JP2021064068A - Valve control device and estimation device - Google Patents

Abstract

To provide a valve control device capable of improving accuracy of pressure adjustment control.SOLUTION: In a valve control device 1b, a calculation unit 210 fixes opening θr of a valve element 12 to be constant at the time of gas introduction into a chamber, and estimates exhaust information of a vacuum valve 1 based on change information of a pressure measurement value Pr when the opening θr of the valve element 12 is fixed to be constant. A pressure adjustment control unit 21 controls the opening of the valve element 12 based on the exhaust information, and performs pressure adjustment control of the chamber.SELECTED DRAWING: Figure 2

Description

The present invention relates to a valve control device and an estimation device.

In a semiconductor process such as dry etching, conditions such as gas type and flow rate Qin are predetermined for the process gas introduced into the chamber, and the flow rate controller adjusts the conditions so as to meet the conditions. The chamber pressure Pr is one of the important process conditions, and the chamber pressure Pr is maintained at a predetermined pressure value by controlling the valve body opening position of the valve so as to have a predetermined predetermined pressure value. .. As such a valve, an automatic pressure adjusting valve (also referred to as an APC valve) that drives and controls the valve body with a motor like the valve described in Patent Document 1 is used.

JP-A-2018-106718

In the valve described in Patent Document 1, the pressure adjusting operation is performed based on the effective exhaust speed data stored in advance. However, the gas type actually flowed is not always the same as the gas type of the data stored in advance, and there is a problem that the accuracy of the pressure regulation control is lowered when the gas type is different.

The valve control device according to the first aspect of the present invention controls the valve body opening degree based on the pressure measurement value of the chamber equipped with the vacuum valve and the pressure target value of the chamber, and adjusts the pressure of the chamber. In the valve control device, the opening setting unit that fixes the valve body opening constant when gas is introduced into the chamber and the change information of the pressure measurement value when the valve body opening is fixed constant. Based on this, an estimation unit that estimates the exhaust information of the vacuum valve is provided, the valve body opening degree is controlled based on the exhaust information, and the pressure adjustment control of the chamber is performed.
The estimation device according to the second aspect of the present invention is an estimation device that estimates the exhaust information of the vacuum valve mounted on the chamber, and is a pressure measurement value of the chamber when the valve body opening degree of the vacuum valve is constant. At least one of the valve exhaust speed, the flow rate of the gas introduced into the chamber, and the gas type information of the gas is estimated as the exhaust information based on the change information of the above.

According to the present invention, the accuracy of pressure regulation control can be improved.

FIG. 1 is a block diagram showing a schematic configuration of a vacuum valve mounted on a vacuum processing apparatus. FIG. 2 is a functional block diagram of the vacuum valve 1. FIG. 3 is a diagram illustrating a pressure regulation logic in open control. FIG. 4 is a diagram showing a transition of states (θr, Pr) by open control. FIG. 5 is a diagram showing an opening degree transition graph and a pressure transition graph. FIG. 6 is a diagram showing the relationship between the gas type and the effective exhaust speed. FIG. 7 is a diagram showing a pressure transition when different gas types are used. FIG. 8 is a diagram showing a locus when the value of the stored effective exhaust speed deviates from the effective exhaust speed of the gas actually flowing. FIG. 9 is a diagram showing a calculation example of the effective exhaust speed ratio when the reliability is sufficiently ensured. FIG. 10 is a diagram showing an example of calculating the effective exhaust speed ratio when the reliability is insufficient. FIG. 11 is a diagram showing an example of application of the effective exhaust speed ratio to pressure regulation control, and shows a case where the effective exhaust speed of the gas actually flowing is smaller than the stored effective exhaust speed. FIG. 12 is a diagram showing an example of application of the effective exhaust speed ratio to pressure regulation control, and shows a case where the effective exhaust speed of the gas actually flowing is larger than the stored effective exhaust speed. FIG. 13 is a flowchart showing a series of processes in the calibration mode. FIG. 14 is a flowchart showing a process following the process of FIG. FIG. 15 is a diagram showing an opening degree measurement value θr (line L31) and a pressure measurement value Pr (line L32) at the time of calibration processing.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a vacuum valve 1 mounted on a vacuum processing apparatus. The vacuum valve 1 is a valve for pressure regulation, and includes a valve body 1a provided with a valve body 12 and a valve control device 1b for controlling opening / closing drive of the valve body 12. The valve body 1a is mounted in the vacuum chamber 3 of the vacuum processing device, and the vacuum pump 4 is mounted on the exhaust side of the valve body 1a. A gas such as a process gas is introduced into the vacuum chamber 3 via the flow rate controller 32. The flow rate controller 32 is a device that controls the flow rate Qin of the gas introduced into the vacuum chamber 3, and is controlled by the main controller MC of the vacuum processing device. The pressure in the vacuum chamber 3 (chamber pressure) is measured by the vacuum gauge 31, and the pressure measurement value Pr is input to the valve control device 1b.

The valve body 1a is provided with a motor 13 for opening and closing the valve body 12. The valve body 12 is opened and closed by the motor 13. The motor 13 is provided with an encoder 130 for detecting the opening / closing angle of the valve body 12. The detection signal of the encoder 130 is input to the valve control device 1b as an opening degree signal θr of the valve body 12 (hereinafter, referred to as an opening degree measurement value θr).

The valve control device 1b that controls the valve body 1a includes a pressure adjusting control unit 21 and a motor drive unit 22. In addition to the pressure measurement value Pr and the opening degree measurement value θr described above, the pressure target value Ps of the vacuum chamber 3 is input to the valve control device 1b from the main controller MC of the vacuum processing device described above. The motor drive unit 22 includes an inverter circuit for driving the motor and a motor control unit that controls the motor, and the opening degree measurement value θr from the encoder 130 is input. The chamber pressure Pr measured by the vacuum gauge 31 is input to the pressure adjusting control unit 21, and the pressure target value Ps of the vacuum chamber 3 is input from the main controller MC of the vacuum processing device described above. On the other hand, the determination result D, which will be described later, is transmitted from the pressure regulation control unit 21 to the main controller MC.

The valve control device 1b includes, for example, an arithmetic processing device such as a microcomputer having a CPU, a memory (ROM, RAM), a peripheral circuit, and the like, and a pressure adjustment control unit 21 and a motor drive unit are provided by a software program stored in the ROM. The functions of the 22 motor control units are realized. Further, instead of the microcomputer, it may be configured by a digital arithmetic unit such as FPGA (Field Programmable Gate Array) and its peripheral circuit.

FIG. 2 is a functional block diagram of the vacuum valve 1. The pressure adjusting control unit 21 includes a calculation unit 210, a feedforward controller 220, a feedback controller 230, and a storage unit 240. The storage unit 240 stores parameters required for pressure regulation control (for example, data related to the effective exhaust speed Se and the like described later). The opening degree measurement value θr detected by the encoder 130 is input to the motor drive unit 22 and the calculation unit 210.

Also in the present embodiment, as in the invention of Patent Document 1 described above, rough adjustment is performed by open control up to the vicinity of the pressure target value, and further, the control is switched to close control and fine adjustment is performed to reach the pressure target value. In the pressure regulation control unit 21, the calculation unit 210 and the feedforward controller 220 correspond to the open control unit, and the subtractor 229 and the feedback controller 230 that generate the deviation ε (= Pr-Ps) correspond to the close control unit. ..

The pressure measurement value Pr, the pressure target value Ps, and the opening degree measurement value θr are input to the calculation unit 210. The calculation unit 210 calculates the target opening degree estimated value θse, the predicted pressure Pp, and the exhaust information (details will be described later) of the valve body 1a based on the pressure measured value Pr, the pressure target value Ps, and the opening degree measured value θr. To do. Generally, even if the valve body opening is fixed at a constant value, it takes a certain amount of time for the chamber pressure to reach the pressure equilibrium value corresponding to the valve body opening. The predicted pressure Pp is an estimated pressure value after Δt seconds have elapsed from the time when the measured pressure value Pr is measured (for example, a time longer than the control cycle such as t = 0.4 seconds). The method of obtaining the predicted pressure Pp will be described later.

The feedforward controller 220 outputs the opening degree setting θ1 based on the target opening degree estimated value θse. Further, the feedback controller 230 outputs the opening degree setting θ2 based on the deviation ε = Pr−Ps. The output opening degree setting θ1 and opening degree setting θ2 are added by the adder 225, and the addition result is input to the motor drive unit 22 as the opening degree setting θset. The motor drive unit 22 drives the motor 13 based on the opening degree setting θset and the opening degree measurement value θr input from the encoder 130.

When the measured opening value θr finally becomes the estimated target opening degree θse by the open control, the opening degree setting θ1 output from the feedforward controller 220 in FIG. 2 remains fixed at that value and is closed from the open control. Switch to control. When the control is switched to the close control, the pressure target value Ps is input to the subtractor 229 in FIG. 2, and the feedback controller 230 outputs the opening degree setting θ2 based on the deviation ε = Pr−Ps. Usually, the feedback controller 230 is composed of a proportional gain and an integrated gain (so-called PI gain). The motor drive unit 22 controls the opening degree based on the opening degree setting θset = θ1 (fixed) + θ2. The opening measurement value θr is θr = θ1 + θ2 unless the valve body 12 is moving at high speed.

Until the start of the close control, the subtractor 229 is configured to input the pressure measurement value Pr instead of the pressure target value Ps. Therefore, at the time of open control, the pressure deviation ε = 0 is input to the feedback controller 230, and the opening degree setting θ2 = 0 is output from the feedback controller 230.

(How to find the predicted pressure Pp)
As an example of how to obtain the predicted pressure Pp, there is a method as described in paragraph 0024 of JP-A-2018-106718. Here, only the main points will be described. Regarding the pressure measurement value Pr of the vacuum chamber 3, the exhaust equation represented by the following equation (1) is established.
V × (dPr / dt) + Se × Pr = Qin… (1)
In the formula (1), V is the chamber volume including the vacuum chamber 3, Se is the effective exhaust velocity of the exhaust system including the conductance of the vacuum valve 1, and Qin is the flow rate of the gas introduced into the vacuum chamber 3. The information of the effective exhaust speed Se is given as the correlation Se (θ) between the opening degree θ of the vacuum valve 1 and the effective exhaust speed Se.

…（２） In the pressure regulation control, the effective exhaust speed Se estimated based on the equation (1) is used. Further, the above-mentioned exhaust equation (1) is used for calculating the predicted pressure. The general solution of equation (1) is expressed as the following equation (2).

… (2)

As a method of calculating the predicted pressure Pp after t seconds from the present as the base point by the equation (2), for example, the discretization relational equations (3) and (4) as shown below are used. Using the equations (3) and (4), the recurrence formula in Δt increments up to t seconds ahead from the present is obtained, and the predicted pressure Pp t seconds ahead is obtained. For example, if k = 1 to 99 and t seconds ahead is 0.4 seconds, then Δt = 4 msec.
P (Δt destination) = Cp (current) × P (current)
＋ Cq (current) × {Qin (current) ＋ A × Δt}… (3)
P ((k + 1) × Δt) = Cp (k) × P (k × Δt)
＋ Cq (k) × {Qin (current) ＋ A × k × Δt}… (4)
However,
Cp (k) = exp {(−Se (k × Δt) / V) × Δt}
Cq (k) = (1 / V) × {1 / (−Se (k × Δt) / V)} × (Cp (k) -1)
In order to calculate the predicted pressure Pp t seconds ahead using equations (3) and (4), the flow rate estimate from the present to t seconds later and the effective exhaust velocity Se from the present to t seconds later are required. Is. For example, in equation (4), {Qin (current) + A × k × Δt} represents the estimated flow rate after k × Δt seconds from the present, and here, the flow rate changes as A × k × Δt. Assuming a case, A is a constant.

The determination using the predicted pressure Pp is performed according to the pressure adjusting logic shown in FIG. The coordinate system shown in FIG. 3 is a θr-Pr coordinate system having a state (θr, Pr) as a coordinate point, and the origin represents a state (θse, Ps). θse and Ps are the above-mentioned target opening degree estimation value and pressure target value. In such a θr-Pr coordinate system, the valve body 12 is based on which of the first to fourth quadrants the state (θr, Pr) is in, and the magnitude relationship between the predicted pressure Pp and the pressure target value Ps. It is determined whether the opening degree θ is controlled in the opening direction or the closing direction.

When the states (θr, Pr) before the opening change are in the second quadrant and the fourth quadrant, the opening θ is adjusted in the direction of the target opening estimated value θse. As a result, the measured pressure value Pr changes in the direction of the pressure target value Ps. That is, in the case of the second quadrant, the pressure decreases, and in the case of the fourth quadrant, the pressure increases. The starting point of the control start is either the 2nd or 4th quadrant, the 4th quadrant in the case of the up case where the pressure rises from the starting pressure Pstt, and the 1st in the case of the down case where the pressure drops from the starting pressure Pstt. There are two quadrants.

On the other hand, when the states (θr, Pr) before the opening change are in the first quadrant and the third quadrant, the opening adjustment direction is set according to the magnitude relationship between the predicted pressure Pp and the pressure target value Ps. .. In the first quadrant, when the predicted pressure Pp is larger than the pressure target value Ps such as Pp> Ps, the opening is adjusted in the direction of increasing the opening and lowering the chamber pressure (the direction indicated by the arrow pointing to the right). This is done, or the opening value is maintained as it is as indicated by the circle 50. On the contrary, when Pp ≦ Ps, the opening degree is adjusted in the direction in which the opening degree is reduced and the chamber pressure is increased (the direction indicated by the arrow pointing to the left). In the third quadrant, when Pp> Ps, the opening degree is adjusted in the direction of increasing the opening degree and lowering the chamber pressure (the direction indicated by the arrow pointing to the right). On the contrary, when Pp ≤ Ps, the opening is adjusted in the direction of reducing the opening and increasing the chamber pressure (the direction indicated by the arrow pointing to the left), or the opening value is set as shown by the circle 50. Keep it as it is.

(Control example of open control)
The change of the state (θr, Pr) in the open control will be described with reference to FIGS. 4 and 5. FIG. 4 shows an example of the transition of the state (θr, Pr) by the open control when the state (θstt, Pstt) of the starting point of the control start is in the fourth quadrant as in the point B1. The state at the point B2 is represented by (θse0, Pra), and the state at the point B3 is represented by (θse0, Prb). The upper graph of FIG. 5 is a pressure transition graph showing the relationship between the measured pressure value Pr (solid line) and the predicted pressure Pp (broken line), with the vertical axis representing the pressure P and the horizontal axis representing the time t. The lower graph of FIG. 5 is an opening degree transition graph showing a time change of the opening degree measurement value θr, where the vertical axis represents the opening degree θ and the horizontal axis represents the time t.

As shown in the opening degree transition graph of FIG. 5, when the opening degree is changed from the opening degree θstt of the point B1 to the opening degree θse0 of the point B2 by the open control, the pressure measurement value starts to increase from Pstt at the point B1. .. After changing the opening, the opening is temporarily fixed at θ = θse0. The pressure transition graph of FIG. 5 shows the pressure transition after t = t0 when the opening degree θ is changed to θse0 (time t0) and then the state of θ = θse0 is continued. When the opening degree is changed from θstt to θse0, the pressure measurement value Pr starts to rise from Pstt like the line L1A.

When a sufficient time elapses, the measured pressure value Pr converges to the pressure equilibrium value (pressure value in the equilibrium state) Pe (θse0) at the opening degree θse0. The opening degree θse0 is set smaller than the target opening degree θs corresponding to the pressure target value Ps, and the pressure equilibrium value Pe (θse0) at which the line L1A converges is higher than the pressure target value Ps.

As described above, the line L1A in the pressure transition graph of FIG. 5 shows the transition of the pressure measurement value Pr after the opening degree is fixed to θse0 at t = t0. The line L1B shows the predicted pressure Pp with respect to the line L1A. The predicted pressure Pp is a pressure predicted value after Δt seconds (for example, 0.4 seconds) have elapsed from the time when the pressure measured value Pr is measured, and it is assumed that the pressure measured value Pr after Δt seconds is accurately predicted. In this case, the line L1B is the line L1A shifted by −Δt. When the line L1A converges to the pressure equilibrium value Pe (θse0), the line L1B of the predicted pressure Pp also converges to Pe (θse0).

Point B2 (θse0, Pra) in FIG. 4 indicates a time point when the opening degree rises to P = Pra immediately after fixing the opening degree to θse0. Looking at the line L1B of the predicted pressure Pp in the pressure transition graph of FIG. 5, the predicted pressure Ppa at t = ta is Ppa ≦ Ps, and the opening degree of the valve body 12 is the opening of the position of the point B2 according to the logic of FIG. It is maintained every time. In the third quadrant of FIG. 3, when Pp ≦ Ps, the opening is adjusted in the direction of reducing the opening (the direction indicated by the arrow pointing to the left), or the opening value is maintained as it is. However, since θse0 <θs is set, the opening degree θse0 is treated as the lower limit value of the opening degree control, and “maintaining the opening degree value as it is” is adopted as the logic when Pp ≦ Ps.

When θ = θse0 is maintained and the pressure measurement value Pr further rises, the locus indicating the state (θr, Pr) moves upward from the point B2 and reaches the point B3 at t = tb where Pr = Prb. As the line L1A rises, the line L1B of the predicted pressure Pp also rises, and when the pressure measured value Pr reaches the pressure force measured value Prb at the point B3, the predicted pressure Pp becomes Pp> Ps. As a result, the opening degree θ is changed in the direction in which the value increases according to the logic of FIG. 3, and the locus of the state (θr, Pr) moves from the point B3 to the point B4 in the vicinity of the target opening degree estimated value θse.

As described above, the predicted pressure Pp is calculated based on the exhaust characteristic data stored in the storage unit 240. This exhaust characteristic data includes valve conductance data related to a standard gas such as argon gas stored in the storage unit 240 in advance, and a calibration gas flowing in a state where the vacuum valve 1 is attached to the user's vacuum device as shown in FIG. This is the initial calibration data related to the effective exhaust speed obtained in the above. However, the gas type of the gas introduced into the vacuum chamber 3 is not always the same as the gas type of the exhaust characteristic data stored in the storage unit 240. If the gas type is different, the calculation result of the predicted pressure Pp based on the equation (2) is different, which adversely affects the open control based on the logic of FIG.

Further, the pressure regulation control is performed based on the exhaust formula of the formula (1), and the exhaust formula (1) includes the effective exhaust speed Se, which is one of the exhaust characteristic data. Therefore, if the gas type of the effective exhaust speed Se stored in the storage unit 240 is different from the gas type actually flowing, the accuracy of the pressure regulation control is lowered.

(Relationship between gas type and predicted pressure Pp)
As described above, the effective exhaust speed of the exhaust system including the conductance of the vacuum valve 1 is given as the correlation Se (θ) between the opening degree θ of the vacuum valve 1 and the effective exhaust speed Se. FIG. 6 is a diagram showing the relationship between the gas type and the effective exhaust speed, in which the vertical axis represents the effective exhaust speed Se and the horizontal axis represents the opening degree θ. Line L11 shows the effective exhaust rate Se (θ) of argon gas, line L12 shows the effective exhaust rate Se (θ) of helium gas, and line L13 shows the effective exhaust rate Se (θ) of xenon gas. Shown. The effective exhaust speed Se (θ) changes according to the opening degree θ, but the magnitude relationship of the effective exhaust gas speed Se (θ) depending on the gas type is L12>L11> L13 regardless of the opening degree θ.

Generally, the effective exhaust speed Se (θ) of the exhaust system is substantially determined by the exhaust speed Sp of the vacuum pump 4, the valve conductance C (θ) of the vacuum valve 1, and the structure of the vacuum chamber 3 for each gas type. The effective exhaust speed Se (θ) is dominated by the valve conductance C of the vacuum valve 1 except in the region where the opening degree θ is large, and in the low opening degree region θ = 0% to about 20% where pressure regulation control is performed. It is almost determined by the valve conductance C (θ). The effective exhaust gas speed Se depends not only on the opening degree θ but also on the gas flow rate Qin, but the influence of the gas flow rate Qin is smaller than the opening degree θ. Therefore, in the description in the present embodiment, the effective exhaust gas speed Se is open. It will be treated as a function of only degree θ.

FIG. 7 shows the pressure transition when the gas flow rate Qin is constant and the gas type is different. The line L1A is the same as the line L1A shown in FIG. 5, and the effective exhaust speed in that case is Se1. The effective exhaust gas velocity Se2 of the line L2A satisfies Se2> Se1, and the effective exhaust gas velocity Se3 of the line L3A satisfies Se1> Se3. The pressure equilibrium value Pe2 (θse0) of the line L2A of the effective exhaust velocity Se2 (> Se1) is lower than the pressure equilibrium value Pe (θse0) of the line L1A, and conversely, the pressure of the line L3A of the effective exhaust velocity Se3 (<Se1). The equilibrium value Pe3 (θse0) is higher than the pressure equilibrium value Pe (θse0). The line L1B shown by the broken line represents the predicted pressure Pp of the line L1A.

Here, consider a case where the effective exhaust speed of the gas actually flowing is Se1 and the effective exhaust speed stored in the storage unit 240 is Se2. The measured pressure value at t = t10 is Pr0. Since the effective exhaust velocity for the gas actually flowing is Se1, the predicted pressure in that case should be predicted based on the line L1B indicating the predicted pressure of the line L1A.

However, the effective exhaust speed stored in the storage unit 240 is Se2, and the predicted pressure estimated and calculated based on Se2 is lower than the line LIB indicating the original predicted pressure based on Se1, and Pr4 at t = t10. It becomes. That is, if the effective exhaust gas speed Se2 stored in the storage unit 240 has an error such as Se2> Se1 with respect to the effective exhaust gas speed Se1 of the gas actually flowing, the prediction of the pressure measurement value Pr with respect to the line L1A. The pressure line becomes like the line L1C below the line L1B. On the contrary, when the effective exhaust velocity Se3 (<Se1) is stored in the storage unit 240, the predicted pressure of the pressure measurement value with respect to the line L1A becomes like the line L1D above the line L1B.

In FIG. 7, the timing at which the lines L1B, L1C, and L1D exceed the pressure target value Ps is compared with the timing at which the pressure measurement value Pr indicated by the line L1A is Pr> Ps. The timing at which the predicted pressure indicated by the line L1B exceeds the pressure target value Ps is Δt seconds before the timing at which Pr> Ps. On the other hand, assuming that the timing at which the lines L1C and L1D exceed the pressure target value Ps is Δt1 second before and Δt2 seconds before, respectively, it can be seen from FIG. 7 that Δt1 <Δt <Δt2. When the line L1C is used, the prediction time is shorter than Δt, and the prediction timing is delayed as compared with the case of the line L1B. On the contrary, when the line L1D is used, the prediction time becomes longer than Δt, and the timing when Pr> Ps can be predicted earlier than the case of the line L1B can be predicted.

In this way, when the value of the effective exhaust speed stored in the storage unit 240 deviates from the effective exhaust speed of the gas actually flowing, the locus of the state (θr, Pr) shown in FIG. 4 is , The locus changes as shown in FIG. The locus shown by the broken line is the case where the effective exhaust speed Se2 (> Se1) is stored in the storage unit 240, and the timing when the predicted pressure Pp exceeds the target pressure value Ps, that is, the timing when the opening degree θ is reversed in the increasing direction. Is later than in the case of Se1. Therefore, there is a high possibility of overshooting to a pressure larger than the pressure target value Ps. On the contrary, when the effective exhaust velocity Se3 (<Se1) is stored in the storage unit 240, the timing of reversing the opening degree θ in the decreasing direction is earlier than that in the case of Se1 as shown by the alternate long and short dash line. Therefore, the close control is started from a state far away from the coordinate origins (θse, Ps), and the pressure adjustment time becomes long.

(Estimation of effective exhaust speed during pressure regulation)
As described above, if there is an error between the effective exhaust speed stored in advance in the storage unit 240 and the effective exhaust speed of the gas actually flowing, overshoot occurs or the pressure regulation time becomes long. There is a problem of memory. In response to such a problem, in the present embodiment, the effective exhaust speed corresponding to the actually flowing gas is obtained by estimating the effective exhaust speed in the middle of pressure regulation. By using the effective exhaust velocity obtained in this way for the calculation of the predicted pressure and the pressure regulation control, the pressure regulation response is improved.

In the semiconductor process in which the vacuum valve 1 for pressure regulation is used, it is composed of a large number of pressure regulation events in which conditions such as the gas type introduced into the chamber, the gas flow rate Qin, and the target pressure value Ps are changed at predetermined time intervals. .. In each pressure adjustment event, the gas flow rate Qin is converged to a predetermined flow rate value by the flow rate controller 32 immediately after the start, and the pressure is controlled by adjusting the valve body opening of the vacuum valve 1 in parallel to control the effective exhaust speed Se. The measured value (chamber pressure) Pr is converged to the target pressure value Ps.

Generally, the flow rate control convergence completion timing by the flow rate controller 32 is earlier than the pressure control convergence completion timing by the vacuum valve 1. Further, even at the timing of estimating the effective exhaust velocity in the pressure regulation control process, the flow rate value Qin almost converges to a constant value Qin0 at an early stage. The gas type can also be regarded as replacing the changed gas type.

Here, if a period during which the opening degree θ is fixed near the pressure control convergence completion timing is provided, that is, if a period during which the opening degree θ is fixed at the opening degree θse0 in FIG. 5 (t ≧ t0) is provided, the gas type and flow rate Since the opening degree is constant, it can be considered that the effective exhaust speed Se is also a constant value Se0. In that case, the following equations (5) and (6) hold at arbitrary time points t1 and t2 during the period when the opening degree θ is fixed. Pr1 and Pr2 are pressure measurement values at t = t1 and t2, and dPr1 / dt and dPr2 / dt are the temporal pressure change rates of the pressure measurement values at t = t1 and t2. V is the chamber volume, which is obtained by initial calibration or the like and is stored in the storage unit 240.
Qin0 = V × dPr1 / dt + Se0 × Pr1… (5)
Qin0 = V × dPr2 / dt + Se0 × Pr2… (6)

From the equations (5) and (6), the above-mentioned effective exhaust velocity Se0 can be expressed by the following equation (5).
Se0 = −V × (dPr2 / dt−dPr1 / dt) / (Pr2-Pr1)… (7)
By using the equation (7), it is effective from the pressure measurement values Pr1, Pr2 measured at times t1 and t2, the pressure change rates dPr1 / dt, dPr2 / dt, and the chamber volume V stored in the storage unit 240. The exhaust speed Se0 can be estimated.

(Effective exhaust speed ratio a_gs)
Normally, the pressure change rates dPr1 / dt and dPr2 / dt cannot be measured directly, so the difference value of the pressure measurement value is used instead. Since the numerator on the right-hand side of equation (5) = (dPr2 / dt−dPr1 / dt) is the difference in the rate of change in pressure, it is easily affected by the noise of pressure measurement, and its reliability is low as it is. Therefore, in the present embodiment, the following measures are taken.

Data related to the effective exhaust speed and the like are stored in the storage unit 240. For example, the correlation Se (θ) between the effective exhaust speed and the opening degree obtained in the initial calibration, or the valve conductance C (θ) stored in advance in the storage unit 240 at the time of shipment is stored. As described above, since the effective exhaust speed can be considered to be almost the same as the valve conductance in the opening region where the pressure regulation control is performed, the data (Se (θ), C () stored in the storage unit 240. θ))) is expressed as Ser (θ) and is called the reference exhaust speed. This reference exhaust rate Ser (θ) is an effective exhaust rate for a known gas type.

The effective exhaust velocity Se0 calculated by the equation (7) is the effective exhaust velocity at a fixed opening degree θse0. This effective exhaust gas velocity Se0 for which the gas type is unknown can be expressed by the following equation (8) using the reference exhaust gas velocity Ser (θ) for which the gas type is known. In equation (8), the coefficient a_gs is called the effective exhaust speed ratio. Using equation (7), the effective exhaust velocity ratio a_gs is expressed as in equation (9) below.
Se0 ＝ a_gs × Ser (θ)… (8)
a_gs = − (V / Ser (θ)) × (dPr2 / dt−dPr1 / dt) / (Pr2-Pr1)… (9)

(Predicted pressure Pp)
After fixing the opening degree θ to θse0, the predicted pressure Pp thereafter is calculated based on the effective exhaust velocity S (θse0) = Se0. Since it can be considered that the flow rate Qin also converges to the predetermined flow rate value Qin0 as described above, the constants A in the equations (3) and (4) are A = 0. Further, the effective exhaust velocity Se (k × Δt) included in Cp (k) and Cq (k) of the equation (4) depends on the planned value of the opening degree, but the opening degree at t = t0 in FIG. Since θ is fixed, the effective exhaust velocity Se0 at the opening degree θse0 is used for Se (k × Δt). Further, Se0 = a_gs × Ser (θ) may be adopted by using the effective exhaust rate ratio a_gs and the known reference exhaust rate Ser (θ). Further, from the equation (5), it can be expressed as Qin (current) = Qin0 = V × dPr1 / dt + Se0 × Pr1. By applying these to the equations (3) and (4), the predicted pressure Pp ahead of Δt seconds can be calculated.

(Reliability judgment of effective exhaust speed Se0 and effective exhaust speed ratio a_gs)
As described above, in the opening region θ = 0% to about 20% where the pressure regulation control is performed, the effective exhaust speed is almost determined by the valve conductance. In particular, when the opening degree θ is as low as θ <about 5%, the valve conductance is inversely proportional to √M with respect to the molecular weight M of the gas. For example, when the effective exhaust rate when an argon (Ar) gas having a molecular weight M = 40 is exhausted as the reference exhaust rate Ser (θ), the effective exhaust rate ratio a_gs for _{the hydrogen (H 2) gas having a molecular weight M = 2 is} At about 4.5, the effective exhaust rate ratio a_gs for xenone (Xe) gas with a molecular weight of M = 131 is about 0.55. Therefore, the effective exhaust rate ratio a_gs for the gas species from the molecular weight M = 2 to the molecular weight M = 131 is approximately a_gs = 0.55 to 4.5. The exhaust speed of the vacuum pump is dominant in the high opening region, but when a turbo molecular pump is used, the effective exhaust speed ratio a_gs in the high opening region is a_gs = 0.55 to 4.5. It fits within the range.

Therefore, if the effective exhaust rate ratio a_gs calculated by the equation (9) is within the range of 0.55 to 4.5, it can be determined that the calculated effective exhaust rate ratio a_gs is highly reliable. If the calculated effective exhaust rate ratio a_gs is within the range of 0.55 to 4.5, the effective exhaust rate ratio a_gs is adopted, and if it is out of the range, it is not adopted, so that the effective exhaust rate ratio a_gs The reliability of the can be ensured.

Since the effective exhaust speed Se0 calculated by the calculation formula (7) is the effective exhaust speed when the opening degree is constant, the effective exhaust speed ratio a_gs calculated by the formula (9) is ideally constant. Become. Therefore, if the calculated effective exhaust rate ratio a_gs stays in the permissible range (0.55 to 4.5) for a predetermined time, or if the permissible range stays in each of the divided sections divided into a plurality of parts for a predetermined time, It is more preferable that the calculated effective exhaust rate ratio a_gs is determined to be reliable and adopted.

Further, in the effective exhaust speed ratio a_gs calculated by the equation (9), the portion of (dPr2 / dt−dPr1 / dt) is easily affected by the noise of the pressure measurement value Pr. Therefore, in order to reduce the influence of this noise, if the moving average processing of the pressure change rate (difference of the pressure measurement value) and the moving average processing of the effective exhaust speed ratio a_gs itself are performed and the stay judgment is performed, the reliability can be determined. Can be further improved. However, under the condition that the pressure response is extremely fast, the above-mentioned staying time cannot be sufficiently secured, and there is a trade-off between the ratio of successful hiring and the securing of reliability.

FIGS. 9 and 10 show an example of calculating the effective exhaust velocity ratio a_gs in a typical response relationship of an up case in which the pressure rises from the pressure Pstt at the starting point as shown in FIG. FIG. 9 shows a case where the reliability of the effective exhaust speed ratio a_gs is sufficiently secured, and FIG. 10 shows a case where the reliability is insufficient. In FIG. 9, it is estimated that the calculated effective exhaust rate ratio a_gs stays in the allowable range (0.55 to 4.5) for a sufficient time or more, and a_gs = 3.

On the other hand, in the case of FIG. 10, the calculated effective exhaust speed ratio a_gs fluctuates greatly and goes in and out of the permissible range (0.55 to 4.5), and reliability cannot be ensured. In such a case, pressure adjustment control is performed based on the reference exhaust gas speed Ser (θ) for the reference gas type stored in the storage unit 240, that is, assuming that the effective exhaust gas speed ratio a_gs is a_gs = 1.

Since the estimation calculation of the effective exhaust speed Se0 requires a fixed opening condition, the a_gs signal is output from the time t0 or later in FIGS. 9 and 10. Incidentally, the case where the estimated value cannot be determined as in the example of FIG. 10 is likely to occur under the condition that the pressure response is extremely fast or when the SN of the pressure signal (pressure measurement value Pr) is bad.

(Application example of a_gs)
FIGS. 11 and 12 are diagrams showing an example of application of the estimated effective exhaust speed ratio a_gs to pressure regulation control. By using the effective exhaust gas velocity ratio a_gs determined as described above in the calculation of the predicted pressure Pp, the predicted pressure Pp is corrected.

FIG. 11 shows the lines L1A, L1B, L2A and L1C of FIG. 7, where the effective exhaust speed of the gas actually flowing is Se1 and the effective exhaust speed stored in the storage unit 240 is Se2 ( > The case of Se1) will be described. For example, the gas actually flowing is Xe, but it corresponds to the case where the reference exhaust gas velocity Ser (θ) (= Se2) stored in the storage unit 240 is the effective exhaust gas velocity with respect to Ar. t = t20 is the time when the effective exhaust rate ratio a_gs is determined.

The pressure measurement value Pr is represented by the line L1A in the case of the effective exhaust speed Se1. Until the effective exhaust velocity ratio a_gs is determined, that is, at t <t20, the predicted pressure Pp is calculated based on the reference exhaust velocity Ser (θ) = Se2 stored in the storage unit 240. That is, the effective exhaust rate ratio a_gs is a_gs = 1, and the predicted pressure Pp at that time is not the predicted pressure line L1B (Pp') with respect to the line L1A, but the effective exhaust to the pressure measurement value Pr (line L1A). It is given at the line L1C (Pp) when the predicted pressure for the velocity Se2 is applied. Therefore, there is an error in the calculated predicted pressure Pp, which is smaller than the predicted pressure Pp'when the line L1B (Pp') is used.

Based on the estimated effective exhaust velocity Se0, the effective exhaust velocity ratio s is determined as a_gs (= Se0 / Ser (θ) = Se1 / Se2 <1) at t = t20. When the effective exhaust gas velocity ratio a_gs is determined at t = t20, the predicted pressure is calculated based on the determined effective exhaust gas velocity ratio a_gs, that is, the effective exhaust gas velocity Se1 (= a_gs × Se2). ) Is corrected to Pp'with no error. When t ≧ t20, it is determined whether or not the predicted pressure exceeds the determination threshold value (= Ps) by using the predicted pressure Pp'.

FIG. 12 shows the lines L1A, L1B, L3A and L1D of FIG. 7, where the effective exhaust speed of the gas actually flowing is Se1 and the effective exhaust speed stored in the storage unit 240 is Se3 ( The case of <Se1) will be described. For example, the gas actually flowing is He, but it corresponds to the case where the reference exhaust gas velocity Ser (θ) (= Se3) stored in the storage unit 240 is the effective exhaust gas velocity with respect to Ar. t = t20 is the time when the effective exhaust rate ratio a_gs is determined.

The pressure measurement value Pr is represented by the line L1A in the case of the effective exhaust speed Se1. Until the effective exhaust velocity ratio a_gs is determined, that is, at t <t20, the predicted pressure is calculated based on the reference exhaust velocity Ser (θ) = Se3 stored in the storage unit 240. That is, the effective exhaust velocity ratio a_gs is a_gs = 1, and the predicted pressure at that time is effective not on the line L1B (Pp') of the predicted pressure Pp'with respect to the line L1A but on the pressure measurement value Pr (line L1A). It is given by the line L1D (Pp) when the predicted pressure Pp in the case of the exhaust speed Se3 is applied. Therefore, there is an error in the calculated predicted pressure Pp, which is larger than the predicted pressure Pp'when the line L1B (Pp') is used.

Based on the estimated effective exhaust velocity Se0, the effective exhaust velocity ratio s is determined as a_gs (= Se0 / Ser (θ) = Se1 / Se3> 1) at t = t20. When the effective exhaust gas velocity ratio a_gs is determined at t = t20, the predicted pressure is calculated based on the determined effective exhaust gas velocity ratio a_gs, that is, the effective exhaust gas velocity Se1 (= a_gs × Se3). ) Is corrected to Pp'with no error. When t ≧ t20, it is determined whether or not the predicted pressure exceeds the determination threshold value (= Ps) by using the predicted pressure Pp'.

It should be noted that the faster the pressure response is, the closer the pressure measurement value Pr at the timing of establishment of adoption approaches the target pressure value Ps. Therefore, in some cases, the a_gs value is determined after the predicted pressure Pp exceeds the determination threshold value (for example, the target pressure value Ps), and the correction process may not be in time. In that case, the predicted pressure to which the reference gas data (reference exhaust gas speed Ser (θ)) stored in the storage unit 240 is applied, that is, the predicted pressure to which a_gs = 1 is applied in Se0 = a_gs × Ser (θ). The determination of whether or not the determination threshold has been exceeded will be continued using Pp.
The case where the target value Ps of pressure is larger than the pressure Pstt of the starting point has been described above, but conversely, the case where the target value Ps of pressure is smaller than the pressure Pstt of the starting point is also estimated and applied to pressure regulation. It is possible to improve the accuracy of pressure regulation control.

(Application of Se0 and a_gs to the initial calibration process)
In the above-described embodiment, when the opening degree θ is fixed to θse0 during pressure regulation, the effective exhaust velocity Se0 and the effective exhaust velocity ratio a_gs are obtained, and the predicted pressure is corrected or the pressure regulation is controlled by using them. By applying it to, the pressure regulation response was improved. In the following, the application of the effective exhaust speed Se0 and the effective exhaust speed ratio a_gs to the initial calibration process will be described.

The initial calibration process is a process for calibrating the reference gas data (reference exhaust gas speed Ser (θ)) stored in the storage unit 240 to data suitable for an actual vacuum system. When a calibration process command is input to the pressure regulation control unit 21 from an external device (for example, the main controller of the vacuum processing device), the pressure regulation control unit 21 changes from the normal pressure regulation mode to the calibration mode and performs a series of calibration processes. I do. For example, the user operates the operation unit of the main controller of the vacuum processing device according to the manual of the calibration process to transmit a command to the valve control device 1b, and causes the pressure regulation control unit 21 to perform the calibration process.

13 and 14 are flowcharts showing a series of processes in the calibration mode. Further, FIG. 15 is a diagram showing an opening degree measurement value θr (line L31) detected by the encoder 130 during the calibration process and a pressure measurement value Pr (line L32) measured by the vacuum gauge 31. The flowcharts of FIGS. 13 and 14 are executed by the pressure regulation control unit 21, and start when a command for calibration processing is input to the pressure regulation control unit 21 from an external device.

In step S10 of FIG. 13, it is determined whether or not the chamber volume V of the vacuum chamber 3 is stored in the storage unit 240. If the chamber volume V is not stored in the storage unit 240, the process proceeds to step S12 to transmit a command requesting transmission of the chamber volume V to the external device. Hereinafter, the external device will be described as the main controller MC of the vacuum device. The main controller MC displays on the display device or the like of the main controller MC that there is a request command for the chamber volume V, and prompts the user to input the chamber volume V. In step S14, it is determined whether or not the chamber volume V has been received from the main controller MC, and if it is received (yes), it is stored in the storage unit 240 in step S16, and then the process proceeds to step S20.

When it is determined in step S10 that the chamber volume V is stored in the storage unit 240, or when the chamber volume V is stored in step S16, the opening degree is set to θ = 100% in step S20. That is, the opening command θ = 100% is output from the calculation unit 210 of FIG. Here, θ = 100% is set, but it does not have to be 100%. In FIG. 15, when t = t1 is set to θ = 100%, the pressure measurement value Pr (line L32) decreases.

In step S30, a command for flowing a predetermined gas type by a predetermined flow rate Qin0 is transmitted to the main controller MC. The user inputs to the main controller an instruction to inflow the gas of the gas type specified in the manual of the calibration process by the specified predetermined flow rate Qin0. In step S40, it is detected whether or not gas has flowed in from the rise in the pressure measurement value Pr. When the gas inflow is detected in step S40, the process proceeds to step S50 to reduce the opening degree θ from θ = 100% to a predetermined opening degree θtest. In FIG. 15, the gas inflow is detected at t = t3, and the opening degree θ is set to θ = θtest. This opening degree θtest corresponds to the fixed opening degree θse0 in FIG.

When the process of step S50 is completed, the process proceeds to step S60 of FIG. In step S60, the gas flow rate Qin0 is calculated based on the above equations (5) and (6), and the gas type is estimated based on the effective exhaust gas velocity ratio a_gs calculated by the equation (9). The flow rate Qin0 is calculated by the following equation (10) by taking the difference between the one obtained by multiplying both sides of the equation (5) by Pr2 and the one obtained by multiplying both sides of the equation (6) by Pr1.
Qin0 = V × (Pr2 × dPr1 / dt-Pr1 × dPr2 / dt) / (Pr2-Pr1)… (10)
Incidentally, it may be calculated from equations (6) and (8) from Qin0 = V × dPr2 / dt + a_gs × Ser (θtest) × Pr2.

Further, in the equation (9), when the reference exhaust velocity Ser (θ) stored in the storage unit 240 is the valve conductance C (θ), the effective exhaust velocity ratio a_gs is calculated by the following equation (11). .. When the opening degree θtest is small, the influence of the valve conductance on the effective exhaust speed becomes dominant, and the effective exhaust speed Se becomes a value close to the valve conductance C.
a_gs = − (V / C (θtest)) × (dPr2 / dt−dPr1 / dt) / (Pr2-Pr1)… (11)

The effective exhaust speed ratio a_gs calculated by the equation (11) is based on the valve conductance C. As the valve conductance C stored in the storage unit 240 in the initial state, the conductance related to Ar gas is generally used, and the conductance when the Ar gas is flowed will be described below. Therefore, the gas type described in the manual is the same as the gas type of valve conductance C. If the effective exhaust rate ratio a_gs calculated by the formula (11) is approximately 1, it can be determined that Ar gas is introduced as instructed. In consideration of the calculation error of the effective exhaust speed ratio a_gs, a permissible range Δ such as 1 ± Δ may be provided as a judgment criterion, and if 1-Δ ≤ a_gs ≤ 1 + Δ, Ar gas is introduced. judge.

In step S70, it is determined whether or not the gas flow rate Qin0 and the gas type estimated in step S60 satisfy the conditions described in the manual. If the conditions are satisfied, the process proceeds to step S80. On the other hand, if the conditions are not satisfied, that is, if at least one of the gas flow rate Qin0 and the gas type is different from the description in the manual, the main controller MC issues a command D to proceed to step S72 and confirm the gas introduction conditions. And returns to step S40 of FIG.

On the other hand, when the process proceeds from step S70 to step S80, a process of acquiring the pressure measurement value Pr at a plurality of openings θ (i) is performed. It should be noted that i = 1 to N (a positive integer). In the calibration process, the calculation unit 210 outputs a calibration opening command θ (i). In the example shown in FIG. 15, the opening degree θ is changed from 100% to 0% at t = t11. Although the pressure measurement value Pr increases due to the change in the opening degree, the pressure measurement value Pr (1) is acquired when the pressure measurement value Pr becomes stable and almost constant. Similarly, at the times t12, t13, ..., T1N in FIG. 15, the opening command θ (i) is output in the order of θ (2), θ (3), ..., θ (N), and each of them is output. On the other hand, the pressure measurement values Pr (2), Pr (3), ..., Pr (N) are acquired. That is, the pressure measurement value Pr (θ (i)) is obtained for N opening degrees θ (i).

In step S90, the effective exhaust gas velocity Se (θ (i)) is calculated by the following equation (12) using the gas flow rate Qin0 and the acquired pressure measurement value Pr (θ (i)). Strictly speaking, equation (11) is an equation that holds in the equilibrium state, but by setting the time intervals of t11, t12, t13, ..., T1N in FIG. 15 to be sufficiently large, the equilibrium state is substantially satisfied.
Se (θ) = Qin0 / P (θ)… (12)

In the calculation of the effective exhaust velocity in steps S80 and S90, the effective exhaust velocity Se (θ) was calculated from the equation (12) after waiting until the pressure measurement value Pr after the opening change was almost converged. , The pressure change rate may be acquired and the effective exhaust velocity Se (θ) may be calculated by the equation (7). In this case, since it is not necessary to wait until the pressure measurement value Pr is substantially converged, the time required for the calibration process can be shortened.

In step S100, the effective exhaust velocity Se (θ (i)) acquired by the calibration process is stored in the storage unit 240 of the pressure regulation control unit 21. If the effective exhaust speed Se is stored in the storage unit 240 in advance, the effective exhaust speed Se may be corrected by the effective exhaust speed Se (θ (i)) obtained by the calibration process, or as it is. Rewrite.

As described above, by providing steps S70 and S72 and confirming whether the user is inflowing the gas type according to the manual by a predetermined flow rate Qin0, the calibration process is performed with the wrong gas type and flow rate. Can be prevented. If the gas type and flow rate do not follow the manual, the pressure regulation accuracy will decrease, but by performing the calibration process as described above, such pressure adjustment accuracy can be prevented from decreasing.

In the flowchart shown in FIG. 13, the processes from step S10 to step S16 are provided so that the user can input the chamber volume V when the chamber volume V is not stored in the storage unit 240. However, the chamber volume is input by the build-up method. May be estimated and stored in the storage unit 240. In the build-up method, not only the valve body opening is set to 0%, but also the pressure change when the gas introduction amount Qin is fixed in the state where the valve body is pressed and completely sealed (effective exhaust speed = 0). From the rate dP / dt, the chamber volume V is calculated by the following equation (13).
V = Qin / (dP / dt)… (13)

Further, the gas type for calibration is not limited to Ar gas, and for example, the gas type may be selected from Ar gas and nitrogen gas. In that case, since the valve conductance C stored in the storage unit 240 is a value when Ar gas is flowed, the effective exhaust rate ratio a_gs = 1 in the case of Ar gas in the storage unit 240 and nitrogen based on Ar gas. The effective exhaust rate ratio of gas a_gs = 1.2 is stored. When the user selects Ar gas as the gas type to be introduced, a_gs = 1.2 for nitrogen gas is selected as the effective exhaust gas rate ratio a_gs used for determining the gas type based on the selection information. That is, when the value of the effective exhaust gas rate ratio a_gs calculated in step S60 is approximately 1.2, it can be determined that the introduction conditions are satisfied if the nitrogen gas as declared by the user is introduced.

It will be understood by those skilled in the art that the above-described exemplary embodiments are specific examples of the following embodiments.

[1] The valve control device according to one aspect is a valve that controls the valve body opening degree based on a pressure measurement value of a chamber equipped with a vacuum valve and a pressure target value of the chamber, and adjusts the pressure of the chamber. In the control device, based on the opening setting unit that fixes the valve body opening constant when the gas is introduced into the chamber, and the change information of the pressure measurement value when the valve body opening is fixed constant. Therefore, an estimation unit for estimating the exhaust information of the vacuum valve is provided, the valve body opening degree is controlled based on the exhaust information, and the pressure adjustment control of the chamber is performed.

For example, the calculation unit 210 of FIG. 2 functions as an estimation unit and an opening degree setting unit, and the calculation unit 210 is information on changes in the pressure measurement value when the valve body opening degree is fixed at a constant value θse0, that is, pressure. The effective exhaust speed Se0 calculated by the formula (7), the effective exhaust speed ratio a_gs calculated by the formula (9), and the flow rate calculated by the formula (10) based on the rate of change dPr1 / dt and dPr2 / dt. Estimate Qin0 as exhaust information. Since these are exhaust information according to the type of gas actually flowing, the accuracy of pressure adjustment control can be improved by calculating the predicted pressure Pp and performing pressure adjustment control based on the estimated exhaust information. Can be planned.

[2] The valve control device according to the above [1] further includes a predicted pressure calculation unit that calculates a predicted pressure value after a lapse of a predetermined time with respect to the measured pressure value based on the exhaust information, and further includes the predicted pressure value. When the pressure exceeds the upper limit threshold value, the valve body opening degree is increased, or when the pressure predicted value exceeds the lower limit threshold value, the valve body opening degree is decreased.

As shown in FIG. 11 t ≧ t20, the estimated effective exhaust speed is the effective exhaust speed Se1 corresponding to the gas type of the gas actually flowing, and the pressure predicted value calculated using the effective exhaust speed Se1. (Predicted pressure) is the predicted pressure Pp'with no error represented by the line L1B. As a result, it is possible to prevent the timing of reversing the valve body opening θ in the increasing direction from being delayed or advanced, and overshooting occurs in the pressure response, and conversely, the pressure adjusting time becomes long. Can be prevented. Since there is a relationship between the estimated effective exhaust gas speed (Se0), the effective exhaust gas speed ratio a_gs, and the equation (8), the effective exhaust gas speed ratio a_gs, which is gas type information, is estimated as the exhaust information, and the estimated effective exhaust gas. The predicted pressure value may be calculated from the velocity ratio a_gs and the equation (8).

[3] In the valve control device according to the above [1], the exhaust information includes gas type information of the gas introduced into the chamber, and the estimation unit includes the reference exhaust rate and the change information regarding the reference gas. The gas type information is estimated based on the above. The effective exhaust rate ratio a_gs, which is one of the exhaust information, is a value corresponding to the gas type of the gas introduced into the vacuum chamber 3 as shown in the equation (8), and is a value according to the gas type as shown in the equation (9). It is estimated based on the reference exhaust rate Ser for the reference gas (for example, Ar gas), the pressures Pr1 and Pr2, and the pressure change rates dPr1 / dt and dPr2 / dt.

[4] In the valve control device according to the above [1], the exhaust information includes information on at least one of the flow rate and the gas type of the gas introduced into the chamber, and the estimated exhaust information is the reference flow rate and the reference. It includes a determination unit for determining whether or not the gas type matches, and an output unit for outputting the determination result of the determination unit.

As shown in the calibration process shown in FIGS. 13 and 14, the flow rate and gas type of the gas introduced into the vacuum chamber 3 are estimated as exhaust information (step S60), and the estimated gas flow rate and the estimated gas flow rate and the gas flow rate are based on the estimation result. It is determined whether or not the gas type matches the gas flow rate (reference flow rate) and the gas type (reference gas type) specified in the manual (step S70), and the determination result is output (step S72). The user can recognize that the introduction conditions (gas flow rate and gas type) of the introduced gas are different from the reference introduction conditions (reference flow rate and reference gas type) based on the determination result (condition confirmation command D). , The calibration process can be performed under the correct gas introduction conditions.

[5] The estimation device according to one aspect is an estimation device that estimates the exhaust information of the vacuum valve mounted on the chamber, and is a pressure measurement value of the chamber when the valve body opening degree of the vacuum valve is constant. Based on the change information, at least one of the valve exhaust speed, the flow rate of the gas introduced into the chamber, and the gas type information of the gas is estimated as the exhaust information. By using the estimation result for valve control, the predicted pressure Pp can be calculated and the pressure adjustment control can be performed based on the estimated exhaust information, and the accuracy of the pressure adjustment control can be improved. The estimation device may be configured independently of the valve control device, or may be configured to be incorporated in the valve control device.

Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other aspects conceivable within the scope of the technical idea of the present invention are also included within the scope of the present invention. For example, in the above-described embodiment, the calibration process is performed by the pressure adjusting control unit 21 of the valve control device 1b, but a calibration device independent of the valve control device 1b is provided and calibrated according to the command of the calibration device. The processing may be performed.

1 ... Vacuum valve, 1a ... Valve body, 1b ... Valve control device, 3 ... Vacuum chamber, 12 ... Valve body, 21 ... Pressure regulation control unit, 210 ... Calculation unit, Pr ... Pressure measurement value, Ps ... Pressure target value, Pp ... Predicted pressure

Claims (5)

In a valve control device that controls the valve body opening degree based on the pressure measurement value of the chamber equipped with the vacuum valve and the pressure target value of the chamber to adjust the pressure of the chamber.
An opening setting unit that fixes the valve body opening constant when gas is introduced into the chamber, and an opening setting unit.
It is provided with an estimation unit that estimates the exhaust information of the vacuum valve based on the change information of the pressure measurement value when the valve body opening degree is fixed to be constant.
A valve control device that controls the valve body opening degree based on the exhaust information and controls the pressure adjustment of the chamber. In the valve control device according to claim 1,
Further, a predicted pressure calculation unit for calculating a pressure predicted value after a lapse of a predetermined time with respect to the pressure measured value based on the exhaust information is provided.
A valve control device that increases the valve body opening degree when the pressure predicted value exceeds the upper limit threshold value, or decreases the valve body opening degree when the pressure predicted value exceeds the lower limit threshold value. In the valve control device according to claim 1,
The exhaust information includes gas type information of the gas introduced into the chamber.
The estimation unit is a valve control device that estimates the gas type information based on the reference exhaust speed with respect to the reference gas and the change information. In the valve control device according to claim 1,
The exhaust information includes information about at least one of the flow rate and the gas type of the gas introduced into the chamber.
A determination unit for determining whether or not the estimated exhaust information matches the reference flow rate and the reference gas type, and
A valve control device including an output unit that outputs a determination result of the determination unit. It is an estimation device that estimates the exhaust information of the vacuum valve installed in the chamber.
At least one of the valve exhaust speed, the flow rate of the gas introduced into the chamber, and the gas type information of the gas, based on the change information of the pressure measurement value of the chamber when the valve body opening degree of the vacuum valve is constant. An estimation device that estimates one as the exhaust information.

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