Temperature control method for semiconductor heating apparatus, and temperature control system

Abstract

The present invention provides a temperature control method for a semiconductor heating apparatus, and a temperature control apparatus. The temperature control method comprises: step S1, on the basis of a first present temperature, a first present power, a first target temperature, and a correspondence between a theoretical power and a temperature, performing first temperature rise control on a semiconductor heating apparatus, and calibrating adjustment parameters for the first temperature rise control; and step S2, on the basis of a second present temperature, a second present power, a second target temperature, the adjustment parameters for the first temperature rise control, and the correspondence between a theoretical power and a temperature, continuing to perform second temperature rise control on the semiconductor heating apparatus, wherein the correspondence between a theoretical power and a temperature is obtained by means of performing fitting processing on process data of steady-state stages corresponding to different preset temperatures, which process data is acquired by performing preheating control on the semiconductor heating apparatus at different preset temperatures, so that using the adjustment parameters calibrated in S1 in the temperature rise process in step S2 can realize a stable temperature rise, and saves on the parameter calibration cost.

Description

Temperature control method and temperature control system for semiconductor heating device Technical Field

[0001] The present invention relates to the technical field of semiconductor equipment, and in particular to a temperature control method and a temperature control system for a semiconductor heating device. Background Art

[0002] Semiconductor processing equipment, such as chemical vapor deposition (CVD) equipment, utilizes vapor-phase chemical reactions to deposit thin solid films onto substrate surfaces. To ensure uniformity and high film quality, CVD reactions place high demands on temperature control. After reaching the target process temperature, the temperature must quickly reach equilibrium and remain stable.

[0003] For heating models, the relationship between temperature and power is nonlinear. To achieve stable heating control, heating control requires converting this nonlinear relationship between temperature and power into a linear one before performing control. For example, PID control is a type of linear control. This control variable is formed by linearly combining the proportional (P), integral (I), and differential (D) of the deviation between a given value and the actual output value to control the controlled object. Figure 1 shows the temperature-time relationship curve under conventional PID control. With the target temperature as the setpoint (SV), after heating to the maximum overshoot value, the PID adjustment stage repeatedly adjusts the temperature until the steady-state deviation (EV) approaches zero, as shown in Figure 1, achieving the steady-state stage at the target temperature. However, conventional PID control presents the following problems: Due to the nonlinear relationship between temperature and power, different control parameters are required for different temperature ranges, necessitating repeated recalibration of the control parameters, which hinders the stable achievement of temperature equilibrium.

[0004] It should be noted that the above introduction to the technical background is merely intended to provide a clear and complete description of the technical solutions of this application and facilitate understanding by those skilled in the art. Simply because these solutions are described in the background technology section of this application, it should not be assumed that the above technical solutions are well known to those skilled in the art.

[0005] Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a temperature control method for a semiconductor heating device and a temperature control system for implementing the method, which saves the control parameter calibration step and is conducive to the smooth realization of the temperature equilibrium state.

[0007] To achieve the above object, the temperature control method provided by the present invention comprises the following steps:

[0008] S0: Provides the corresponding relationship between theoretical power and temperature;

[0009] The correspondence between the theoretical power and the temperature is obtained by performing preheating control on the semiconductor heating device at different preset temperatures as preset target temperatures and performing fitting processing on the temperature data and power data of the steady-state phase corresponding to the different preset temperatures obtained;

[0010] S1: Obtaining a first current temperature and a first current power, performing a first temperature rise control on the semiconductor heating device according to the first current temperature, the first current power, a first target temperature, and a correspondence between the theoretical power and temperature, and calibrating an adjustment parameter of the first temperature rise control;

[0011] S2: Obtain a second current temperature and a second current power, and perform a second temperature rise control on the semiconductor heating device according to the second current temperature, the second current power, the second target temperature, the adjustment parameters of the first temperature rise control, and the correspondence between the theoretical power and the temperature.

[0012] The beneficial effect of the temperature control method of the present invention is that the corresponding relationship between the theoretical power and the temperature is obtained by preheating the semiconductor heating device with different preset temperatures as the preset target temperature and fitting the temperature data and power data of the steady-state stage corresponding to the different preset temperatures obtained, so that after the first temperature rise control is performed in step S0 and the adjustment parameters of the first temperature rise control are calibrated, the subsequent temperature rise control does not need to recalibrate the adjustment parameters, and the temperature balance control process of the temperature rise control process can be smoothly implemented.

[0013] Optionally, in step S1, the corresponding relationship between the theoretical power and temperature is: P theory =a0+a1T+a2T 2 +a3T 3 +a4T 4

[0014] Among them, P theory is the theoretical power, T is the temperature, and a0, a1, a2, a3 and a4 are constants.

[0015] Optionally, in step S0, the temperature control method according to claim 1 is characterized in that, in step S0, the step of providing the corresponding relationship between theoretical power and temperature includes:

[0016] Preheating the semiconductor heating device at N different preset temperatures as preset target temperatures until the device reaches a steady state corresponding to each of the different preset temperatures, where N is a positive integer greater than or equal to 4;

[0017] Obtaining the steady-state temperature and the corresponding steady-state power in each steady-state stage;

[0018] The fitting process is performed based on the acquired N groups of steady-state temperatures and corresponding steady-state power data groups to obtain the corresponding relationship between the theoretical power and temperature.

[0019] Optionally, the preheating control includes current temperature rise control.

[0020] Optionally, in step S0, the step of performing preheating control on the semiconductor heating device at N different preset temperatures as the preset target temperature includes:

[0021] First, the semiconductor heating device is preheated in the Mth stage with the Mth preset temperature as the preset target temperature, and after determining based on the acquired temperature information whether the temperature fluctuation satisfies the temperature steady-state condition, it is determined based on the acquired power information whether the power fluctuation satisfies the power steady-state condition to reach the corresponding steady-state stage;

[0022] Then, the semiconductor heating device is subjected to the M+1th stage of preheating control with the M+1th preset temperature as the preset target temperature;

[0023] The M+1th preset temperature is greater than the Mth preset temperature, where M is a positive integer greater than or equal to 1 and less than N.

[0024] Optionally, the difference between the M+1th preset temperature and the Mth preset temperature is not less than 50 degrees Celsius and not more than 100 degrees Celsius.

[0025] Optionally, the step of determining whether the temperature fluctuation meets the temperature steady-state condition based on the acquired temperature information and then determining whether the power fluctuation meets the power steady-state condition based on the acquired power information includes:

[0026] Acquiring each real-time temperature of the semiconductor heating device within a certain time period starting from time node t1 and calculating the corresponding average temperature, and determining that the difference between each real-time temperature and the average temperature is within a temperature fluctuation threshold range to meet the temperature steady-state condition;

[0027] The real-time power of the semiconductor heating device in continuous time intervals starting from the time node t1 is obtained and the average power corresponding to each time interval is calculated, and the power fluctuation percentage between the average powers corresponding to adjacent time intervals is determined to be within the power fluctuation threshold range to meet the power steady-state condition.

[0028] Optionally, the temperature fluctuation threshold range is -0.1 degrees Celsius to +0.1 degrees Celsius, the certain time period is not less than 2 minutes, the time interval is not less than 120 seconds, and the power fluctuation threshold range is -10% to +10%.

[0029] Optionally, the step of obtaining the steady-state temperature and the corresponding steady-state power in each steady-state stage includes:

[0030] Obtaining each real-time steady-state temperature in a selected time period under the steady-state stage corresponding to the preset temperature, or obtaining each real-time steady-state temperature in the selected time period and calculating the corresponding average steady-state temperature;

[0031] Either the average steady-state temperature or any of the real-time steady-state temperatures is selected as the steady-state temperature.

[0032] Optionally, the step of obtaining the steady-state temperature and the corresponding steady-state power in each steady-state stage includes: selecting the preset temperature as the steady-state temperature.

[0033] Optionally, the step of obtaining the steady-state temperature and the corresponding steady-state power in each steady-state stage includes:

[0034] Obtaining each real-time steady-state power in a selected time period under the steady-state stage corresponding to the preset temperature, or obtaining each real-time steady-state power in the selected time period and calculating the corresponding average steady-state power;

[0035] Either the average steady-state power or any of the real-time steady-state powers is selected as the steady-state power.

[0036] Optionally, at least one of the different preset temperatures is higher than the first target temperature.

[0037] Optionally, in step S1, the step of performing a first temperature increase control on the semiconductor heating device according to the first current temperature, the first current power, the first target temperature, and the correspondence between the theoretical power and the temperature includes:

[0038] Obtaining a first current theoretical power according to the first current temperature and the corresponding relationship between the theoretical power and temperature;

[0039] The semiconductor heating device is subjected to PID temperature rise control according to the first current power and the first current theoretical power to output a first control current instruction to drive the semiconductor heating device to heat up, and the adjustment parameter of the first temperature rise control is calibrated as k p 、k i and k d .

[0040] Optionally, the step of continuing to perform a second temperature increase control on the semiconductor heating device according to the second current temperature, the second current power, the second target temperature, the adjustment parameter of the first temperature increase control, and the corresponding relationship equation between the theoretical power and the temperature includes:

[0041] Obtaining a second current theoretical power according to the second current temperature and the corresponding relationship between the theoretical power and temperature;

[0042] According to the second current power, the first current theoretical power and k p 、k i and k d Perform PID temperature rise control on the semiconductor heating device to output a second control current instruction to drive the semiconductor heating device to heat up

[0043] Optionally, in step S1 and step S2, the step of performing the PID temperature rising control on the semiconductor heating device includes calculating the control current using the following formula:

[0044] Among them, I control To control the current, k p 、k i and k d They are proportional regulation constant, integral regulation constant and differential regulation constant respectively;

[0045] In step S1, err(P) is the difference between the first current power and the first current theoretical power;

[0046] In step S2, err(P) is the difference between the second current power and the second current theoretical power.

[0047] To achieve the above object, the present invention further provides a temperature control system, comprising:

[0048] The semiconductor heating device heats up in response to the driving of the power control unit;

[0049] a temperature measuring unit, for acquiring and transmitting the current temperature of the semiconductor heating device;

[0050] The power control unit drives the semiconductor heating device in response to the control instruction, and exchanges information with the main control unit to transmit the current power at the current temperature;

[0051] The main control unit exchanges information with the temperature measurement unit and the power control unit, generates a control instruction according to the current temperature, the current power, the target temperature, and the correspondence between the theoretical power and the temperature, and transmits the control instruction to the power control unit;

[0052] Wherein, when performing temperature rise control based on the control instruction, the adjustment parameters of the temperature rise control are calibrated, and the subsequent temperature rise control in different stages is executed with the calibrated adjustment parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] FIG. 1 is a schematic diagram showing a corresponding relationship curve between temperature and time obtained by conventional PID control of a semiconductor device in the prior art.

[0054] FIG2 is a structural block diagram of a temperature control system according to an embodiment of the present invention.

[0055] FIG3 is a schematic flow chart showing a temperature control method for a semiconductor heating device according to an embodiment of the present invention.

[0056] FIG. 4 is a schematic diagram showing a curve of the corresponding relationship between temperature and time obtained during the preheating control process according to an embodiment of the present invention.

[0057] FIG5 shows a temperature rise curve diagram of a semiconductor device in an embodiment of the present invention obtained by using the temperature control method of the present invention.

[0058] FIG. 6 shows a temperature rise curve diagram of the semiconductor device according to an embodiment of the present invention obtained by using a conventional PID control method. DETAILED DESCRIPTION

[0059] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0060] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0061] The temperature control system provided by the embodiment of the present invention, with reference to FIG2 , includes a semiconductor heating device 1, a temperature measuring unit 2, a main control unit 3, and a power control unit 4. The temperature measuring unit 2 obtains and transmits the current temperature of the semiconductor heating device 1, and the main control unit 3 exchanges information with the temperature measuring unit 2 and the power control unit 4. The main control unit 3 generates a control instruction based on the current temperature, the target temperature, and the correspondence between the theoretical power and the temperature, and transmits the control instruction to the power control unit 4; the power control unit 4 drives the semiconductor heating device 1 in response to the control instruction, and the semiconductor heating device 1 heats up in response to the control instruction of the power control unit 4. The power control unit 4 exchanges information with the main control unit 3 to provide the main control unit 3 with the current power corresponding to the current temperature. In particular, when performing temperature control based on the control instruction, the adjustment parameters of the temperature control are calibrated, and the subsequent temperature control in different stages is performed with the calibrated adjustment parameters, thereby saving the calibration step of the adjustment parameters and facilitating the smooth realization of the temperature equilibrium state.

[0062] The type of semiconductor heating device 1 of this embodiment is not limited, as long as it can generate heat in response to current control instructions. The heated object includes, but is not limited to, a carrier (e.g., a graphite disk) used to support the substrate, a reaction chamber, etc. In some specific embodiments, the semiconductor heating device 1 is disposed below the carrier to heat the carrier; in some specific embodiments, the semiconductor heating device 1 is disposed around the side wall of the reaction chamber to heat the space within the reaction chamber.

[0063] In some embodiments, the main control unit 3 is electrically connected to the temperature measurement unit 2 and the power control unit 4 respectively.

[0064] In some embodiments, the power control unit 4 is electrically connected to the semiconductor heating device 1. In some specific embodiments, the power control unit 4 is a power supply unit (PSU), which outputs a selected voltage and a controlled current. This is highly safe for chemical vapor deposition, especially at high temperatures.

[0065] In some specific embodiments, the semiconductor heating device 1 is a resistance wire heater or a graphite heater.

[0066] In some specific embodiments, the temperature measuring unit 2 is a non-contact thermocouple, and its detection end is close to the semiconductor heating device 1 to obtain the current temperature of the semiconductor heating device 1 .

[0067] In some specific embodiments, the temperature measuring unit 2 is a contact thermocouple.

[0068] In some embodiments, the main control unit 3 stores the correspondence between theoretical power and temperature, and stores the data of information exchange between the temperature measurement unit 2 and the power control unit 4. In some specific embodiments, the main control unit 3 is an industrial computer.

[0069] The embodiment of the present invention also provides a temperature control method implemented by using the above temperature control system. Referring to FIG3 , the method includes the following steps:

[0070] S0, provides the corresponding relationship between theoretical power and temperature;

[0071] The correspondence between the theoretical power and the temperature is obtained by performing preheating control on the semiconductor heating device at different preset temperatures as preset target temperatures and performing fitting processing on the temperature data and power data of the steady-state phase corresponding to the different preset temperatures obtained;

[0072] S1: Obtaining a first current temperature and a first current power, performing a first temperature rise control on the semiconductor heating device according to the first current temperature, the first current power, a first target temperature, and a correspondence between the theoretical power and temperature, and calibrating an adjustment parameter of the first temperature rise control;

[0073] S2: Obtain a second current temperature and a second current power, and continue to perform a second temperature rise control on the semiconductor heating device according to the second current temperature, the second current power, the second target temperature, the adjustment parameters of the first temperature rise control, and the correspondence between the theoretical power and the temperature.

[0074] In step S0 of the embodiment of the present invention, the theoretical power-temperature correspondence is obtained by performing preheating control on the semiconductor heating device at different preset temperatures as preset target temperatures and fitting the temperature and power data obtained during the steady-state phase corresponding to the different preset temperatures. Because the relationship between temperature and power of the heating device is not linear, preheating control is performed at a specific preset temperature as the preset target temperature until the corresponding steady-state phase is reached. During this steady-state phase, process data such as temperature and power are very close to the target temperature and power. Obtaining an appropriate theoretical power-temperature correspondence by fitting this data will more closely meet the requirements of linear control.

[0075] In some embodiments of the present invention, in step S0, the step of providing the corresponding relationship between theoretical power and temperature includes:

[0076] S01, performing preheating control on the semiconductor heating device at N different preset temperatures as preset target temperatures until the steady-state stages corresponding to the different preset temperatures are reached respectively;

[0077] S02: Obtaining the steady-state temperature and the corresponding steady-state power in each steady-state stage;

[0078] S03: performing the fitting process according to the acquired N groups of steady-state temperatures and corresponding steady-state power data groups to obtain the corresponding relationship between the theoretical power and temperature.

[0079] In step S01 of some embodiments, preheating control of the semiconductor heating device with N different preset temperatures as preset target temperatures includes: continuously preheating control of the semiconductor heating device, so that the semiconductor heating device undergoes a first stage of preheating and temperature increase until it reaches a steady-state stage corresponding to the first preset temperature, and then continues to perform a second stage of preheating and temperature increase until it reaches a steady-state stage corresponding to the second preset temperature, and so on until it reaches the steady-state stage corresponding to the Nth preset temperature.

[0080] With reference to FIG4 , the process of preheating control of the semiconductor heating device in the embodiment of the present invention is illustrated as follows: taking the first preset temperature T1 as the preset target temperature for preheating control as an example, after the temperature rises to the first overshoot temperature T1′ higher than T1 at the time node t0, the temperature control enters the steady-state stage so that the temperature is balanced within a certain range above and below T1 (i.e., the time period t0 to t2 is defined as the constant temperature stage of preheating control, and the purpose of this stage control is to achieve constant temperature control). During the balanced control process, the amplitude of the temperature oscillation from the time node t1 is within a certain steady-state interval, and the time period from t1 to t2 is the steady-state stage in the constant temperature stage. After reaching the steady-state stage corresponding to the first preset temperature T1, the temperature is continued to be raised with the second preset temperature T2 as the preset target temperature. For the specific stages of the temperature rise, refer to the description of the stages of the temperature rise with T1 as the preset target temperature, and no further details will be given here.

[0081] In some embodiments, in step S01, the step of performing preheating control on the semiconductor heating device at N different preset temperatures as the preset target temperature includes: first performing preheating control on the semiconductor heating device at the Mth preset temperature as the preset target temperature for the Mth stage, and then performing preheating control on the semiconductor heating device at the M+1th preset temperature as the preset target temperature for the M+1th stage, where M is a positive integer greater than or equal to 1 and less than N.

[0082] In some embodiments, the preheating control includes current ramp control.

[0083] In step S01 of some embodiments, the M+1th preset temperature is greater than the Mth preset temperature.

[0084] With reference to the structural block diagram of the temperature control system shown in FIG2 and the curve diagram of the corresponding relationship between temperature and time obtained during the preheating control process shown in FIG4 , the temperature control method of the semiconductor heating device in a specific embodiment of the present invention is introduced in detail: the main control unit 3 drives the semiconductor heating device 1 from room temperature to T1' which is slightly higher than the first preset temperature T1 by controlling the power control unit 4 according to the preset current heating program, and then performs balance control until the corresponding steady-state stage is reached; then the main control unit 3 continues to use the second preset temperature T2 as the preset target temperature, and according to the preset current heating program, controls the power control unit 4 to drive the semiconductor heating device 1 to continue to heat up to the corresponding overshoot temperature which is slightly higher than the second preset temperature T2, and then performs balance control until the corresponding steady-state stage is reached.

[0085] In step S01 of some embodiments, in order to avoid under-fitting problems in subsequent fitting processing, the difference between the M+1th preset temperature and the Mth preset temperature is controlled to be no higher than 100 degrees Celsius.

[0086] In step S01 of some embodiments, taking into account the overfitting phenomenon caused by too many parameters used for fitting, the corresponding relationship between the theoretical power and temperature obtained by the fitting process has poor generalization ability in the temperature rise control process and cannot quickly achieve steady-state equilibrium or even cannot achieve steady-state equilibrium, the difference between the M+1 preset temperature and the M preset temperature is controlled to be no less than 50 degrees Celsius.

[0087] Since it is necessary to obtain the process data of the steady-state stage corresponding to different preset temperatures from this step for fitting processing, in order to avoid underfitting due to too little data, it is preferred to control N to be a positive integer greater than or equal to 4.

[0088] In some specific embodiments, the first preset temperature is 500 degrees Celsius, the second preset temperature is 600 degrees Celsius, the third preset temperature is 700 degrees Celsius, and the fourth preset temperature is 800 degrees Celsius.

[0089] Since temperature balance is a prerequisite for power balance, if the temperature cannot reach the equilibrium state in the steady-state range, the power must be unbalanced. Therefore, in step S01 of some embodiments, the semiconductor heating device is first preheated in the Mth stage with the Mth preset temperature as the preset target temperature, and the temperature fluctuation is judged to meet the temperature steady-state condition based on the obtained temperature information, and then the power fluctuation is judged to meet the power steady-state condition based on the obtained power information to reach the corresponding steady-state stage; and then the semiconductor heating device is preheated in the M+1th stage with the M+1th preset temperature as the preset target temperature.

[0090] In step S01 of some embodiments, the steps of determining whether the temperature fluctuation meets the temperature steady-state condition based on the acquired temperature information and then determining whether the power fluctuation meets the power steady-state condition based on the acquired power information include: obtaining the real-time temperatures of the semiconductor heating device within a certain time period from the time node t1 and calculating the corresponding average temperature, and determining whether the difference between each real-time temperature and the average temperature is within the temperature fluctuation threshold range to meet the temperature steady-state condition.

[0091] Specifically, the semiconductor heating device 1 is preheated in the first stage according to the first preset temperature until it reaches the steady state corresponding to the first preset temperature T1. Then, the semiconductor heating device 1 is preheated in the second stage until it reaches the steady state corresponding to the second preset temperature T2. This process is repeated until the semiconductor heating device 1 is preheated in the Mth stage until it reaches the steady state corresponding to the Nth preset temperature.

[0092] The real-time temperature data and real-time power data in the above-mentioned staged preheating control process are sent to the main control unit 3 through the temperature measuring unit 2 and the power control unit 4 respectively. These real-time temperature data and real-time power data include the process data of the steady-state stage corresponding to different preset temperatures, that is, the real-time temperature and corresponding real-time power of the steady-state stage corresponding to each preset temperature.

[0093] 2 and 4 , the main control unit 3 controls the power control unit 4 to drive the semiconductor heating device 1 to perform the first balance control until the steady-state stage corresponding to the first preset temperature T1 is reached (i.e., the time period t1 to t2 in FIG4 ). The real-time temperatures in the time period t1 to t2 transmitted to the main control unit 3 by the temperature measuring unit 2 are T11, T12, T13, T14…T1n in chronological order, and the real-time powers corresponding to each sampling time node transmitted to the main control unit 3 by the power control unit 4 are P11, P12, P13…P1n respectively. The main control unit 3 calculates the average temperature in the time period t1 to t2 based on each real-time temperature as Ta, and performs a subtraction calculation on each real-time temperature and the average temperature Ta, for example, calculating ΔT1 = T11-Ta, ΔT2 = T12-Ta, ΔT3 = T13-Ta, ... ΔTn = T1n-Ta, and determines that the value of each ΔT is within the temperature fluctuation threshold range, and the steady-state duration (t2-t1) is not less than a certain time period, then it is determined that the temperature fluctuation condition has been met since the time node t1.

[0094] The specific temperature fluctuation threshold range and steady-state duration can be reasonably set according to the heating requirements of the process and the control accuracy of the semiconductor heating device itself. If the temperature fluctuation threshold range is too large and / or the steady-state duration is too short, for example, corresponding to the time period t0 to t1 shown in Figure 4, the temperature and power in this time period are unstable. If the fitting process is used to obtain the theoretical power and temperature correspondence to guide the temperature rise control, it will obviously bring significant errors. If the temperature fluctuation threshold range is too small and the temperature fluctuation conditions are set too strictly, the heating control accuracy of the semiconductor heating device itself makes it difficult to achieve the steady-state stage (for example, a long equilibrium control time is required) or even impossible to achieve (for example, the heating control accuracy requirement of the semiconductor itself is lower than the control requirement of the temperature fluctuation threshold).

[0095] In some embodiments, the temperature fluctuation threshold range is -0.1 degrees Celsius to +0.1 degrees Celsius, and the steady-state duration is not less than 2 minutes.

[0096] In step S0 of some embodiments, the step of determining whether the temperature fluctuation meets the temperature steady-state condition based on the acquired temperature information and then determining whether the power fluctuation meets the power steady-state condition based on the acquired power information also includes: obtaining the real-time power of the semiconductor heating device in continuous time intervals starting from the time node t1 and calculating the average power corresponding to each time interval, and determining whether the power fluctuation percentage between the average powers corresponding to adjacent time intervals is within the power fluctuation threshold range to meet the power steady-state condition.

[0097] Since the relationship between the real-time temperature and real-time power of the semiconductor heating device is nonlinear, and even when entering the steady-state stage between t1 and t2 shown in Figure 4, the change amplitude of the real-time power is much larger than the change amplitude of the real-time temperature, the judgment of the power balance condition is based on whether the power fluctuation percentage between the average power corresponding to adjacent time intervals is within the power fluctuation threshold range.

[0098] Referring to Figures 2 and 4 , it is determined that the temperature fluctuation condition has been met since time point t1. The power control unit 4 transmits the real-time steady-state power values ​​P11, P12, P13, ..., P1n, for the time period t1 to t2 to the main control unit 3. For example, the corresponding real-time steady-state power data set within a time interval is (P11, P12, P13, ..., P1n). These m power values ​​are averaged to obtain P1. Similarly, within each of the subsequent n-1 consecutive time intervals, the corresponding real-time steady-state power data sets sampled are averaged to obtain the following average powers P2, P3, P4, ..., Pn. The main control unit 3 sequentially calculates the adjacent average powers of the n average powers P1, P2, P3, ..., Pn to obtain a number of power fluctuation percentages. Taking the adjacent P1 and P2 as an example, the power fluctuation percentage is the percentage calculated as (P2-P1) / P1. The main control unit 3 determines that the power fluctuation percentages from the tp time node after the t1 time node to the t2 time node are within the power fluctuation threshold range, and then selects and / or processes data in the tp-t2 time period for fitting processing.

[0099] The specific power fluctuation threshold range and time interval can be appropriately set based on the heating process requirements and the control accuracy of the semiconductor heating device. If the power fluctuation threshold range is too large and / or the time interval is too short, the power will be unstable. Using this power fluctuation threshold to obtain a theoretical power-temperature relationship to guide temperature control will obviously result in significant errors. If the power fluctuation threshold range is too small and the power fluctuation conditions are set too strictly, the heating control accuracy of the semiconductor heating device will make it difficult or even impossible to achieve a steady-state state.

[0100] In some embodiments, the time interval is not less than 120 seconds, and the power fluctuation threshold range is -10% to +10%.

[0101] In step S02 of some embodiments, the step of obtaining the steady-state temperature and the corresponding steady-state power in each steady-state stage includes: obtaining the real-time steady-state temperatures in the selected time period under the steady-state stage corresponding to the preset temperature or obtaining the real-time steady-state temperatures in the selected time period and calculating the corresponding average steady-state temperature; selecting any one of the average steady-state temperature and any real-time steady-state temperature as the steady-state temperature.

[0102] In step S02 of some embodiments, the step of obtaining the steady-state temperature and the corresponding steady-state power in each steady-state stage includes: obtaining the real-time steady-state powers in the selected time period under the steady-state stage corresponding to the preset temperature, or obtaining the real-time steady-state powers in the selected time period and calculating the corresponding average steady-state power; selecting any one of the average steady-state power and any one of the real-time steady-state powers as the steady-state power.

[0103] In step S02 of some embodiments, the step of obtaining the steady-state temperature and the corresponding steady-state power in each steady-state stage includes: selecting the preset temperature as the steady-state temperature.

[0104] As described above, for the preheating control in the Mth stage, the temperature control in the steady-state time after the time node tp satisfies the temperature fluctuation condition and the power fluctuation condition. Then, the main control unit 3 selects the real-time steady-state temperatures (Tp1, Tp2, ..., Tpm) transmitted by the temperature measuring unit 2 after the time node tp, and the real-time steady-state powers (Pp1, Pp2, ..., Ppm) corresponding to the above-mentioned steady-state temperatures transmitted from the power control unit 4:

[0105] In some embodiments, the main control unit 3 selects any one temperature from (Tp1, Tp2, ..., Tpm) as the steady-state temperature Twm for subsequent fitting processing, and the steady-state power corresponding to the steady-state temperature is Pwm.

[0106] In some embodiments, the main control unit 3 uses the preset temperature of the Mth stage as the steady-state temperature, and uses the average power of (Pp1, Pp2...Ppm) as the corresponding steady-state power Pwm, or takes the average of any number of power values ​​in (Pp1, Pp2...Ppm) as the steady-state power Pwm.

[0107] In some embodiments, in some embodiments, the main control unit 3 selects any one temperature from (Tp1, Tp2...Tpm) as the steady-state temperature Tm for subsequent fitting processing, and uses the average power of (Pp1, Pp2...Ppm) as the corresponding steady-state power Pwm, or takes the average of any number of power values ​​in (Pp1, Pp2...Ppm) as the steady-state power Pwm.

[0108] In step S03 of some embodiments, N sets of corresponding data sets of steady-state temperature and steady-state power are obtained for the N stages of preheating control respectively through the aforementioned step S01, i.e., (Tw1, Pw1) obtained from the steady-state data of the first stage of preheating control, (Tw2, Pw2) obtained from the steady-state data of the second stage of preheating control, etc., and (Twn, Pwn) obtained from the steady-state data of the Nth stage of preheating control. Each set of data is substituted into the following equation for fitting processing to calculate constants a0, a1, a2, a3, and a4:

[0109] Thus, the corresponding relationship between theoretical power and temperature is obtained as follows: P theory =a0+a1T+a2T 2 +a3T 3 +a4T 4

[0110] Among them, P theory is the theoretical power, T is the temperature, and a0, a1, a2, a3 and a4 are constants.

[0111] In step S1 of some embodiments, a first temperature rise control is performed on the semiconductor heating device according to the first current temperature, the first current power, the first target temperature, and the correspondence between the theoretical power and the temperature until the first target temperature is reached, and an adjustment parameter of the first temperature rise control is calibrated. Specifically:

[0112] S11, obtaining the first current temperature Td1 and the corresponding first current power Pd1;

[0113] S12, substitute the first current temperature Td1 into the corresponding relationship between theoretical power and temperature to obtain the corresponding first current theoretical power P theory1 ;

[0114] S13, according to the first current temperature Pd1 and the first current theoretical power P theory1 The semiconductor heating device is subjected to PID temperature rise control to output a control current instruction to drive the semiconductor heating device to heat up and the adjustment parameter of the first temperature rise control is calibrated as k p 、k i and k d .

[0115] In the step of performing PID temperature-raising control on the semiconductor heating device to output a control current instruction to drive the semiconductor heating device to raise its temperature, the control current is calculated as follows:

[0116] Among them, I control To control the current, k p 、k i and k d are proportional regulation constant, integral regulation constant and differential regulation constant respectively; err(P) is the first current temperature Pd1 and the first current theoretical power P theory1 difference.

[0117] In step S2 of some embodiments: the semiconductor heating device continues to be subjected to second temperature rise control according to the second current temperature, the second current power, the second target temperature greater than the first target temperature, the adjustment parameters of the first temperature rise control and the correspondence between the theoretical power and the temperature until the second target temperature is reached.

[0118] Specifically, in step S2, the step of continuing to perform the second temperature increase control on the semiconductor heating device according to the second current temperature, the second current power, the second target temperature greater than the first target temperature, the adjustment parameter of the first temperature increase control, and the corresponding relationship equation between the theoretical power and the temperature includes:

[0119] Acquire the second current temperature and the corresponding second current power;

[0120] Obtaining a second current theoretical power according to the second current temperature and the corresponding relationship between the theoretical power and temperature;

[0121] According to the second current power, the first current theoretical power and the adjustment parameter of the first temperature rise control, k p 、k i and k d The semiconductor heating device is subjected to PID temperature increase control to output a control current instruction to drive the semiconductor heating device to increase its temperature.

[0122] More specifically, in the step of performing PID temperature rise control on the semiconductor heating device to output a control current instruction to drive the semiconductor heating device to heat up, the control current is calculated as follows:

[0123] Among them, I control To control the current, k p 、k i and k d are the proportional regulation constant, the integral regulation constant and the differential regulation constant respectively; err(P) is the difference between the second current power and the second current theoretical power.

[0124] The heating control of the present invention only requires one set of control parameters, namely the PID adjustment parameters, to control the changes in each temperature section, thereby avoiding calibration of the control parameters for different temperature sections and error reporting due to the decreasing temperature-power relationship.

[0125] In a specific embodiment of the present invention, the semiconductor heating device 1 receives a control instruction from the power control unit 2, the control instruction including information about the power difference err(P), and the semiconductor heating device 1 generates a corresponding control current I according to the control instruction. control , and the semiconductor heating device 1 is heated according to the control current.

[0126] In a specific embodiment of the present invention, the process of generating a control instruction according to the corresponding relationship between the current temperature, the target temperature, and the theoretical power and temperature is as follows:

[0127] Obtaining the theoretical power corresponding to the target temperature according to the target temperature and the corresponding relationship between the theoretical power and temperature;

[0128] Obtaining a power difference based on the theoretical power corresponding to the target temperature and the current power of the semiconductor heating device;

[0129] The power difference is processed to generate a control instruction.

[0130] In order to more clearly and obviously prove the technical effects that can be achieved by the technical solution of the present invention, the following comparative analysis is made:

[0131] The present invention provides an embodiment, which adopts a carbon fiber heating tube with a specification of "tube diameter 10mm24V200W / 210mm" as a semiconductor heating device 1 (the heating tube can be used as a heating device for heating the reaction space in the deposition reaction chamber), a K-type thermocouple nickel-chromium as a temperature measuring unit 2, and a PSU selected to be compatible with the carbon fiber heating tube and the K-type thermocouple nickel-chromium as a power control unit 4. The carbon fiber heating tube is placed in a room temperature and normal pressure environment for testing, and the temperature is increased from room temperature at a heating rate of 0.4 degrees Celsius per minute using an electric current temperature control method. 50 degrees Celsius is used as the first preset temperature, 100 degrees Celsius is used as the second preset temperature, and every 50 degrees Celsius in this sequence is used as a preset temperature until the steady-state stage at the preset temperature of 450 degrees Celsius is reached. For example, each preheating control is controlled so that each stage is heated to the overshoot temperature corresponding to each preset temperature, and then reaches the steady-state stage through balance control before continuing to heat to the next preset temperature. In the steady-state stage of each preset temperature (meeting the temperature fluctuation condition and the power fluctuation condition), the preset temperature is taken as the steady-state temperature, and the real-time steady-state power in the steady-state stage is arbitrarily selected as the steady-state power for fitting to obtain the corresponding relationship between the theoretical power and temperature. The data groups (steady-state temperature, steady-state power) used for fitting are (50, 1.3), (100, 2.1), (150, 4.6), (200, 8.6), and (250, 14), (300, 16), (350, 21), (400, 27) and (450, 33), respectively. The temperature unit is degrees Celsius and the power unit is watt. The corresponding relationship between the theoretical temperature and power obtained after fitting is as follows: P theory =4.139-0.1061T+0.001113T 2 -(2.909×10 -6 )T 3 +(2.839×10 -9 )T 4 ;

[0132] Then stop heating and wait for the heater to cool to room temperature, and then continue to increase the temperature in stages (PID control) at 0.4 degrees Celsius per minute from room temperature to execute S1 and S2. After the PID control of step S1 reaches the steady state corresponding to 150 degrees Celsius, the K of the PID control at this time is calibrated. p =1.3795, Ki =0.38, K d =0.04585, then heat up at the same rate and execute the PID control of step S2 to the steady state corresponding to 200 degrees Celsius and 250 degrees Celsius respectively, and use K p =1.3795, K i =0.38, K d =0.04585 as a constant, the temperature curve shown in Figure 5 is obtained.

[0133] The embodiment of the present invention uses the temperature-time curve obtained by traditional PID control as shown in Figure 6 to illustrate that the adjustment of each control parameter is variable. The difference from the above embodiment is that there is no step of fitting the theoretical temperature and power correspondence, and traditional PID control is used in the temperature control process. The temperature is raised from room temperature at 0.4 degrees Celsius per minute. The K value calibrated during the process of heating from room temperature to 75 degrees Celsius is p =1.7100,K i =0,K d =15, and the K value is marked during the process of continuing to heat up to 127 degrees Celsius. p =3.442, Ki=0.00125, Kd=36, and the K value is calibrated during the process of heating to 222 degrees Celsius. p =3.4424, Ki=0.005625, Kd=22.5, and the K calibrated in the process of continuing to heat up to 272 degrees Celsius p =4.9916, Ki=0.0150, Kd=15. The traditional PID control is as follows (the specific control method is a conventional technical means in this field):

[0134] It is further explained that the heating rates selected in the above embodiments and the conventional PID control example are adapted and selected according to the type of the semiconductor heating device itself.

[0135] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A temperature control method for a semiconductor heating device, characterized in that, It includes the following steps: S0: Provide the correspondence between the theoretical power and the temperature; The correspondence between the theoretical power and the temperature is obtained by preheating and controlling the semiconductor heating device with different preset temperatures as the preset target temperatures and performing fitting processing on the temperature data and power data in the steady-state stage corresponding to the different preset temperatures obtained; S1: Obtain the first current temperature and the first current power, perform the first temperature increase control on the semiconductor heating device according to the first current temperature, the first current power, the first target temperature, and the correspondence between the theoretical power and the temperature, and calibrate the adjustment parameters of the first temperature increase control; S2: Obtain the second current temperature and the second current power, and perform the second temperature increase control on the semiconductor heating device according to the second current temperature, the second current power, the second target temperature, the adjustment parameters of the first temperature increase control, and the correspondence between the theoretical power and the temperature.

2. The temperature control method according to claim 1, wherein In the step S0, the corresponding relationship between the theoretical power and the temperature is: P theory = a0 + a1T + a2T 2 + a3T 3 + a4T 4 Among them, P theory is the theoretical power, T is the temperature, and a0, a1, a2, a3, and a4 are constants.

3. The temperature control method according to claim 1, wherein In the step S0, the step of providing the correspondence between the theoretical power and the temperature includes: Perform preheating control on the semiconductor heating device with N different preset temperatures as the preset target temperatures respectively until reaching the steady-state stage corresponding to the different preset temperatures, where N is a positive integer greater than or equal to 4; Obtain the steady-state temperature and the corresponding steady-state power at each steady-state stage; Perform the fitting processing according to the obtained N groups of steady-state temperature and corresponding steady-state power data groups to obtain the correspondence between the theoretical power and the temperature.

4. The temperature control method according to claim 3, characterized in that, The preheating control includes current temperature increase control.

5. The temperature control method according to claim 3, characterized in that, In the step S0, the step of performing preheating control on the semiconductor heating device with N different preset temperatures as the preset target temperatures includes: First, perform the preheating control of the Mth stage on the semiconductor heating device with the Mth preset temperature as the preset target temperature, and judge whether the temperature fluctuation situation meets the temperature steady-state condition according to the obtained temperature information, and then judge whether the power fluctuation situation meets the power steady-state condition according to the obtained power information to reach the corresponding steady-state stage; Then perform the preheating control of the (M + 1)th stage on the semiconductor heating device with the (M + 1)th preset temperature as the preset target temperature; The (M + 1)th preset temperature is greater than the Mth preset temperature, and M is a positive integer greater than or equal to 1 and less than N.

6. The temperature control method according to claim 5, characterized in that, The difference between the (M + 1)th preset temperature and the Mth preset temperature is not less than 50 degrees Celsius and not higher than 100 degrees Celsius.

7. The temperature control method according to claim 5, wherein The step of judging whether the temperature fluctuation situation meets the temperature steady-state condition according to the obtained temperature information and then judging whether the power fluctuation situation meets the power steady-state condition according to the obtained power information includes: Obtain the real-time temperatures of the semiconductor heating device within a certain period of time starting from the t1 time node and calculate the corresponding average temperature, and judge that the differences between the real-time temperatures and the average temperature are all within the temperature fluctuation threshold range to meet the temperature steady-state condition; Obtain the real-time powers of the semiconductor heating device within consecutive time intervals starting from the time node t1, calculate the average power corresponding to each time interval, and determine whether the power fluctuation percentage between the average powers corresponding to adjacent time intervals is within the power fluctuation threshold range to meet the power steady-state condition.

8. The temperature control method according to claim 7, characterized in that, The temperature fluctuation threshold range is -0.1 °C to +0.1 °C, the certain time period is not less than 2 minutes, the time interval is not less than 120 seconds, and the power fluctuation threshold range is -10% to +10%.

9. The temperature control method according to claim 3, wherein The steps of obtaining the steady-state temperature and the corresponding steady-state power in each of the steady-state stages include: Obtain the real-time steady-state temperatures within the selected time period in the steady-state stage corresponding to the preset temperature, or obtain the real-time steady-state temperatures within the selected time period and calculate the corresponding average steady-state temperature; Select either the average steady-state temperature or any one of the real-time steady-state temperatures as the steady-state temperature.

10. The temperature control method according to claim 3, wherein The steps of obtaining the steady-state temperature and the corresponding steady-state power in each of the steady-state stages include: Select the preset temperature as the steady-state temperature.

11. The temperature control method according to claim 3, wherein The steps of obtaining the steady-state temperature and the corresponding steady-state power in each of the steady-state stages include: Obtain the real-time steady-state powers within the selected time period in the steady-state stage corresponding to the preset temperature, or obtain the real-time steady-state powers within the selected time period and calculate the corresponding average steady-state power; Select either the average steady-state power or any one of the real-time steady-state powers as the steady-state power.

12. The temperature control method according to claim 3, characterized in that, At least one of the different preset temperatures is higher than the first target temperature.

13. The temperature control method according to claim 1, characterized in that, In the step S1, the step of performing the first temperature increase control on the semiconductor heating device according to the first current temperature, the first current power, the first target temperature, and the corresponding relationship between the theoretical power and the temperature includes: Obtain the first current theoretical power according to the first current temperature and the corresponding relationship between the theoretical power and the temperature; Perform PID temperature increase control on the semiconductor heating device according to the first current power and the first current theoretical power to output a first control current command to drive the semiconductor heating device to increase in temperature, and calibrate the adjustment parameters of the first temperature increase control as k p , k i and k d .

14. The temperature control method according to claim 13, characterized in that, In the step S2, the step of continuing to perform the second temperature increase control on the semiconductor heating device according to the second current temperature, the second current power, the second target temperature, the adjustment parameter of the first temperature increase control, and the corresponding relationship equation between the theoretical power and the temperature includes: Obtain the second current theoretical power according to the second current temperature and the corresponding relationship between the theoretical power and the temperature; Based on the second current power, the first current theoretical power, and k p , k i , and k d perform PID temperature increase control on the semiconductor heating device to output a second control current command to drive the semiconductor heating device to increase temperature.

15. The temperature control method according to claim 14, characterized in that, In the steps S1 and S2, the steps of performing the PID temperature increase control on the semiconductor heating device both include calculating a control current according to the following formula: Among them, I control is the control current, k p , k i and k d are the proportional adjustment constant, the integral adjustment constant, and the differential adjustment constant, respectively; In the step S1, err(P) is the difference between the first current power and the first current theoretical power; In the step S2, err(P) is the difference between the second current power and the second current theoretical power.

16. A temperature control system, characterized in that, Include: A semiconductor heating device that performs temperature increase in response to the drive of a power control unit; A temperature measurement unit that obtains and transmits the current temperature of the semiconductor heating device; The power control unit drives the semiconductor heating device in response to a control instruction, and interacts with the main control unit to transmit the current power at the current temperature. The main control unit interacts with the temperature measurement unit and the power control unit. The main control unit generates a control instruction according to the current temperature, the current power, the target temperature, and the corresponding relationship between the theoretical power and the temperature, and transmits the control instruction to the power control unit; Among them, when performing heating control based on the control instruction, the adjustment parameters of the heating control are calibrated, and the subsequent heating control in different stages is executed with the calibrated adjustment parameters.

Images