Capacitance film vacuum gauge temperature control method based on time delay effect

Abstract

The invention relates to a capacitance thin film vacuum gauge temperature control method based on a time delay effect, which comprises the following steps: multiple time slice data of target equipment are acquired, each time slice comprises the temperature T and the power p at the moment, and an acquired data set is divided into a solution set and a verification set; establishing a time delay conversion model, quantifying a delay effect of power conversion as ts time slices, defining a conversion coefficient # imgabs0 #, and setting temperature constant power x and the time slices ts as function hyper-parameters; the AI algorithm and the solution set are utilized to obtain a conversion coefficient # imgabs1 # hyper-parameter x, ts and a conversion coefficient # imgabs2 # obtained through solution, verification is carried out on a verification set to obtain an actual temperature difference, and the predicted temperature difference and the actual temperature difference serve as evaluation indexes; taking the actual temperature difference closest to the predicted temperature difference as a preference, and performing PID control on the capacitance film vacuum gauge according to each parameter of the obtained actual temperature difference; the difference between the set temperature and the actual temperature is reduced, and the temperature fluctuation of each product can be controlled within + / -0.01 DEG C through the optimization algorithm.

Description

Technical Field

[0001] The invention relates to the technical field of capacitance film vacuum gauges, and in particular to a temperature control method of a capacitance film vacuum gauge based on a time delay effect. Background Art

[0002] At present, capacitance thin film vacuum gauges are used in a variety of occasions. For example, in semiconductor manufacturing processes, processes such as dry etching and physical vapor deposition usually require the use of one or more high-precision vacuum gauges. The main high-precision vacuum gauge currently used is the capacitance thin film vacuum gauge. Its measurement principle is that gas is introduced into the detection chamber through an inlet pipe. Due to the effect of gas pressure, the detection diaphragm is deformed, resulting in a change in the distance between the detection diaphragm and the fixed plate, which in turn causes a change in the capacitance between the two. Subsequently, the capacitance is measured using electrical methods, and the corresponding pressure value can be obtained based on the correspondence between the capacitance change value and the gas pressure.

[0003] Current temperature control technology typically uses a PID algorithm, with fixed PID parameters input based on expert historical experience to achieve constant temperature. However, due to the inherent delay between temperature measurement and the heating unit—that is, the difference in transmission time between temperature measurement and heating control and heat conduction—and the fact that heat conduction varies between different products, and even between different devices for the same product, there is inevitably a certain difference between the actual temperature and the set temperature. These factors combine to make it difficult, even with advanced temperature control technology, to completely eliminate the impact of temperature fluctuations on measurement accuracy.

[0004] Therefore, it is necessary to develop a capacitance thin film vacuum gauge temperature control method based on the time delay effect to solve the above problems. Summary of the Invention

[0005] The object of the present invention is to provide a temperature control method for a capacitance film vacuum gauge based on a time delay effect and capable of reducing temperature fluctuations.

[0006] To achieve the above object, the present invention provides the following technical solution: a temperature control method for a capacitance film vacuum gauge based on a time delay effect, comprising the following steps:

[0007] Step 1: Collect multiple time slice data of the target device. Each time slice contains the temperature T and power p at that moment. The collected data set is divided into a solution set and a verification set.

[0008] Step 2: Establish a delay conversion model:

[0009]

[0010] The delay effect of quantizing power conversion is t s Time slice, and define the conversion factor The conversion coefficient k represents the power complete conversion coefficient, the conversion coefficient Indicates that after t s Power conversion factor of time slice;

[0011] Step 3: Set the temperature constant power x and time slice t s As a function hyperparameter;

[0012] Step 4: Use the existing AI algorithm and solution set to solve the multivariate linear equation and obtain the conversion coefficient

[0013] Step 5: Hyperparameters x, t s And the conversion coefficient obtained Verify on the validation set to obtain the actual temperature difference, and use the predicted temperature difference and the actual temperature difference as evaluation indicators;

[0014] Step 6: Take the actual temperature difference closest to the predicted temperature difference as the preferred one, and obtain the conversion coefficient of the actual temperature difference Constant power x and time slice t s , perform PID control on the capacitance film vacuum gauge.

[0015] Furthermore, in the time delay conversion model, the conversion coefficient The following relationship is satisfied:

[0016]

[0017] Furthermore, the power to maintain constant temperature z The value range is 55000 to 57000.

[0018] Furthermore, the delay time slice t s The value range is 5 to 30.

[0019] Furthermore, in the delay conversion model, the corresponding formula for power and temperature change is:

[0020]

[0021] Where k is the conversion coefficient, p is the current power, x is the power required to maintain a constant temperature, and the noise impact follows a normal distribution with a mean of zero.

[0022] Further, beyond t s There is no residual energy in the time slice power, which has been fully converted into temperature.

[0023] Furthermore, the implementation of the PID control includes: obtaining the difference between the current temperature and the preset temperature through the temperature measuring unit, and using the conversion coefficient of the device Constant power x and time slice ts Calculate the actual required power p and convert the power p into Proportional, integral, and derivative parameters of control.

[0024] Further, t s The energy converted into temperature and heat in a time slice is expressed as follows:

[0025]

[0026] Furthermore, the residual energy is expressed as follows:

[0027]

[0028] in is the conversion coefficient, and the remaining energy will be used to maintain the temperature after time t.

[0029] Compared with the prior art, the beneficial effects of the present invention are: an AI temperature control method for a capacitance film vacuum gauge of the present invention has the characteristic of reducing the difference between the set temperature and the actual temperature. In actual use, each product is subjected to a separate heating process during the manufacturing process. Based on the above algorithm, unique temperature control parameters are calculated for each product. These parameters are then applied to the temperature control unit of the corresponding product to reduce the difference between the set temperature and the actual temperature. Through this optimization algorithm, the temperature fluctuation of each product can be controlled within ±0.01°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0031] Figure 1 The present invention is a flow chart of a temperature control method of a capacitance thin film vacuum gauge based on a time delay effect. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] The present invention is a temperature control method for a capacitance film vacuum gauge based on a time delay effect.

[0034] When the equipment uses PID regulation, it is adjusted by setting fixed parameters P (Kp), I (Ti), and D (Td). This will allow the heating system to always generate a constant power p for heating. The PID algorithm is usually executed by a PID controller (proportional-integral-differential controller), which consists of a proportional unit, an integral unit, and a differential unit.

[0035] Specific parameters: power is p, complete conversion coefficient is k (with delay), power to maintain constant temperature is x, temperature change is

[0036] Other noises follow a normal distribution. The mean value during the time is 0, which can be offset and ignored, and the corresponding formula for power and temperature changes over a long period of time is obtained:

[0037]

[0038] Since the conversion of power to temperature has a time delay, t S The power conversion coefficient after time is Beyond t S There is no residual energy in the power of the time slice, and it has all been converted into temperature. For a certain time t, the temperature is T, and the previous t S The energy converted into temperature and heat in a time slice is expressed as follows:

[0039]

[0040] The residual energy is expressed as follows:

[0041]

[0042] in is the conversion coefficient, and the remaining energy will be used to maintain the temperature after time t.

[0043] Assume that the temperature of a device at time t1 is T1, the temperature at time t2 is T2, and t2 = t1 + t s The residual energy at time t1 is expressed as:

[0044]

[0045] The energy converted into temperature and heat from time t1 to time t2 is expressed as:

[0046]

[0047] These two energies work together and are converted into temperature, causing the temperature to rise from T_1 to T_2, so we can get:

[0048]

[0049] Based on the above formula, for a specific device, multiple sets of data are collected, including parameters such as t1, t2, T2, T1 and power p at a specific time. The data set is divided into a solution set and a verification set. The temperature is maintained constant power x and time slice t S As a function hyperparameter, it needs to satisfy the relationship

[0050] Using the existing AI algorithm and solution set, solve the multivariate linear equation and obtain the conversion coefficient. S The conversion coefficient obtained is verified on the validation set, and the predicted temperature difference and the actual temperature difference are used as evaluation indicators to determine a set of customized parameters for the device, including the conversion coefficient, the power x to maintain constant temperature, and the time slice t S .

[0051] In actual use, the temperature measurement unit obtains the current temperature. The difference between the current temperature and the preset temperature is the temperature difference. The customized parameters of the device are substituted into the formula to solve the actual required power p, which is then converted into the three parameters in PID control for PID control.

[0052] The present invention provides an AI temperature control method for capacitance film vacuum gauges, which reduces the difference between the set temperature and the actual temperature. In actual use, each product undergoes a separate heating process during the manufacturing process. Based on the above algorithm, unique temperature control parameters are calculated for each product. These parameters are then applied to the temperature control unit of the corresponding product to reduce the difference between the set temperature and the actual temperature. Through this optimization algorithm, the temperature fluctuation of each product can be controlled within ±0.01°C.

[0053] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A temperature control method for a capacitance thin film vacuum gauge based on a time delay effect, characterized in that: The following steps are involved: Step 1: Collect multiple time slice data of the target device. Each time slice contains the temperature T and power p at that moment. The collected data set is divided into a solution set and a verification set. Step 2: Establish a delay conversion model: The delay effect of quantizing power conversion is t s Time slice, and define the conversion factor The conversion coefficient k represents the power complete conversion coefficient, the conversion coefficient Indicates that after t s Power conversion factor of time slice; Step 3: Set the temperature constant power x and time slice t s As a function hyperparameter; Step 4: Use the existing AI algorithm and solution set to solve the multivariate linear equation and obtain the conversion coefficient Step 5: Hyperparameters x, t s And the conversion coefficient obtained Verify on the validation set to obtain the actual temperature difference, and use the predicted temperature difference and the actual temperature difference as evaluation indicators; Step 6: Take the actual temperature difference closest to the predicted temperature difference as the preferred one, and obtain the conversion coefficient of the actual temperature difference Constant power x and time slice t s , perform PID control on the capacitance film vacuum gauge.

2. The temperature control method of a capacitance film vacuum gauge based on time delay effect according to claim 1, characterized in that: In the time delay conversion model, the conversion coefficient The following relationship is satisfied:

3. The temperature control method of a capacitance film vacuum gauge based on time delay effect according to claim 1, characterized in that: The power x for maintaining constant temperature ranges from 55,000 to 57,000.

4. The temperature control method of a capacitance film vacuum gauge based on time delay effect according to claim 1, characterized in that: The delay time slice t s The value range is 5 to 30.

5. The temperature control method of a capacitance film vacuum gauge based on time delay effect according to claim 1, characterized in that: In the delay conversion model, the corresponding formula for power and temperature change is: Where k is the conversion coefficient, p is the current power, x is the power required to maintain a constant temperature, and the noise impact follows a normal distribution with a mean of zero.

6. The temperature control method of a capacitance film vacuum gauge based on time delay effect according to claim 5, characterized in that: Beyond t s There is no residual energy in the time slice power, which has been fully converted into temperature.

7. The temperature control method of a capacitance film vacuum gauge based on time delay effect according to claim 1, characterized in that: The implementation of the PID control includes: obtaining the difference between the current temperature and the preset temperature through the temperature measuring unit, using the conversion coefficient of the device Constant power x and time slice t s Calculate the actual required power p and convert the power p into Proportional, integral, and derivative parameters of control.

8. The temperature control method of a capacitance film vacuum gauge based on time delay effect according to claim 1, characterized in that: t s The energy converted into temperature and heat in a time slice is expressed as follows:

9. The temperature control method of a capacitance film vacuum gauge based on time delay effect according to claim 8, characterized in that: The residual energy is expressed as follows: in is the conversion coefficient, and the remaining energy will be used to maintain the temperature after time t.

Images