temperature range;

[0079] Get the third temperature calibration menu corresponding to the third temperature range that is adjacent to the first temperature range and smaller than the first temperature range;

[0080] The process chamber is controlled to perform the process according to the third temperature calibration menu to form a third epitaxial layer on the surface of the transparent substrate;

[0081] If the third epitaxial layer has transparent and non-transparent areas, then the third temperature calibration menu is determined to be the target temperature calibration menu corresponding to the process temperature;

[0082] If the third epitaxial layer is still formed by non-transparent regions, then the current third temperature range is taken as the first temperature range, and the process returns to retrieve the third temperature calibration menu corresponding to the third temperature range that is adjacent to the first temperature range and smaller than the first temperature range, until the third epitaxial layer has both transparent and non-transparent regions.

[0083] Correspondingly, even after changing to a new temperature calibration menu, it is still possible to obtain process results that are completely opposite to those of the previous process. Therefore, the temperature calibration method also includes:

[0084] When the third epitaxial layer is formed by a transparent region, the common endpoint value of the temperature range and the third temperature range is determined to be the theoretical value of the process temperature of the process chamber.

[0085] Considering that the main logic of this embodiment corresponds to the above embodiments, and further, for the sake of brevity, this embodiment will not be described in detail here. Those skilled in the art can understand the embodiments of this application based on the above embodiment in which the epitaxial layer is formed only by transparent areas.

[0086] It should be noted that when the growth temperature required for the transparent region is lower than that required for the non-transparent region, if the epitaxial layer is formed from the transparent region, the specific implementation method can refer to the case where the epitaxial layer is formed from the non-transparent region described above; if the epitaxial layer is formed from the non-transparent region, the specific implementation method can refer to the case where the epitaxial layer is formed from the transparent region described above; further details will not be elaborated here.

[0087] As described above, the pre-established correspondence between temperature and radius in each of the multiple temperature ranges includes a one-to-one correspondence between multiple standard temperature values ​​and multiple standard radius values. Therefore, step S5 above may include:

[0088] Based on the target temperature calibration menu, determine the target temperature range, and the multiple radius standard values ​​corresponding to the multiple temperature standard values ​​in the target temperature range;

[0089] Based on the radius of the dividing line, determine the temperature standard value corresponding to the radius standard value that is equal to the radius among multiple radius standard values. This value represents the theoretical process temperature of the process chamber when the process is performed according to the target temperature calibration menu.

[0090] As mentioned above, each temperature range corresponds one-to-one with a temperature calibration menu. Therefore, given a target temperature calibration menu, the target temperature range can be determined accordingly. The target temperature range includes multiple temperature standard values, and correspondingly, each temperature standard value corresponds to a radius standard value. In this case, based on the radius of the boundary between the transparent and non-transparent regions of the epitaxial layer obtained through direct measurement, the target temperature can be considered to be the one among the multiple temperature standard values ​​in the target temperature range that is equal to the aforementioned measured radius. That is, the aforementioned temperature standard value is the theoretical value of the process temperature when the process chamber performs the process according to the target temperature calibration menu.

[0091] More specifically, this section further explains the correspondence between the radius and temperature mentioned above, as well as the division of temperature ranges.

[0092] Based on the type of the process chamber to be verified (denoted as the verification chamber), the same epitaxial process is performed in a process chamber of the same type (denoted as the test chamber) to form an epitaxial layer on the surface of the substrate. During this process, a specific temperature is used as the set process temperature for the test chamber. For example, if the process temperature range of this type of process chamber is 1400℃~1700℃, then 1400℃ can be used as the initial set process temperature.

[0093] With the process temperature set at 1400℃, an epitaxial process is performed based on the original temperature calibration menu of the process chamber (i.e., the amount of reaction source introduced), and an epitaxial layer is formed on the substrate. The presence of a boundary between transparent and opaque regions on this epitaxial layer is then observed. If there is no boundary between the two growth modes on the epitaxial layer formed in the aforementioned process, the amount of reaction source can be increased or decreased based on the specific growth mode of the formed epitaxial layer until, at the set process temperature of 1400℃, the epitaxial layer formed on the substrate exhibits a boundary between the two growth modes. For ease of description, the example is still assumed to include both step flow growth mode and two-dimensional nucleation growth mode, and the process chamber is a horizontally inlet epitaxial device.

[0094] Subsequently, by repeatedly and continuously increasing the amount of reaction source, the boundary line can be gradually moved to the center of the formed epitaxial layer. Of course, as described in the above embodiments, in order to facilitate temperature calibration, the radius of the boundary line corresponding to the end value of the temperature range can be greater than 0. Therefore, in this embodiment, the amount of reaction source can be increased to move the boundary line to a position with a radius of 5 mm. At this time, the amount of reaction source is recorded and denoted as temperature calibration menu 1.

[0095] Subsequently, the flow rate of the reaction source into the test chamber is adjusted using the aforementioned temperature calibration menu 1. By repeatedly and continuously increasing the set process temperature, the boundary line can be gradually moved to the edge of the substrate without changing the flow rate of the reaction source. As mentioned above, to reduce the difficulty of temperature calibration, the radius of the boundary line corresponding to the end value of the temperature range can be smaller than the radius of the substrate. Therefore, in this embodiment, the radius is 70 mm. During this process, the specific value of the set process temperature when the boundary line is at 70 mm, with the amount of reaction source corresponding to temperature calibration menu 1, can be obtained and denoted as T1. The aforementioned specific value and the aforementioned 1400°C constitute a temperature range, namely [1400°C, T1]. The temperature calibration menu (i.e., the flow rate of the reaction source) corresponding to this temperature range is denoted as the flow rate corresponding to the aforementioned temperature calibration menu 1.

[0096] Simultaneously, during the above process, multiple sets of correspondences between the set process temperatures and the radii of the boundary lines can be obtained. The number of these correspondences is related to the difference between the set process temperatures. In a specific embodiment of this application, during the process of establishing the correspondence between the set process temperatures and the boundary lines, the difference between any two adjacent set process temperatures can be made equal. This improves the accuracy of the correspondence, and the functional relationship between the temperature and the radius of the boundary lines can be obtained using the aforementioned correspondences. Furthermore, for the radius value of a boundary line that does not appear, the temperature corresponding to that radius value can be obtained through methods such as interpolation algorithms. Further, the difference between any adjacent temperatures can be made equal to the temperature control accuracy of the process chamber. In a specific embodiment of this application, the temperature control accuracy can be 2℃.

[0097] Then, by increasing the amount of reaction source introduced, the radius of the boundary line of the epitaxial layer formed on the substrate when the process temperature is set to T1 can be moved back to a position with a radius of 5mm. The amount of reaction source introduced under this condition is recorded and recorded as temperature calibration menu 2.

[0098] Next, the flow rate of the reaction source into the test chamber is adjusted using the aforementioned temperature calibration menu 2. The set process temperature is then continuously increased multiple times. During this process, the temperature increase can be adjusted to achieve the aforementioned temperature control precision. In this case, without changing the flow rate of the reaction source, the boundary line can be gradually moved back to the edge region of the substrate by changing the set process temperature, for example, moving the boundary line to a position with a radius of 70 mm. During this process, the specific value of the set process temperature when the boundary line is at 70 mm, using the amount of reaction source corresponding to temperature calibration menu 2, can be obtained and denoted as T2. This specific value, along with T1, constitutes the next temperature range, [T1, T2]. The temperature calibration menu (i.e., the flow rate of the reaction source) corresponding to this temperature range is denoted as the flow rate corresponding to temperature calibration menu 2. Simultaneously, during this process, multiple sets of correspondences between the set process temperature and the radius of the boundary line can also be obtained.

[0099] Subsequently, by further increasing the flow rate of the reaction source, the radius of the boundary line on the formed epitaxial layer can be moved back to 5 mm when the process temperature is set to T2. The process temperature is then gradually increased multiple times to move the radius of the boundary line on the epitaxial layer to 70 mm. The flow rate of the reaction source used at this time is recorded as temperature calibration menu 3. The process temperature when the boundary line is at 70 mm during this process is obtained and recorded as T3. Correspondingly, the correspondence between each set process temperature and the radius of the boundary line in the temperature range [T2, T3] can also be obtained.

[0100] By analogy, the standard value of the radius of the boundary line corresponding to any temperature in the process temperature range of the test chamber can be obtained. At the same time, the multiple temperature intervals into which the above process temperature range is divided can also be obtained, as well as the temperature calibration menu corresponding to each temperature interval, i.e. the amount of reaction source introduced. This forms a correspondence between the amount of reaction source introduced, the calibrated process temperature, and the radius of the boundary line, which is the correspondence between radius and temperature mentioned in the above embodiment.

[0101] Based on the above correspondence, during the temperature calibration of the calibration chamber, the radius of the boundary line formed on the epitaxial layer can be used to determine the value of the temperature that should be calibrated, and the temperature setting program of the calibration chamber can be corrected using this value, so that the process uniformity of the calibration chamber is relatively good in subsequent processes.

[0102] Since each temperature range contains an infinite number of natural numbers, it is impossible to obtain the standard value of the radius of the boundary line corresponding to each natural temperature number during the establishment of the above correspondence. Therefore, in the actual verification process, after performing the process based on the temperature calibration menu corresponding to the temperature range where the process temperature setting of the verification chamber is located, it is possible that the measured value of the radius of the boundary line of the formed epitaxial layer does not appear in the standard values ​​of multiple radii in the correspondence between radius and temperature.

[0103] Based on the above problems, as mentioned above, in the actual inspection process, the theoretical value of the temperature corresponding to the measured value of a certain radius can be determined by means such as interpolation algorithms, and this theoretical value can be used as the above-mentioned theoretical value of the process temperature.

[0104] In another embodiment of this application, in order to minimize the difficulty of temperature calibration, one of the temperatures corresponding to two standard values ​​adjacent to the measured value of the radius of the boundary line can be used as the theoretical value of the process temperature of the test chamber. More specifically, the temperature corresponding to the one with the smaller absolute value of the difference between the two measured values ​​adjacent to the measured value can be used as the theoretical value of the test chamber. For example, when using the above-mentioned temperature calibration menu 1 for the process, the radius of the dividing line is 14mm when the process temperature is set to 1402℃, and 22mm when the process temperature is set to 1404℃. At this time, if the setting value of the calibration chamber is in the temperature range of [1400℃, T1], and the temperature calibration work of the calibration chamber is performed with the process temperature set to 1400℃ and the process is performed using the temperature calibration menu corresponding to the above-mentioned temperature calibration menu 1, the radius of the dividing line on the epitaxial layer formed is measured to be 20mm. In this case, since the difference between the measured value of the dividing line radius and the standard value of the dividing line radius corresponding to 1402℃ is relatively small, the temperature value corresponding to the standard value of the radius of 22mm, i.e., 1402℃, should be used as the theoretical value of the process temperature of the test chamber. Therefore, the temperature setting value of the test chamber needs to be corrected from 1400℃ to 1402℃, and the temperature setting program of the test chamber needs to be adaptively corrected.

[0105] Therefore, in this embodiment of the application, step S5 may further include:

[0106] When multiple standard radius values ​​in the target correspondence are not equal to the radius, determine the two standard radius values ​​adjacent to the radius.

[0107] Obtain the difference between each of the two standard radius values ​​and the radius itself;

[0108] The standard value of the radius corresponding to the smaller of the two absolute values ​​is determined to be the theoretical value of the process temperature of the process chamber when the process is carried out according to the target temperature calibration menu.

[0109] In step S5 of this application embodiment, when the above embodiment is adopted, there may be a situation where the absolute value of the difference between the measured value of the radius and the standard value of the two radii adjacent to the measured value is equal. In this case, the theoretical value of the process temperature of the calibration chamber is not accurate when the temperature corresponding to the standard value of the two radii is used as the theoretical value of the process temperature of the calibration chamber. Therefore, in this case, the average value of the temperature corresponding to the standard value of the two radii can be used as the theoretical value of the process temperature of the calibration chamber.

[0110] Based on the above, in the temperature verification method disclosed in this application, step S5 may further include:

[0111] When the absolute values ​​of the two differences are equal, the average value of the temperature standard values ​​corresponding to the two radius standard values ​​is determined as the theoretical value of the process temperature of the process chamber when the process is carried out according to the target temperature calibration menu.

[0112] As mentioned above, when the specific value of the radius of the boundary between the transparent and non-transparent regions in the epitaxial layer formed under actual processes is not included in the standard radius value corresponding to the relevant temperature range, an approximate approach can be used to determine the standard temperature value corresponding to the measured value of the aforementioned radius. In the aforementioned technical solution, if the difference between any two adjacent standard temperature values ​​in the temperature range (such as the aforementioned difference being 2℃) is relatively small, the above technical solution is relatively simple, and the determined standard temperature value will not have a relatively large error.

[0113] However, if the difference between any two adjacent temperature standard values ​​within the temperature range is relatively large, such as greater than 5°C, then using the above technical solution may result in a relatively large difference between the determined temperature standard value and the actual value. Therefore, in order to further improve the consistency of the epitaxial process, in another embodiment of this application, the verification method may further include:

[0114] When multiple radius standard values ​​in the target correspondence are not equal to the radius, the ratio of the difference between the radius and the first radius standard value corresponding to the first end value of the temperature range is determined in the difference between the second radius standard value corresponding to the second end value of the temperature range and the first radius standard value. The theoretical value of the process temperature of the process chamber when performing the process according to the target temperature calibration menu is the sum of the product of the difference between the second end value and the first end value of the temperature range and the ratio.

[0115] That is, in this embodiment of the application, the temperature standard value is determined by a ratio, which can further improve the accuracy of the temperature standard value determination. The first end value of the temperature range can be its relatively smaller end value. If the temperature range is [T1, T2], and the difference between temperatures T1 and T2 is ΔT, then the first radius standard value corresponding to T1 can be R1, and the second radius standard value corresponding to T2 can be R2. Based on this, the aforementioned ratio coefficient is (r-R1) / (R2–R1). Correspondingly, if the measured radius value is r, then the temperature standard value corresponding to this radius value can specifically be (r-R1) / (R2–R1)*(T2–T1)+T1.

[0116] As mentioned above, in the process of dividing the temperature range and determining the temperature calibration menu, by adjusting the corresponding data, the epitaxial layer formed when the process chamber is processed with the first and second end values ​​of each temperature range can be formed independently by transparent or non-transparent regions.

[0117] However, if the epitaxial layer is formed independently by transparent or non-transparent regions when the above technical solution is adopted, a large number of repeated verification processes are required, which makes temperature verification more difficult.

[0118] Furthermore, to reduce the difficulty of subsequent temperature verification of the process chamber, in another embodiment of this application, the boundary line corresponding to the first end value of any temperature range in the pre-established temperature calibration menus and the correspondence between temperature and radius can be located inside the outer edge of the transparent substrate, and the boundary line corresponding to the second end value of any temperature range can be located outside the center of the transparent substrate. Of course, the radius of the boundary line corresponding to the first end value should be larger than the radius of the boundary line corresponding to the second end value. More specifically, the radius of the boundary line corresponding to the second end value can be greater than 1 mm to further reduce the difficulty of temperature verification and improve the accuracy of temperature verification.

[0119] In other words, in this embodiment, when using the endpoint value of any temperature range as the theoretical value of the process temperature, it can be guaranteed that the formed epitaxial layer has both transparent and non-transparent regions. In this case, the number of test results where the epitaxial layer is formed solely by transparent or non-transparent regions can be significantly reduced, thereby greatly reducing the verification difficulty and improving the verification accuracy to a certain extent. Of course, when using this embodiment, it is possible that the radius of the boundary line on the epitaxial layer is not recorded in the radius standard value corresponding to each temperature standard value in the corresponding temperature range. In this case, a second temperature range can be determined based on the actual value of the boundary line radius and the maximum or minimum value of the radius standard value corresponding to the corresponding temperature range, and the temperature verification work can be performed again.

[0120] In addition, when the above technical solution is adopted, the process is performed based on the temperature calibration menu corresponding to the temperature range where the set value is located, and an epitaxial layer is formed on the surface of the substrate. If the radius of the boundary line of the epitaxial layer is equal to the radius of the boundary line corresponding to the end value of the temperature range (the first end value or the second end value), it can be directly determined that the set value of the process temperature of the process chamber can be calibrated to the aforementioned end value. This can significantly reduce the workload in the temperature calibration process.

[0121] As described above, based on the correspondence between radius and temperature, the theoretical value of the process temperature in the chamber can be determined. Based on this theoretical value, the setpoint of the process temperature in the process chamber can be verified, forming a new setpoint, i.e., a calibration value, corresponding to this setpoint. To ensure the accuracy of the temperature verification results, in this embodiment, the temperature verification method may further include:

[0122] Verify whether the difference between the radius of the boundary line corresponding to the calibration value and the standard value of the radius corresponding to the calibration value in the corresponding relationship meets the preset difference range.

[0123] In detail, the verification process described above is essentially the same as steps S1 to S5 of this application, except that in this step, the actual process temperature used in the process chamber is the set value corrected in the above process, i.e., the calibration value. In this case, the process chamber is controlled to execute the temperature calibration menu corresponding to the temperature range of the calibration value, and an epitaxial layer is formed on the surface of the substrate. Then, by measuring the radius of the boundary line in the epitaxial layer, the measured value is compared with the standard value of the radius corresponding to the same temperature in the radius-temperature correspondence relationship between the measured value and the calibration value. If the difference between the two meets a preset difference range, the result of the temperature verification process is considered relatively accurate. Conversely, if the difference does not meet the preset difference range, a new temperature calibration value can be determined based on the measured radius of the boundary line of the epitaxial layer formed by the process performed with the calibration value, and the new calibration value is used to overwrite the original calibration value.

[0124] Of course, after the above process, the accuracy of the new calibration value can be verified again. The verification process is similar to the above process, and for the sake of brevity, it will not be repeated here.

[0125] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0126] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A method for temperature verification of a process chamber, characterized in that, The temperature verification method includes: Based on the set value of the process temperature of the process chamber, obtain the temperature calibration menu corresponding to the temperature range in which the set value is located; The process chamber is controlled to perform the process according to the temperature calibration menu to form an epitaxial layer on the surface of a transparent substrate; If the epitaxial layer has transparent and non-transparent regions, then the temperature calibration menu is determined to be the target temperature calibration menu corresponding to the process temperature; Measure the radius of the boundary line between the transparent area and the non-transparent area; Based on the radius of the dividing line, the target temperature calibration menu, and the pre-established correspondence between temperature and radius in each of the multiple temperature ranges, the theoretical value of the process temperature is determined when the process chamber performs the process according to the target temperature calibration menu. Based on the difference between the theoretical value and the set value, the compensation value corresponding to the set value is determined.

2. The temperature calibration method according to claim 1, characterized in that, Before measuring the radius of the boundary line between the transparent region and the non-transparent region, the method further includes: If the epitaxial layer is formed of a transparent region, then the temperature range in which the set value is located is taken as the first temperature range; Obtain the second temperature calibration menu corresponding to the second temperature range that is adjacent to the first temperature range and is larger than the first temperature range; The process chamber is controlled to perform the process according to the second temperature calibration menu to form a second epitaxial layer on the surface of the transparent substrate; If the second epitaxial layer has transparent and non-transparent regions, then the second temperature calibration menu is determined to be the target temperature calibration menu corresponding to the process temperature; If the epitaxial layer is still formed by transparent regions, then the current second temperature range is taken as the first temperature range, and the process returns to execute the second temperature calibration menu corresponding to the second temperature range that is adjacent to the first temperature range and is greater than the first temperature range, until the second epitaxial layer has both transparent and non-transparent regions.

3. The temperature calibration method according to claim 2, characterized in that, The temperature verification method further includes: When the second epitaxial layer is formed by a non-transparent region, the common endpoint value of the first temperature range and the second temperature range is determined to be the theoretical value of the process temperature of the process chamber.

4. The temperature calibration method according to claim 1, characterized in that, Before measuring the radius of the boundary line between the transparent region and the non-transparent region, the method further includes: If the epitaxial layer is formed from a non-transparent region, then the temperature range in which the set value is located is the first temperature range; Obtain the third temperature calibration menu corresponding to the third temperature range that is adjacent to the first temperature range and smaller than the first temperature range; The process chamber is controlled to perform the process according to the third temperature calibration menu to form a third epitaxial layer on the surface of the transparent substrate; If the third epitaxial layer has transparent and non-transparent regions, then the third temperature calibration menu is determined to be the target temperature calibration menu corresponding to the process temperature; If the third epitaxial layer is still formed by non-transparent regions, then the current third temperature range is taken as the first temperature range, and the process returns to retrieve the third temperature range corresponding to the third temperature range that is adjacent to the first temperature range and smaller than the first temperature range, until the third epitaxial layer has both transparent and non-transparent regions.

5. The temperature calibration method according to claim 4, characterized in that, The temperature verification method further includes: When the third epitaxial layer is formed by a transparent region, the common endpoint value of the temperature range and the third temperature range is determined to be the theoretical value of the process temperature of the process chamber.

6. The temperature calibration method according to claim 1, characterized in that, Based on the radius of the boundary line, the target temperature calibration menu, and the pre-established correspondence between temperature and radius in multiple temperature calibration menus, the theoretical value of the process temperature is determined when the process chamber performs the process according to the target temperature calibration menu, including: Based on the target temperature calibration menu, determine the target temperature range, and the multiple radius standard values ​​corresponding to the multiple temperature standard values ​​in the target temperature range; Based on the radius of the boundary line, the temperature standard value corresponding to the radius standard value that is equal to the radius among multiple radius standard values ​​is determined as the theoretical value of the process temperature of the process chamber when the process is performed according to the target temperature calibration menu.

7. The temperature calibration method according to claim 6, characterized in that, Also includes: When multiple radius standard values ​​in the target correspondence are not equal to the radius, determine the two radius standard values ​​adjacent to the radius. Obtain the difference between each of the two standard radius values ​​and the radius; The temperature standard value corresponding to the smaller of the absolute values ​​of the two differences is determined to be the theoretical value of the process temperature of the process chamber when the process is performed according to the target temperature calibration menu. If the absolute values ​​of the two differences are equal, the average value of the temperature standard values ​​corresponding to the two radius standard values ​​is determined as the theoretical value of the process temperature of the process chamber when the process is performed according to the target temperature calibration menu.

8. The temperature calibration method according to claim 6, characterized in that, Also includes: When multiple radius standard values ​​in the target correspondence are not equal to the radius, determine the proportionality coefficient between the difference between the radius and the first radius standard value corresponding to the first end value of the temperature range and the difference between the second radius standard value corresponding to the second end value of the temperature range and the first radius standard value; The theoretical value of the process temperature in the process chamber when the process is performed according to the target temperature calibration menu is equal to the product of the difference between the second end value and the first end value of the temperature range and the proportional coefficient, plus the first end value.

9. The temperature calibration method according to claim 1, characterized in that, In the pre-established multiple temperature calibration menus, the boundary line corresponding to the first end value of any temperature range is located inside the outer edge of the transparent substrate, and the boundary line corresponding to the second end value is located outside the center of the transparent substrate. Furthermore, the radius of the boundary line corresponding to the first end value is greater than the radius of the boundary line corresponding to the second end value.

10. The temperature calibration method according to claim 1, characterized in that, In the pre-established multiple temperature calibration menus, the temperature-radius correspondence between any two adjacent temperatures is equal, and the difference is equal to the temperature control accuracy of the process chamber.

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