Semiconductor thermal processing apparatus and temperature self-calibration method

Abstract

The application discloses a semiconductor heat treatment equipment and a temperature self-calibration method thereof. The equipment comprises a furnace body, a process tube arranged in the furnace body, and a wafer boat arranged in the process tube. The wafer boat is provided with a plurality of wafer placing areas along the axial direction of the process tube, and each wafer placing area can place a plurality of wafers to be processed. An internal temperature measuring element is arranged at the inner edge of the process tube along the axial direction of the process tube. A plurality of temperature measuring points are distributed at intervals from one end to the other end of the internal temperature measuring element, and each temperature measuring point corresponds to a wafer placing area. Each wafer placing area is used for placing a temperature measuring wafer and a wafer to be processed, and the temperature measuring wafer is provided with a wafer temperature measuring element. A control unit is connected with the internal temperature measuring element and the wafer temperature measuring element, respectively. The control unit is used for calibrating the temperature of the corresponding temperature measuring point on the internal temperature measuring element according to the temperature of the wafer temperature measuring element, so that the temperature of the temperature measuring wafer is equal to the set temperature. The application can realize the accurate automatic calibration of the temperature regulation and control of the semiconductor heat treatment equipment.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor manufacturing equipment, and more particularly, relates to semiconductor heat treatment equipment and a temperature self-calibration method thereof. Background Art

[0002] In semiconductor manufacturing fields like integrated circuits and photovoltaics, vertical or horizontal furnaces are widely used to heat-treat wafers. With the development of this industry, the requirements for temperature control accuracy are becoming increasingly stringent. During the initial installation phase, these devices require temperature calibration to ensure that the wafer temperature at the center of the furnace is approximately equal to the set temperature.

[0003] The commonly used method currently involves inserting a thermocouple closer to the wafer in the center of the furnace, using it as a proxy for the wafer temperature to calibrate the temperature-control thermocouple. However, this thermocouple is still some distance from the wafer and cannot completely reflect the wafer temperature. Furthermore, the current calibration method requires a calibrator to calculate and enter an offset value based on the thermocouple temperature, requiring repeated manual corrections until the calibration requirements are met. Summary of the Invention

[0004] The purpose of the present invention is to provide a semiconductor heat treatment device and a temperature self-calibration method thereof, so as to realize accurate automatic calibration of the temperature control of the furnace tube device.

[0005] To achieve the above objectives, the present invention provides a semiconductor heat treatment device, comprising:

[0006] A furnace body, a process tube disposed in the furnace body, and a wafer boat disposed in the process tube, wherein the wafer boat is provided with a plurality of wafer placement areas along the axial direction of the process tube, and each of the wafer placement areas can place a plurality of wafers to be processed;

[0007] An internal temperature measuring element is arranged at the inner edge of the process tube along the axial direction of the process tube, and a plurality of temperature measuring points are spaced apart from one end to the other end of the internal temperature measuring element, each of the temperature measuring points corresponds to one of the wafer placement areas, and each of the wafer placement areas is used to place a temperature measuring wafer and a wafer to be processed, and a wafer temperature measuring element is provided on the temperature measuring wafer;

[0008] A control unit, wherein the internal temperature measuring element and the wafer temperature measuring element are respectively connected to the control unit, and the control unit is used to calibrate the temperature of the corresponding temperature measuring point on the internal temperature measuring element according to the temperature of the wafer temperature measuring element so that the temperature of the temperature measuring wafer is equal to the set temperature.

[0009] Optionally, a plurality of external temperature measuring elements are provided, and the plurality of external temperature measuring elements are arranged at intervals on the outer wall of the furnace body, and each of the external temperature measuring elements is located opposite to one of the temperature measuring points on the internal temperature measuring element, and the external temperature measuring elements are connected to the control unit.

[0010] The control unit is further configured to calibrate the temperature of the corresponding external temperature measuring element according to the temperature of the calibrated internal temperature measuring element.

[0011] Optionally, the wafer temperature measuring element is welded to the temperature measuring wafer.

[0012] Optionally, the temperature measuring wafer is located at the middle position of the corresponding wafer placement area and opposite to one of the temperature measuring points on the internal temperature measuring element.

[0013] The present application further provides a temperature self-calibration method applied to the semiconductor thermal processing equipment, and the method comprises the following steps of:

[0014] Step S1: obtaining the temperature of the temperature measuring wafer in the current period by the wafer temperature measuring element, calculating the temperature compensation value of one of the temperature measuring points on the internal temperature measuring element opposite to the temperature measuring wafer based on the temperature of the temperature measuring wafer and the set temperature required by the process, and calibrating the temperature of the temperature measuring point based on the temperature compensation value;

[0015] Step S2: determining whether the temperature of the temperature measuring wafer in the current period is stable, if yes, executing step S3, otherwise, making the temperature of the temperature measuring wafer stable by temperature control, and executing step S3;

[0016] Step S3: determining whether the first difference value between the set temperature and the temperature of the temperature measuring wafer is within the preset difference value range, if yes, completing the temperature calibration of the temperature measuring point, otherwise, taking the next period as the current period, and returning to execute the step S1 to continue calibrating the temperature of the temperature measuring point.

[0017] Optionally, after executing the step S3 and completing the temperature calibration of the internal temperature measuring element, the method further comprises the following steps of:

[0018] Step S4: calculating the second difference value between the temperature of the temperature measuring point and the temperature of one of the external temperature measuring elements opposite to the temperature measuring point, and calibrating the temperature of the external temperature measuring element based on the second difference value.

[0019] Optionally, in the step S1, the temperature compensation value of the temperature measuring point is calculated by the following formula:

[0020] Offset(t) = Offset(t-1) - P × (Set - TCWafer(t-1))

[0021] Among them, Offset(t) is the temperature compensation value of the internal temperature measuring component in period t, Offset(t-1) is the temperature compensation value of the temperature measuring point on the internal temperature measuring component in period t-1, Set is the set temperature required by the process, TCWafer(t-1) is the temperature of the temperature measuring wafer obtained in period t-1, and P is the influence factor between the temperature of the temperature measuring wafer and the internal temperature measuring component.

[0022] Optionally, in step S1, the temperature of the temperature measuring point is calibrated using the following formula:

[0023] Inner(t) * =Inner(t)+Offset(t)

[0024] Among them, Inner(t) * is the temperature value of the temperature measuring point in the t period after calibration, Inner(t) is the temperature value of the temperature measuring point in the t period, Offset(t) is the temperature compensation value of the temperature measuring point in the t period, Offset(0) is the temperature compensation value of the starting period, and Offset(0)=0.

[0025] Optionally, in step S4, the temperature of the external temperature measuring component is calibrated using the following formula:

[0026] Outer(t) * =Outer(t)+Profile+Offset(t)

[0027] Among them, Outer(t) * is the temperature value of the external temperature measuring element after calibration in period t, Profile is the temperature difference between the calibrated temperature measuring point and the corresponding external temperature measuring element, and Offset(t) is the temperature compensation value of the temperature measuring point in period t.

[0028] Optionally, determining whether the temperature of the temperature-measuring wafer is stable in the current cycle includes:

[0029] The temperature variation range of the temperature measuring wafer in the current cycle is collected by the wafer temperature measuring component. If the temperature variation range is smaller than the set temperature variation range, it is determined that the temperature of the temperature measuring wafer is stable.

[0030] The beneficial effects of the present invention are:

[0031] The application sets the temperature measuring wafer which can participate in the process with the wafer to be processed on the boat, sets the wafer temperature measuring part on the temperature measuring wafer, and obtains the temperature of the temperature measuring wafer through the wafer temperature measuring part during the process, which is equivalent to obtaining the temperature of the wafer to be processed in the wafer placement area where the temperature measuring wafer is located, and the temperature of the temperature measuring wafer is equal to the set temperature. After the internal temperature measuring part corresponding to each temperature measuring point in different wafer placement areas is calibrated based on multiple temperature measuring wafers, the temperature of each temperature measuring point is equal to the set temperature. Since the internal temperature measuring part is arranged along the axial direction of the process pipe and the temperature measuring points are distributed on the internal temperature measuring part at intervals, the temperature calibration of the heat treatment equipment in the axial direction can be realized, thereby realizing the accurate and automatic calibration of the wafer temperature in the chamber, effectively improving the automation degree and reducing the labor cost.

[0032] The system of the application has other characteristics and advantages that will be apparent from or explained in the drawings and subsequent detailed description incorporated herewith, which together serve to explain certain principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0033] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures, and in which:

[0034] Figure 1 A schematic diagram of a semiconductor heat treatment equipment of the prior art is shown.

[0035] Figure 2 A schematic diagram of a semiconductor heat treatment equipment according to an embodiment of the present application is shown.

[0036] Figure 3 A step flow chart of a temperature automatic calibration method according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0037] The temperature calibration scheme of the furnace pipe of the prior art is shown as Figure 1As shown, a quartz tube 101 is placed inside the furnace body 100, and wafers 105 are placed on a wafer boat 102. A thermocouple 103 is a temperature-controlled thermocouple inside the chamber, with multiple temperature measurement points 106 located at the top, middle, and bottom of the thermocouple. A calibration thermocouple 104 is a dedicated calibration thermocouple introduced through a reserved hole in the furnace door 107 during temperature calibration. It is identical in size to the temperature-controlled thermocouple 103 and is installed at the same height as the temperature-controlled thermocouple 103. Both the temperature-controlled thermocouple 103 and the calibration thermocouple 104 are rod-shaped, with multiple temperature measurement points spaced apart on the rods. When implementing the current temperature calibration scheme, the calibration thermocouple 104 is first inserted through the reserved hole in the furnace door 107 into the chamber where the wafers 105 are located. After the temperature control is stabilized using the calibration thermocouple 104, the program automatically calculates the temperature difference measured between the internal thermocouple 103 and the external thermocouple 108, which is used to compensate for the external thermocouple 108. This allows the thermocouple 108 to continue controlling the temperature if the thermocouple 103 fails (equivalent to horizontal calibration). To ensure consistent temperatures across the wafers on the top, middle, and bottom of the wafer boat 102 (generally within ±1°C), the temperature needs to be calibrated again. After the temperature is stabilized using thermocouple 103, the calibration thermocouple 104 is slowly moved from top to bottom, recording the temperature data measured at different locations at the top temperature measurement point of the calibration thermocouple 104 (the top temperature measurement point covers the maximum measurement distance, equivalent to vertical calibration). If a temperature range falls outside the specification (for example, ±1°C), a compensation value is calculated and applied to that section of the thermocouple 103. This compensation value requires repeated adjustments by the temperature calibrator to ensure that the calibration thermocouple 104 meets the specification requirements from top to bottom.

[0038] The calculation formula and compensation formula of existing temperature calibration technology are as follows.

[0039] Profile=Inner-Outer

[0040] Outer * =Outer+Profile+Offset

[0041] Inner * =Inner+Offset

[0042] Where, Inner is the temperature value measured by the internal thermocouple 103, Inner * is the internal temperature after compensation, Outer is the temperature value measured by the external thermocouple 108, and Outer * is the compensated external temperature, Profile is the temperature difference between the internal and external thermocouples, and Offset is the compensation value calculated by the calibrator.

[0043] Existing temperature calibration technology is divided into two parts:

[0044] The first part is to achieve equivalent temperature control of the external thermocouple and the internal thermocouple. In case the internal thermocouple 103 fails, the external thermocouple 108 can be used for equivalent temperature control. The temperature difference (profile) between the internal thermocouple 103 and the external thermocouple 108 needs to be calculated during wafer thermocouple temperature control to compensate for the external thermocouple 108.

[0045] The second part is to achieve consistent temperatures at the top, middle, and bottom of the chamber by compensating the internal thermocouples in each area. The compensation value Offset is manually calculated and repeatedly corrected based on the temperature measured during the downward movement of the calibrated thermocouple during internal thermocouple temperature control.

[0046] This prior art has the following defects:

[0047] 1. It is necessary to first calculate the difference between the internal thermocouple 103 and the external thermocouple 108 to compensate for the external thermocouple 108. Then, the calibration personnel are required to manually calibrate the upper, middle and lower temperatures of the chamber multiple times, which is time-consuming and has a low degree of automation.

[0048] 2. There is a certain difference in the position of the calibration thermocouple 104 and the wafer, and it cannot fully represent the wafer temperature. The current technical calibration accuracy is low.

[0049] 3. The existing technology requires that the furnace door 107 be provided with a hole for inserting the calibration thermocouple 104, which may easily lead to sealing problems and corrosion problems of the furnace door 107.

[0050] To address the problems existing in the prior art, this patent proposes a new temperature self-calibration method. This new temperature calibration tool can more accurately calibrate the temperature of the wafer inside the chamber. A program automatically calculates and processes the temperature measured by the thermocouple and repeatedly adjusts the compensation value. This improves automation and reduces labor costs. It also eliminates the need for openings in the furnace door 107, thus avoiding sealing and corrosion issues.

[0051] The present invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention may be implemented in various forms and is not limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present invention more thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0052] Example 1

[0053] Figure 2 A schematic diagram of a semiconductor thermal processing device according to an embodiment of the present invention is shown.

[0054] like Figure 2 As shown, a semiconductor heat treatment device includes:

[0055] A furnace body 1, a process tube 2 disposed in the furnace body 1, and a wafer boat 3 disposed in the process tube 2. The wafer boat 3 is provided with multiple wafer placement areas along the axial direction of the process tube 2, and each wafer placement area can place multiple wafers 4 to be processed;

[0056] An internal temperature measuring element 5 is arranged at the inner edge of the process tube 2 along the axial direction of the process tube 2. A plurality of temperature measuring points 7 are spaced apart from one end of the internal temperature measuring element 5 to the other end. Each temperature measuring point 7 corresponds to a wafer placement area. Each wafer placement area is used to place a temperature measuring wafer 8 and a wafer 4 to be processed. A wafer temperature measuring element 9 is provided on the temperature measuring wafer 8.

[0057] The control unit, the internal temperature measuring component 5 and the wafer temperature measuring component 9 are respectively connected to the control unit, and the control unit is used to calibrate the temperature of the corresponding temperature measuring point 7 on the internal temperature measuring component 5 according to the temperature of the wafer temperature measuring component 9 so that the temperature of the temperature measuring wafer 8 is equal to the set temperature.

[0058] In this embodiment, a plurality of external temperature measuring elements 6 may be further included. The plurality of external temperature measuring elements 6 are spaced apart on the outer wall of the furnace body 1 . Each external temperature measuring element 6 is positioned opposite to a temperature measuring point 7 on the internal temperature measuring element 5 . The external temperature measuring elements 6 are connected to the control unit.

[0059] The control unit is further configured to perform temperature calibration on the corresponding external temperature measuring element 6 according to the temperature of the calibrated internal temperature measuring element 5 .

[0060] In this embodiment, the wafer temperature measuring element 9 is welded to the temperature measuring wafer 8. Preferably, the temperature measuring wafer 8 is located in the center of the corresponding wafer placement area and opposite a temperature measuring point 7 of the internal temperature measuring element 5. The internal temperature measuring element 5, the external temperature measuring element 6, and the wafer temperature measuring element 9 are all thermocouples. The process tube 2 can be a quartz tube, and the wafer boat 3 can be a quartz boat.

[0061] Specifically, by setting a wafer temperature measuring element 9 on the temperature measuring wafer 8, during the process, the temperature of the temperature measuring wafer 8 can be directly obtained through the wafer temperature measuring element 9, which is equivalent to obtaining the temperature of the wafer 4 to be processed in the wafer placement area where the temperature measuring wafer 8 is located, and the temperature of the temperature measuring wafer 8 is equal to the set temperature. Based on the multiple temperature measuring wafers 8, each temperature measuring point 7 on the internal temperature measuring element 5 corresponding to different wafer placement areas is calibrated, so that the temperature of each temperature measuring point 7 is equal to the set temperature. Since the internal temperature measuring element 5 is set along the axial direction of the process tube 2 and the temperature measuring points 7 are spaced apart on the internal temperature measuring element 5, the temperature calibration of the heat treatment equipment in its axial direction can be achieved. Based on the temperature of the temperature measuring point 7 of the calibrated internal temperature measuring element 5, the temperature of the corresponding external temperature measuring element 6 is calibrated, thereby achieving radial temperature calibration of the equipment from the inside to the outside.

[0062] This embodiment of semiconductor heat treatment equipment utilizes a new temperature calibration tool, a temperature measurement wafer 8. Temperature measurement points, formed by a wafer temperature measurement element 9 welded onto the wafer, provide direct feedback on the temperature of the wafer being measured. Temperature measurement wafer 8 can be placed on wafer boat 3, where standard wafers reside, to accurately measure the temperature of standard wafers. Compared to existing technologies, this eliminates the need for a separate, vertically movable thermocouple for temperature calibration, nor does it require a pre-recorded hole in the furnace door 10.

[0063] Example 2

[0064] Figure 3 A flowchart of the steps of a temperature automatic calibration method according to an embodiment of the present invention is shown.

[0065] like Figure 3 As shown, a temperature self-calibration method is applied to the semiconductor heat treatment equipment of Example 1, and the method includes: performing the following steps by a control unit:

[0066] Step S101: Obtain the temperature of the temperature measuring wafer 8 in the current cycle through the wafer temperature measuring element 9, calculate the temperature compensation value of a temperature measuring point 7 on the internal temperature measuring element 5 opposite to the temperature measuring wafer 8 based on the temperature of the temperature measuring wafer 8 and the set temperature required by the process, and calibrate the temperature of the temperature measuring point 7 based on the temperature compensation value;

[0067] In a specific application scenario, in this step, the temperature compensation value of the temperature measuring point 7 is calculated by the following formula:

[0068] Offset(t)=Offset(t-1)–P×(Set–TCWafer(t-1)) (1)

[0069] Among them, Offset(t) is the temperature compensation value of the temperature measurement point 7 in the t cycle, Offset(t-1) is the temperature compensation value of the temperature measurement point 7 in the t-1 cycle, Set is the set temperature required by the process, TCWafer(t-1) is the temperature of the temperature measurement wafer 8 in the t-1 cycle, and P is the influencing factor between the wafer temperature and the internal temperature measuring component 5.

[0070] The impact factor P is a value that can be tested on the basis of existing hardware, and is related to the structure of the furnace body 1 or the thermal conductivity of the platform. For example, if the internal temperature measuring component 5 is set to decrease by 1°C and the temperature of the temperature measuring wafer 8 is reduced by X°C, then the impact factor P = X / 1; the P value in this embodiment can be set to 1, which means that if the internal temperature measuring component 5 changes by 1°C, the temperature of the temperature measuring wafer 8 will change by 1°C.

[0071] Furthermore, the temperature at the temperature measuring point 7 is calibrated using the following formula:

[0072] Inner(t) *=Inner(t)+Offset(t) (2)

[0073] Among them, Inner(t) * is the temperature value of the temperature measurement point 7 in the t period after calibration, Inner(t) is the temperature value of the temperature measurement point 7 in the t period, Offset(t) is the temperature compensation value of the temperature measurement point 7 in the t period, Offset(0) is the temperature compensation value of the starting period, and Offset(0)=0.

[0074] In the above specific application scenario, before executing step S101 , the temperature measuring wafer 8 needs to be placed on the quartz boat where the wafers are located, and the temperature measuring wafer 8 needs to be placed at the corresponding position in the center of each wafer placement area on the wafer boat 3 .

[0075] Step S102: determining whether the temperature of the temperature measuring wafer 8 is stable; if so, executing step S103; otherwise, stabilizing the temperature of the temperature measuring wafer 8 through temperature control, executing step S103;

[0076] In this step, determining whether the temperature of the temperature measuring wafer 8 is stable includes:

[0077] The temperature variation range of the temperature measuring wafer 8 within a set time is collected by the wafer temperature measuring component 9. If the temperature variation is less than the set temperature variation range, it is determined that the temperature of the temperature measuring wafer 8 is stable.

[0078] The method of stabilizing the temperature of the temperature measuring wafer 8 by temperature control includes:

[0079] The temperature of the temperature measuring wafer 8 is stabilized by temperature control using a PID control method.

[0080] In the above-mentioned specific application scenario, the temperature calibration index can be defined as Spec, and the user defines the specific value and sets it in the program parameter setting interface, that is, the temperature calibration requirement is -Spec<=Set-TCWafer(t)<=Spec. After each adjustment of the compensation value Offset, it is necessary to judge whether the temperature of the temperature measuring wafer 8 is stable. The judgment method is: if the difference between the maximum and minimum temperatures of the temperature measuring wafer 8 within a period of time (for example, 30 minutes) is less than the value set by the user in the program parameter setting interface (for example, 0.6°C), it means that the temperature has stabilized. Otherwise, it is judged until the temperature control PID (existing technology) automatically adjusts to meet the temperature stability judgment condition. If the PID adjustment cannot achieve temperature regulation, it is necessary to manually modify the PID parameters or the temperature stability judgment condition. In the specific implementation process, it can be judged every 1 minute whether the difference between the maximum and minimum temperatures of the temperature measuring wafer 8 in the last 30 minutes is less than the value set by the user in the program parameter setting interface. If it is met, the judgment output of the temperature stability signal is interrupted. Otherwise, the judgment is continued until the temperature stability condition is met.

[0081] Step S103: determining whether a first difference between the set temperature and the temperature of the temperature measuring wafer 8 is within a preset difference range; if so, completing the temperature calibration of the temperature measuring point 7; otherwise, taking the next cycle as the current cycle and returning to step S101 to continue calibrating the temperature of the temperature measuring point;

[0082] In the above specific application scenario, if the initial time t=0, the set temperature value Set is 400°C, the corrected value Inner of the temperature measuring point 7 on the internal temperature measuring element 5 is *(0) is equal to the set value of 400°C, and the initial compensation value Offset(0) is 0. Then, according to formula (2), the temperature Inner(0) of the initial temperature measuring point 7 on the internal temperature measuring element 5 is 400°C, and the temperature TCWafer(0) measured by the temperature measuring wafer 8 is 410°C. Let the influence factor P between the wafer temperature and the internal temperature measuring element 5 be 1, and let the temperature calibration index Spec be 0.5°C. Assuming that the judgment index of wafer temperature stability is Range<0.6°C within 30 minutes, then after the initial wafer temperature stabilizes, Set-TCWafer(0)=-10°C, which does not meet the calibration index range of -0.5°C to 0.5°C. The compensation value Offset(0) needs to be corrected. According to formula (1), Offset(1)=0-1×(-10)=10. Then, according to formula (2), after the temperature stabilizes in the next cycle, the temperature Inner(1) of the temperature measuring point 7 on the internal temperature measuring element 5 should be equal to 390°C. This temperature is 10°C lower than the temperature Inner(0) of the initial temperature measuring point 7 on the internal temperature measuring component 5. Since the influence factor P between the wafer temperature and the internal temperature measuring component 5 is 1, the wafer temperature will also drop by about 10°C. Due to the error, if the wafer temperature still does not meet the index in the next cycle, a compensation value will be recalculated based on the difference between the new temperature of the temperature measuring wafer 8 and the set value, and the difference between the temperature measuring wafer 8 and the set value will be gradually reduced until the calibration target of the temperature of the corresponding temperature measuring point on the internal temperature measuring component 5 is reached.

[0083] In this embodiment, after executing step S103 and completing the temperature calibration of the internal temperature measuring component 5, the method further includes:

[0084] Step S104: calculating a second difference between the temperature of the temperature measuring point 7 and the temperature of an external temperature measuring component 6 opposite to the temperature measuring point 7, and calibrating the temperature of the external temperature measuring component 6 based on the second difference.

[0085] In this step, the temperature of the external temperature measuring element 6 is calibrated using the following formula:

[0086] Outer(t) * =Outer(t)+Profile+Offset(t) (3)

[0087] Among them, Outer(t) * is the temperature value of the external temperature measuring element 6 after calibration in period t, Profile is the temperature difference between the calibrated temperature measuring point 7 and the external temperature measuring element 6, and Offset(t) is the temperature compensation value of the temperature measuring point 7 in period t.

[0088] In the above specific application scenario, after the calibration criteria are met, the temperature difference Profile between temperature measuring point 7 on internal temperature measuring element 5 and external temperature measuring element 6 is calculated after the current temperature is finally stabilized. Based on formula (3), the temperature calibration of temperature measuring point 7 and external temperature measuring element 6 in the radial direction of the furnace tube equipment is completed. In summary, the temperature calibration has been completed for the current temperature (400°C), and the temperature setpoint Set can be changed to perform the next temperature calibration.

[0089] By repeating steps S101 - S104 , the temperature calibration of other temperature measuring points 7 on the internal temperature measuring element 5 and the external temperature measuring element 6 can be completed.

[0090] In the above specific application scenario, the wafer placement area on the heat treatment equipment or the wafer boat 3 can be divided into three sections: upper, middle and lower. Each section adopts the same temperature calibration procedure of steps S101-S104, and is calibrated at the same time. The internal temperature measuring component 5 has three temperature measuring points 7 at the upper, middle and lower positions corresponding to the internal temperature measuring component 5, and there is an external temperature measuring component 6 at the upper, middle and lower positions of the furnace body 1. Therefore, it is necessary to place a temperature measuring wafer 8 at the height corresponding to the upper, middle and lower temperature measuring points 7 of the internal temperature measuring component 5 in the chamber, and the upper temperature measuring wafer 8 is calibrated with the temperature measuring point 7 on the upper part of the internal temperature measuring component 5 and the external temperature measuring component 6 on the upper part of the furnace body 1. The lateral temperature calibration of the upper part of the body 1 is carried out; the lateral temperature calibration of the middle part of the furnace body 1 is carried out between the middle temperature measuring wafer 8 and the middle temperature measuring point 7 of the internal temperature measuring component 5 and the external temperature measuring component 6 in the middle of the furnace body 1; the lateral temperature calibration of the upper part of the furnace body 1 is carried out between the lower temperature measuring wafer 8 and the lower temperature measuring point 7 of the internal temperature measuring component 5 and the external temperature measuring component 6 in the lower part of the furnace body 1; when the upper, middle and lower sections are calibrated respectively, the temperature measuring wafers 8 of the upper, middle and lower sections are all equal to the set temperature, so that the upper, middle and lower temperatures in the chamber are all equal to the set temperature, that is, this method does not require separate calibration of the upper, middle and lower temperatures in the chamber.

[0091] It should be noted that the method of this embodiment can be implemented by designing a corresponding computer program and executing the program through a control unit.

[0092] In summary, the temperature measuring wafer 8 used in the present invention can replace the wafer temperature more accurately, and can automatically adjust the compensation value. Compared with the existing technology, it no longer requires manual modification, has a high degree of automation, and reduces the uncertainty of human operation. It can combine the radial temperature calibration and axial temperature calibration along the furnace tube equipment in the existing technology into one, and has higher accuracy, saving temperature calibration time. At the same time, it is no longer necessary to open a hole in the furnace door 10, avoiding the sealing and corrosion problems of the special hole for temperature calibration of the furnace door 10 in the existing technology.

[0093] While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A semiconductor heat treatment device, characterized in that: include: A furnace body, a process tube disposed in the furnace body, and a wafer boat disposed in the process tube, wherein the wafer boat is provided with a plurality of wafer placement areas along the axial direction of the process tube, and each of the wafer placement areas can place a plurality of wafers to be processed; An internal temperature measuring element is arranged at the inner edge of the process tube along the axial direction of the process tube, and a plurality of temperature measuring points are spaced apart from one end to the other end of the internal temperature measuring element, each of the temperature measuring points corresponds to one of the wafer placement areas, and each of the wafer placement areas is used to place a temperature measuring wafer and a wafer to be processed, and a wafer temperature measuring element is provided on the temperature measuring wafer; a control unit, the internal temperature measuring element and the wafer temperature measuring element being connected to the control unit respectively, the control unit being configured to calibrate the temperature of the corresponding temperature measuring point on the internal temperature measuring element according to the temperature of the wafer temperature measuring element so that the temperature of the temperature measuring wafer is equal to the set temperature; The control unit is specifically configured to perform the following steps: Step S1: obtaining the temperature of the temperature measuring wafer in the current cycle through the wafer temperature measuring element, calculating a temperature compensation value of a temperature measuring point on the internal temperature measuring element opposite to the temperature measuring wafer based on the temperature of the temperature measuring wafer and the set temperature required by the process, and calibrating the temperature of the temperature measuring point based on the temperature compensation value; wherein the temperature compensation value of the temperature measuring point is calculated by the following formula: Offset(t)=Offset(t-1)–P×(Set–TCWafer(t-1)) Wherein, Offset(t) is the temperature compensation value of the temperature measurement point in period t, Offset(t-1) is the temperature compensation value of the temperature measurement point in period t-1, Set is the set temperature required by the process, TCWafer(t-1) is the temperature of the temperature measurement wafer obtained in period t-1, and P is the influence factor between the temperature of the temperature measurement wafer and the internal temperature measurement component; Step S2: determining whether the temperature of the temperature measuring wafer is stable in the current cycle; if so, executing step S3; otherwise, stabilizing the temperature of the temperature measuring wafer through temperature control, and executing step S3; Step S3: Determine whether the first difference between the set temperature and the temperature of the temperature measuring wafer is within a preset difference range. If so, complete the temperature calibration of the temperature measuring point. Otherwise, take the next cycle as the current cycle and return to execute step S1 to continue calibrating the temperature of the temperature measuring point.

2. The semiconductor heat treatment equipment according to claim 1, characterized in that It also includes a plurality of external temperature measuring elements, which are spaced apart on the outer wall of the furnace body, each of which is located opposite to a temperature measuring point on the internal temperature measuring element, and the external temperature measuring elements are connected to the control unit; The control unit is further configured to perform temperature calibration on the corresponding external temperature measuring component according to the calibrated temperature of the internal temperature measuring component.

3. The semiconductor heat treatment equipment according to claim 1, characterized in that The wafer temperature measuring component is welded on the temperature measuring wafer.

4. The semiconductor heat treatment equipment according to claim 1, wherein The temperature measuring wafer is located in the middle of the corresponding wafer placement area and is opposite to a temperature measuring point of the internal temperature measuring component.

5. A temperature self-calibration method for semiconductor heat treatment equipment according to any one of claims 1 to 4, characterized in that: The method comprises: executing the following steps by the control unit: Step S1: obtaining the temperature of the temperature measuring wafer in the current cycle through the wafer temperature measuring element, calculating a temperature compensation value of a temperature measuring point on the internal temperature measuring element opposite to the temperature measuring wafer based on the temperature of the temperature measuring wafer and the set temperature required by the process, and calibrating the temperature of the temperature measuring point based on the temperature compensation value; wherein the temperature compensation value of the temperature measuring point is calculated by the following formula: Offset(t)=Offset(t-1)–P×(Set–TCWafer(t-1)) Wherein, Offset(t) is the temperature compensation value of the temperature measurement point in period t, Offset(t-1) is the temperature compensation value of the temperature measurement point in period t-1, Set is the set temperature required by the process, TCWafer(t-1) is the temperature of the temperature measurement wafer obtained in period t-1, and P is the influence factor between the temperature of the temperature measurement wafer and the internal temperature measurement component; Step S2: determining whether the temperature of the temperature measuring wafer is stable in the current cycle; if so, executing step S3; otherwise, stabilizing the temperature of the temperature measuring wafer through temperature control, and executing step S3; Step S3: Determine whether the first difference between the set temperature and the temperature of the temperature measuring wafer is within a preset difference range. If so, complete the temperature calibration of the temperature measuring point. Otherwise, take the next cycle as the current cycle and return to execute step S1 to continue calibrating the temperature of the temperature measuring point.

6. The temperature self-calibration method according to claim 5, characterized in that: After executing step S3 and completing the temperature calibration of the internal temperature measuring component, the method further includes: Step S4: calculating a second difference between the temperature of the temperature measuring point and the temperature of an external temperature measuring component opposite to the temperature measuring point, and calibrating the temperature of the external temperature measuring component based on the second difference.

7. The temperature self-calibration method according to claim 5, characterized in that: In step S1, the temperature of the temperature measuring point is calibrated using the following formula: Inner(t) * =Inner(t)+Offset(t) Among them, Inner(t) * is the temperature value of the temperature measuring point on the internal temperature measuring component in the t period after calibration, Inner(t) is the temperature value of the temperature measuring point in the t period, Offset(t) is the temperature compensation value of the temperature measuring point in the t period, Offset(0) is the temperature compensation value of the starting period, and Offset(0)=0.

8. The temperature self-calibration method according to claim 6, characterized in that: In step S4, the temperature of the external temperature measuring element is calibrated using the following formula: Outer(t) * =Outer(t)+Profile+Offset(t) Among them, Outer(t) * is the temperature value of the external temperature measuring element after calibration in period t, Profile is the temperature difference between the calibrated temperature measuring point and the corresponding external temperature measuring element, and Offset(t) is the temperature compensation value of the temperature measuring point in period t.

9. The temperature self-calibration method according to claim 5, characterized in that: In step S2, determining whether the temperature of the temperature-measuring wafer is stable in the current cycle includes: The temperature variation range of the temperature measuring wafer in the current cycle is collected by the wafer temperature measuring component. If the temperature variation range is smaller than the set temperature variation range, it is determined that the temperature of the temperature measuring wafer is stable.

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