KR101117747B1 - Vacuum pressure control system - Google Patents

Abstract

This invention is made | formed in order to provide the vacuum pressure control system which can detect the abnormality of the system, such as the abnormality of a vacuum pressure sensor, the leakage of a reaction chamber, the blockage of piping, etc. early, and using the potentiometer 18, When the valve opening degree of the obtained vacuum proportional opening / closing valve 16 reaches the preset set value X1 (S22: YES), the vacuum pressure of the reaction chamber 10 obtained using the pressure sensors 14, 15 is When larger than the preset value X2 (S24: NO), it is determined that abnormalities in the system, such as an abnormality in the vacuum pressure sensor, a leak in the reaction chamber, a blockage in the pipe, and the like, are processed (S25). The set values X1 and X2 are obtained in advance by experiment or the like so that various abnormalities such as abnormality of the vacuum pressure sensor, leakage of the reaction chamber, clogging of the pipe and the like can be properly detected.

Vacuum pressure sensor, vacuum pressure control system, vacuum proportional open / close valve,

Description

Vacuum pressure control system {VACUUM PRESSURE CONTROL SYSTEM}

The present invention relates to a vacuum pressure control system used in a semiconductor manufacturing apparatus. More specifically, the present invention relates to a vacuum pressure control system capable of detecting various abnormalities of the system.

Background Art Conventionally, for example, in a CVD apparatus of a semiconductor manufacturing apparatus, a material gas of an element constituting a thin film material is supplied onto a wafer while maintaining the inside of the reaction chamber in a reduced pressure state, that is, in a vacuum state. For example, in the CVD apparatus shown in FIG. 14, a material gas is supplied from the inlet 11 of the reaction chamber 10 to a wafer in the reaction chamber 10, which is a vacuum vessel, and the reaction chamber 10. The inside of the reaction chamber 10 is maintained in a vacuum state by evacuating the outlet 12 from the outlet to the vacuum port 13.

At this time, it is necessary to keep the vacuum pressure in the reaction chamber 10 constant, but the constant value is changed by various conditions, and it is from the low vacuum close to atmospheric pressure or atmospheric pressure to the high vacuum. Reach a wide range. Therefore, it is necessary to reach a wide range from low vacuum to high vacuum close to atmospheric pressure, and to maintain the vacuum pressure precisely and satisfactorily. In addition, in order to further improve the quality of the thin film formed on the wafer in the reaction chamber 10, in view of preventing particles from rising into the reaction chamber 10, the vacuum pressure in the reaction chamber 10 is close to atmospheric pressure or atmospheric pressure. In the vacuumization process reaching from the low vacuum to the target vacuum pressure value, it is also necessary to sufficiently proceed the gas discharge process in the reaction chamber 10.

As a vacuum pressure control system for satisfying such a need, there is disclosed, for example, in Japanese Patent Laid-Open No. 2000-163137. In this system, a process of discharging the gas in the vacuum container by manipulating the opening degree of the vacuum proportional opening / closing valve to further change the target vacuum pressure change rate given to the vacuum pressure in the vacuum container externally or previously set in the controller. Is sufficiently performed to prevent the particles from rising in the vacuum vessel and to freely control the rate of change of the vacuum pressure in the vacuum vessel when discharging the gas in the vacuum vessel.

More specifically, the vacuum pressure value changed at the target vacuum pressure change rate obtained with respect to the vacuum pressure in the reaction chamber measured by the vacuum pressure sensor is sequentially generated as an internal command, and the feedback generated is sequentially controlled. It is set as the target value of, and the feedback control is executed as the following control by sequentially changing the target value of the feedback control. Thereby, in this vacuum pressure control system, the vacuum pressure in a reaction chamber can change the target vacuum pressure change rate more uniformly.

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-163137

However, in the above-described conventional vacuum pressure control system, for example, an abnormality such as "an abnormality of the vacuum pressure sensor", "leak of the reaction chamber", "clog of the piping", or the like, may be caused by an operator or the like. After that is found, the countermeasure is executed. That is, there is a problem that it is not possible to detect an abnormality in the system itself.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a vacuum pressure control system capable of detecting an abnormality of a system such as an abnormality of the vacuum pressure sensor, leakage of the reaction chamber, clogging of the pipe, and the like. Shall be.

The vacuum pressure control system which concerns on this invention made | formed in order to solve the said subject is a vacuum proportional opening-closing which changes the vacuum pressure in the said vacuum container by changing the opening degree on the piping which connects a vacuum container and a vacuum pump. In the vacuum pressure control sensor which has a valve, the vacuum pressure sensor which measures the vacuum pressure in the said vacuum container, and the controller which controls the opening degree of the said vacuum proportional opening-closing valve based on the output of the said vacuum pressure sensor, The said controller is, The relationship between the output of the vibration pressure sensor when the system is operating normally and the opening degree of the vacuum proportional on / off valve is stored in advance, and the opening degree control of the vacuum proportional on / off valve based on the output of the vacuum pressure sensor is controlled. When performing, the actual output of the vacuum pressure sensor and the vacuum proportional opening / closing valve Characterized in that for detecting the abnormality of the system by comparing the relationship between the relationship and the stored output of said vacuum pressure sensor and the vacuum pressure proportional opening and closing of the valve opening degree and the actual opening degree.

In this vacuum pressure control system, the controller controls the opening degree of the vacuum proportional opening / closing valve based on the vacuum pressure sensor which measures the vacuum pressure in the vacuum container, and the output of the vacuum pressure sensor, and lowers the pressure in the vacuum container (FIG. 5). Reference). Here, when the system is normal, the output of the vacuum pressure sensor and the opening degree of the vacuum proportional open / close valve always have a constant relationship. Therefore, in this vacuum pressure control system, the controller stores the relationship between the output of such a normal vacuum pressure sensor and the opening degree of the vacuum proportional opening / closing valve.

In the vacuum pressure control system, when an abnormality such as an abnormality of the vacuum pressure sensor, a leak of the vacuum vessel, a blockage of the piping, or the like occurs, the output of the vacuum pressure sensor and the vacuum proportional valve The relationship of opening degree collapses. In other words, the relationship between the actual output of the vacuum pressure sensor and the actual opening degree of the vacuum proportional open / close valve does not match the relationship stored in the controller. Therefore, when the opening degree control of the vacuum proportional on / off valve based on the output of the vacuum pressure sensor is being performed, the relationship between the actual output of the vacuum pressure sensor and the actual opening degree of the vacuum proportional on / off valve and the vacuum stored in the controller By comparing the relationship between the output of the pressure sensor and the opening degree of the vacuum proportional on / off valve, it is possible to detect the abnormality of the system earlier.

Moreover, the vacuum pressure control system of another form which concerns on this invention made in order to solve the said subject is on the piping which connects a vacuum container and a vacuum pump, and the vacuum proportion which changes the vacuum pressure in the said vacuum container by changing an opening degree. A vacuum pressure control system having an on / off valve, a vacuum pressure sensor for measuring a vacuum pressure in the vacuum vessel, and a controller for controlling the opening degree of the vacuum proportional on / off valve based on an output of the vacuum pressure sensor. And when the opening degree of the vacuum proportional valve is reached based on the output of the vacuum pressure sensor, when the opening degree of the vacuum proportional valve reaches a predetermined opening degree, the predetermined output of the vacuum pressure sensor is preset. If it is larger than the value, it is determined that the system is having an error. And that is characterized.

Also in this vacuum pressure control system, the controller controls the opening degree of the vacuum proportional opening / closing valve based on the vacuum pressure sensor which measures the vacuum pressure in a vacuum container, and the output of a vacuum pressure sensor, and lowers the pressure in a vacuum container (FIG. 5). Reference). Here, when the system is normal, the output of the vacuum pressure sensor and the opening degree of the vacuum proportional open / close valve always have a constant relationship. For this reason, it is possible to predict the output of the vacuum pressure sensor when the opening degree of the said vacuum proportional opening / closing valve reaches predetermined preset opening degree.

And since the pressure in a vacuum container is falling, when the opening degree of a vacuum proportional opening / closing valve reaches predetermined preset opening, when the output of a vacuum pressure sensor is larger than predetermined value, it is thought that an abnormality has occurred in a system. do. Therefore, in this vacuum pressure control system, when the opening degree control of the vacuum proportional on / off valve based on the output of the vacuum pressure sensor is performed, when the opening degree of the vacuum proportional opening / closing valve reaches a predetermined predetermined opening degree, If the output is larger than a predetermined value, it is determined that an abnormality has occurred in the system. Thereby, it is possible to detect abnormality of a system early.

Here, the predetermined opening degree of the vacuum proportional opening / closing valve set to detect the abnormality of the system and the predetermined opening degree of the vacuum pressure predecessor may be obtained by experiment or the like most suitable for the abnormality to be detected. Therefore, the combination of the predetermined opening degree of the preset vacuum proportional opening-closing valve and the predetermined opening degree of the vacuum pressure sensor may be a pair, or there may be a plurality of pairs.

In the vacuum pressure control system according to the present invention, the controller may use an operating voltage input to the vacuum proportional open / close valve instead of the opening degree of the vacuum proportional open / close valve to detect an abnormality of the system.

Alternatively, in the vacuum pressure control system according to the present invention, the controller may use the operating air pressure supplied to the vacuum proportional opening / closing valve instead of the opening degree of the vacuum proportional solenoid valve to detect an abnormality of the system. .

By doing in this way, even if a system is constructed by the valve which is not equipped with the structure which detects the opening degree of a vacuum proportional opening / closing valve (for example, potentiometer etc.), it detects the abnormality of a system early. It is possible.

In the vacuum pressure control system according to the present invention, when the controller detects an abnormality of the system or determines that an abnormality has occurred in the system, it is preferable to notify the controller.

This allows the operator to know the abnormality of the system at an early stage, and the subsequent countermeasures can be performed quickly. In addition, a "notice" includes all things about hearing, a thing about time, etc., and the notification by a single means (for example, a warning sound only, etc.) or the notification by a combined means (for example, a warning sound and a warning indication). Etc.) may be sufficient.

In the vacuum pressure control system according to the present invention, it is preferable that the controller operates the vacuum proportional valve in the safety direction of the system when detecting the abnormality of the system or determining that the abnormality is occurring in the system.

Here, since the safety direction of the system varies depending on the configuration of each system, in "Operating the vacuum proportional valve in the safety direction of the system", "close the valve", "open the valve", or "maintain the valve opening degree." It will correspond to either. That is, in this vacuum pressure control system, in order to improve stability of each system at the time of abnormality, operation | movement of a vacuum proportional opening / closing valve is controlled by a controller. For this reason, it is possible to automatically deal with an abnormality, so that the stability of the system can be further improved.

According to the vacuum pressure control system according to the present invention, it is possible to detect abnormality of the system such as abnormality of the vacuum pressure sensor, leakage of the reaction chamber, clogging of the pipe, etc. by the above means.

1 is a block diagram showing an outline of a vacuum pressure control system of an embodiment.

2 is a cross-sectional view when the vacuum proportional valve is in a closed state.

3 is a cross-sectional view when the vacuum proportional valve is in an open state.

4 is a block diagram showing an outline of a vacuum pressure control system of the embodiment.

FIG. 5 is a diagram showing a state in which the conductance (valve opening) of the vacuum proportional open / close valve is changed in the vacuum pressure change speed control mode to lower the pressure in the reaction chamber at a predetermined constant speed.

6 is a flow chart showing the processing contents of the vacuum pressure change speed control mode.

7 is a flowchart showing the contents of preparation time processing in the vacuum pressure change speed control mode.

8 is a flowchart showing the execution time processing contents of the vacuum pressure change speed control mode.

It is a figure which shows an example of the change of the pressure of the reaction chamber and the valve opening degree of a vacuum proportional opening / closing valve in the vacuum pressure change speed control mode at the time of normality.

FIG. 10 is a diagram showing an input signal of a process of raising the amount of lift of the valve. FIG.

It is a figure which shows an example of the change of the pressure change of the reaction chamber and the valve opening degree of a vacuum proportional opening-closing valve, when an abnormality is detected and a process at the time of abnormality is performed.

It is a figure which shows an example of the change of reaction chamber pressure and the valve opening degree of a vacuum proportional opening-closing valve in case an abnormality is detected and a process at the time of abnormality is performed.

It is a figure which shows an example of a change of reaction chamber pressure and the valve opening degree of a vacuum proportional opening-closing valve when an abnormality is detected and a process at the time of abnormality is performed.

14 is a diagram showing an outline of a CVD apparatus and an exhaust system thereof.

Explanation of the sign

10 Reaction chamber of CVD apparatus

14, 15 vacuum pressure sensor

16 vacuum proportional open / close valve

18 potentiometer

20 controller

EMBODIMENT OF THE INVENTION Hereinafter, the most suitable embodiment which actualized the vacuum pressure control system of this invention is described in detail based on drawing. 1 shows a block diagram of the vacuum pressure control system according to the present embodiment with respect to FIG. 14 shown in the column of the prior art. The vacuum pressure control system according to the present embodiment uses the controller 20, the air pressure control unit 30, the vacuum proportional opening / closing valve 16 as the operation unit 40, and the vacuum pressure sensors 14 and 15 as the detection unit 60. Include.

The controller 20 includes an interface circuit 21, a vacuum pressure control circuit 22, and a sequence control circuit 23. The interface circuit 21 receives a signal by field input using a button of a front valve of the controller 20 and a signal by remote input using a connector of a rear valve of the controller 20. The signal is converted into a signal suitable for the vacuum pressure control circuit 22, the sequence control circuit 23, or the like. In addition, the controller 20 stores a constant relationship between the output of the vacuum pressure sensor during normal operation and the opening degree of the vacuum proportional opening / closing valve, as will be described later. It compares the relationship of the actual opening degree of a switching valve, and detects (decides) abnormality of a system.

The vacuum pressure control circuit 22 is a circuit which executes feedback control with respect to the vacuum pressure in the reaction chamber 10 of FIG. 14 by PID control. The sequence control circuit 23 drives the driving coil SV1 of the first solenoid valve 34 and the second solenoid valve 35 in the pneumatic pressure control unit 30 according to the operation mode given by the interface circuit 21. It is a circuit which makes a predetermined operation | movement with respect to the coil SV2.

The pneumatic control unit 30 includes a position control circuit 31, a pulse drive circuit 32, a time opening / closing operation valve 33, a first solenoid valve 34, and a second solenoid valve 35. do. The position control circuit 31 has a valve opening command value given by the vacuum pressure control circuit 22 and a valve given using an amplifier 19 in the potentiometer 18 provided in the vacuum proportional opening / closing valve 16. The opening degree measurement value is compared and the position of the valve of the vacuum proportional opening / closing valve 16 is controlled. The pulse drive circuit 32 transmits a pulse signal to the time opening / closing operation valve 33 based on the control signal from the position control circuit 31.

The time opening / closing operation valve 33 incorporates an air supply side proportional valve and an exhaust side proportional valve (not shown), and respond to a pulse signal from the pulse drive circuit 32. And opening / closing the air supply side proportionality valve and the exhaust side proportional valve for a time, and using the second solenoid valve 35 and the first solenoid valve 34, the pneumatic cylinder 41 of the vacuum proportional open / close valve 16 ( 2 and 3 to be described later).

As for the vacuum proportional opening / closing valve 16 which is the operation part 40, as for FIG. 14, the conductance of the exhaust system from the reaction chamber 10 to the vacuum pump 13 is changed. 2 and 3 show cross-sectional views of the vacuum proportional open / close valve 16. As shown in the figure, the piston rod 43 is provided in the center. And the piston 44 is fixed to the piston rod 43 in the pneumatic cylinder 41 which is the upper part of the vacuum proportional opening / closing valve 16, and bellows which is lower part of the vacuum proportional opening / closing valve 16. In the poppet valve 42, the poppet valve body 45 is fixed. Therefore, it is possible to move the poppet valve main body 45 by the pneumatic cylinder 41.

In this vacuum proportional opening / closing valve 16, compressed air is not supplied into the pneumatic cylinder 41 using the supply port 18A, and the pneumatic cylinder 41 communicates with the exhaust line using the exhaust port 18B. At this time, since the downward force applied by the return plate 46 in the pneumatic cylinder 41 acts on the piston 44, the poppet valve body 45 is in close contact with the valve seat 47 as shown in FIG. And the vacuum proportional open / close valve 16 is shut off.

On the other hand, when compressed air is supplied into the pneumatic cylinder 41 using the air supply port 18A, downward force applied by the return plate 46 in the pneumatic cylinder 41 and compressed air in the pneumatic cylinder 41 are applied. Since the upward pressure by the two acts on the piston 44 simultaneously, according to this balance, as shown in FIG. 3, the poppet valve body 45 falls off the valve seat 47, and the vacuum proportional on / off valve 16 Becomes open.

Therefore, the distance which the poppet valve main body 45 separated from the valve seat 47 can operate with supply and exhaust of compressed air with respect to the pneumatic cylinder 41 as an amount of lift of a valve. In addition, the distance which the poppet valve main body 45 separated from the valve seat 47 is measured by the potentiometer 18 using the slide lever 48 connected to the piston 44 as an amount of lift of a valve. This corresponds to the opening degree of the vacuum proportional on / off valve 16.

The vacuum pressure sensors 14 and 15 which are detection parts are capacitance manometers which measure the vacuum pressure in the reaction chamber 10 of FIG. Here, two capacitance manometers are divided and used according to the measured vacuum pressure range.

In the vacuum pressure control system according to the present embodiment having such a configuration, when the forced closing mode CLOSE is selected by the controller 20 as the operation mode, the sequence control circuit 23 performs the first solenoid valve ( 34 and the second solenoid valve 35 are operated as shown in FIG. Thereby, since compressed air is not supplied to the pneumatic cylinder 41, and the pneumatic cylinder 41 communicates with an exhaust line, the air pressure in the pneumatic cylinder 41 becomes atmospheric pressure, and the vacuum proportional opening / closing valve 16 It is blocked.

In addition, when the vacuum pressure control mode PRESS is selected by the controller 20 as the operation mode, the sequence control circuit 23 operates the first solenoid valve 34 to operate the time opening / closing operation valve ( 33) and the pneumatic cylinder 41 are communicated. Thereby, the air pressure in the pneumatic cylinder 41 of the vacuum proportional opening / closing valve 16 is adjusted, and the amount of rise of the valve will be in the state which can be operated by the pneumatic cylinder 41.

In addition, at this time, the vacuum pressure control circuit 22 starts feedback control which makes the target vacuum pressure value instruct | indicated by a site input or a remote input as a target value. That is, in Fig. 14, the vacuum pressure sensors 14 and 15 measure the vacuum pressure value in the reaction chamber 10, and in accordance with the difference (control deviation) between the target vacuum pressure value and the vacuum proportional opening / closing valve ( By operating the valve lift amount of 16) and changing the conductance of the exhaust system, the vacuum pressure in the reaction chamber 10 is kept constant at the target vacuum pressure value.

Moreover, in the vacuum pressure control circuit 22, when the control deviation of feedback control is large, since the operation amount of feedback control is maximized, the speed responsiveness of feedback control is fully ensured. On the other hand, when the control deviation of the feedback control is small, the process shifts to a predetermined time constant step by step, so that the vacuum pressure in the reaction chamber 10 can be maintained in a stable state.

Specifically, as shown in the block diagram of FIG. 4, a value in which the vacuum pressure values in the reaction chamber 10 measured by the vacuum pressure sensors 14 and 15 are adjusted by the proportional differential circuits 105 and 106. Is compared with the target vacuum pressure value indicated by the field input or the remote input, and is then input to the proportional integration circuits 102 and 103. Then, since the integrating circuit 104 connected in series outputs to the input control circuit 31, it outputs the voltage of the range of 0-5V. The time constant of the integration circuit 104 is determined by the integration time adjustment circuit 101.

When the measured values of the vacuum pressure sensors 14 and 15 are separated from the target vacuum pressure value, the internal arithmetic circuit operates so that the integration time of the integrating circuit is extremely small. As a result, the integrating circuit 104 functions as an amplifying circuit for sustaining infinite deigns.

In other words,

(Measured value of vacuum pressure sensors 14 and 15)> (Target vacuum pressure value)

In this case, 5 V which is the maximum value of the integrating circuit 104 is output to the position control circuit 31. As a result, the vacuum proportional opening / closing valve 16 operates in a rapidly opening direction. Meanwhile,

(Measured values of vacuum pressure sensors 14 and 15) <(target vacuum pressure value)

In this case, 0 V, which is the minimum value of the integrating circuit 104, is output to the position control circuit 31. As a result, the vacuum proportional opening / closing valve 16 operates in a rapidly closing direction.

By this operation, the valve opening degree of the vacuum proportional opening / closing valve 16 can be reached in the shortest time to the vicinity of the position to be the target vacuum pressure value. Thereafter, the integral time adjustment circuit 101 determined to have reached the vicinity of the position to be the target vacuum pressure value, in order to maintain the vacuum pressure at a stable state at that position, the time constant of the integrated circuit 104 previously adjusted. The operation of shifting step by step is performed.

In addition, in the vacuum pressure control system according to the present embodiment, when the controller 20 selects the vacuum pressure change speed control mode (SVAC) as the operation mode, the vacuum pressure in the reaction chamber 10 is set to the target vacuum pressure. When it reaches | attains, it is possible to control even the vacuum pressure change rate in the reaction chamber 10.

In this way, in the vacuum pressure change speed control mode (SVAC), by performing feedback control, the conductance (valve opening) of the vacuum proportional open / close valve 16 is changed as shown in FIG. 5 to react at a predetermined constant speed. The pressure in the chamber 10 is reduced. For this reason, in a vacuum pressure control system, when abnormality, such as "the abnormality of the vacuum pressure sensors 14 and 15", the "leakage of the reaction chamber 10", or the "clogging of the piping," occurs, a vacuum At the time in the pressure change speed control mode SVAC, the relationship between "valve opening degree of the vacuum proportional valve 16" and "value of the vacuum pressure sensors 14 and 15" does not become as shown in FIG. By using this phenomenon, the above abnormality is detected in the vacuum pressure control valve system according to the present embodiment.

Therefore, the operation | movement of the vacuum pressure control system which concerns on this embodiment is demonstrated, referring FIGS. 6-9. 6 is a flowchart of a vacuum pressure change speed control mode (SVAC). 7 is a flowchart showing the preparation time of the vacuum pressure change speed control mode (SVAC). 8 is a flowchart illustrating an execution time of the vacuum pressure change speed control mode (SVAC). FIG. 9: is a figure which shows an example of the change of the pressure of the reaction chamber and the valve opening degree of the vacuum proportional opening-closing valve 16 in the vacuum pressure change speed control mode (SVAC) at the time of normality. In addition, it is assumed that the vacuum pressure change speed control mode SVAC moves in the forced closing mode CLOSE.

As shown in FIG. 6, the vacuum pressure change speed control mode SVAC executes two sub routines, namely, preparation time processing and execution time processing. Then, when the vacuum pressure change speed control mode (SVAC) is selected by the controller 2, first, preparation time processing is executed.

Then, first, the present vacuum pressure in the reaction chamber 10 is obtained using the vacuum pressure sensors 14 and 15 (S1). Here, since the present vacuum pressure in the reaction chamber 10 is atmospheric pressure V0 (refer FIG. 9), atmospheric pressure V0 is obtained.

Next, the valve opening degree of the vacuum proportional opening / closing valve 16 is obtained using the potentiometer 18 (S2). Then, it is judged whether or not the obtained valve opening degree reaches the set value X1 (S3). At this time, when the valve opening degree reaches the set value X1 (S3: YES), the present vacuum pressure in the reaction chamber 10 is obtained using the vacuum pressure sensors 14 and 15 (S4). Then, it is determined whether the present vacuum pressure in the obtained reaction chamber 10 is equal to or less than the set value X2 (S5). At this time, when the present vacuum pressure in the reaction chamber 10 is larger than the set value (X2) (S5: NO), it is determined that an abnormality has occurred, and when the vacuum pressure change speed control mode (SVAC) is terminated, The process is performed (S6).

Here, the set value X1 is a threshold amount because abnormality detection (judgment) of the system is performed. That is, when the valve opening degree of the vacuum proportional opening / closing valve 16 reaches the set value X1, the abnormality detection process of the system is performed. The set value X2 is a threshold value because it determines whether an abnormality has occurred in the system when the abnormality detection processing is executed. That is, the abnormality detection process is performed, and when the present vacuum pressure in the reaction chamber 10 is larger than the set value X2, it is determined that the abnormality has occurred in the system.

On the other hand, when the valve opening degree does not reach the set value X1 (S3: NO), or when the present vacuum pressure in the reaction chamber 10 is equal to or lower than the set value X2 (S5: YES), the valve lift amount The process of raising the (S7). Since the shift is made in the forced closing mode CLOSE here, when the vacuum pressure change speed control mode SVAC is selected, the vacuum proportional open / close valve 16 is in a blocked state. Thus, as shown in FIG. 10, the bias control circuit 110 outputs the intelligence voltage to the position control circuit 31 so that the lifting of the valve lift amount of the vacuum proportional open / close valve 16 changes functionally, The position control circuit 31 sends a control signal to the pulse drive control circuit 32 (see FIG. 4). Here, as an example, the time t1 is set to 10 seconds, and the value of the lift amount of the valve is set to 0.1266 mm.

Then, it is determined whether 10 seconds, which is the time t1, has passed (S8). When it is determined that 10 seconds, which is the time t1 (S8: YES), the process proceeds to S11. When it is determined that 10 seconds, which is the time t1, has not elapsed (S3: NO), the process proceeds to S9, and the reaction chamber 10 The current vacuum pressure within is obtained using the vacuum pressure sensors 14, 15. Thereafter, it is determined whether there is a slight pressure drop with respect to the vacuum pressure in the reaction chamber 10 (S10). When it is judged that there is no slight pressure drop (S10: NO), the flow returns to S2 and the above-described processing is repeated. In this case, the slight pressure drop is a pressure drop of 266 Pa or more.

On the other hand, when it determines with the pressure drop of 266 Pa or more (S10: YES), it progresses to S11 similarly to when it determines with 10 second which is time t1 (S3: YES). In S11, the target value of the feedback control with respect to the vacuum pressure in the reaction chamber 10 is set to the value V1 (refer FIG. 9) which subtracted 266Pa from the present vacuum pressure.

Thereafter, the valve opening degree of the vacuum proportional open / close valve 16 is obtained using the potentiometer 18 (S12). Then, it is judged whether the obtained valve opening degree reaches the set value X1 (S13). At this time, when the valve opening degree reaches the set value X1 (S13: YES), the present vacuum pressure in the reaction chamber 10 is obtained using the vacuum pressure sensors 14 and 15 (S14). Then, it is determined whether the present vacuum pressure in the obtained reaction chamber 10 is equal to or less than the set value X2 (S15). At this time, when the present vacuum pressure in the reaction chamber 10 is greater than the set value (X2) (S15: NO), it is determined that an abnormality has occurred, and when the vacuum pressure change speed control mode (SVAC) is terminated, The process is performed (S16).

On the other hand, when the valve opening degree does not reach the set value X1 (S13: NO), or when the present vacuum pressure in the reaction chamber 10 is equal to or lower than the set value X2 (S15: YES), the reaction chamber ( Regarding the vacuum pressure in 10), the stationary control is performed until a predetermined time (here, 10 seconds) has elapsed from the current vacuum pressure with the target value of the value V1 (see FIG. 9) minus 266 Pa. It performs as (定 値 制 御) (S17). When it is determined that 10 seconds have elapsed since the start of the feedback control (S18: YES), the processing proceeds to execution time processing.

In addition, the process at the time of abnormality of S6 and S16 notifies that the system has an abnormality, and operates the vacuum proportional control valve 16 in a safe direction. In the present embodiment, the vacuum proportional control valve 16 is operated in the closing direction. However, in the system, when the valve is operated in the opening direction, the valve opening degree of development may be maintained. This is because the safety directions are different in the system. Therefore, in abnormal process, what is necessary is just to set so that the valve operation | movement suitable for each system may be performed. In addition, the "notice" includes all things about hearing and the time, and includes notification by a single means (for example, only a beep or the like) or notification by a combination means (for example, a warning sound and a warning indication). Etc.) may be sufficient.

In the execution time process, first, the valve opening degree of the vacuum proportional open / close valve 16 is obtained using the potentiometer 18 (S21). Then, it is determined whether the obtained valve opening degree reaches the set value X1 (S22). At this time, when the valve opening degree reaches the set value X1 (S22: YES), the present vacuum pressure in the reaction chamber 10 is obtained using the vacuum pressure sensors 14 and 15 (S23). Then, it is determined whether the present vacuum pressure in the obtained reaction chamber 10 is equal to or less than the set value X2 (S24). At this time, when the present vacuum pressure in the reaction chamber 10 is larger than the set value X2 (S24: NO), it is determined that an abnormality has occurred, and the vacuum pressure change speed control mode (SVAC) is terminated and the abnormality occurs. The process is performed (S25).

On the other hand, when the valve opening degree does not reach the set value X1 (S22: NO), or when the present vacuum pressure in the reaction chamber 10 is equal to or lower than the set value X2 (S24: YES), the field input or The target vacuum pressure value indicated by the remote input is obtained (S26). In addition, the present vacuum pressure in the reaction chamber 10 is obtained using the vacuum pressure sensors 14 and 15 (S27). Then, it is determined whether the current vacuum pressure in the reaction chamber 10 has reached the target vacuum pressure value (S28). When the present vacuum pressure in the reaction chamber 10 does not reach the target vacuum pressure value (S28: NO), a target vacuum pressure change rate instructed by field input or remote input is obtained (S29).

Further, the current vacuum pressure value in the reaction chamber 10 is obtained by using the vacuum pressure sensors 14 and 15 (S30). The controller 20 generates a vacuum pressure value changed at the target vacuum pressure change rate obtained in S29 with respect to the vacuum pressure value of the current reaction chamber 10 obtained in S30. The internal command is set as the target value of the feedback control, and the target of the feedback control is changed (S31). Thereafter, feedback control is performed (S32).

Specifically, as shown in the block diagram of FIG. 4, the target vacuum pressure value or the vacuum pressure change rate instructed by the site pressure or the remote input is in the range of 0 to 5 V in the interface circuit 21 (see FIG. 1). It is output as a voltage and is input to the internal command generating circuit 111. The internal command generating circuit 111 subtracts a predetermined vacuum pressure value from the current vacuum pressure value of the reaction chamber 10 with respect to the magnitude of the vacuum pressure change rate, and outputs the value as a target value of the feedback control. .

On the other hand, when the present vacuum pressure in the reaction chamber 10 reaches the target vacuum pressure value (S28: YES), the target vacuum pressure value obtained in S26 is set as the target value of the feedback control. Thereafter, feedback control is performed (S32).

Alternatively, feedback control of S32 is continued as long as the operation mode is not changed in the vacuum pressure change speed control mode SVAC.

Here, the case where the abnormality is detected and the abnormality processing is performed will be described with reference to the specific examples shown in FIGS. 11 to 13. FIG. 11: is a figure which shows the state which the abnormality generate | occur | produced in the vacuum pressure sensors 14 and 15. FIG. 12 is a diagram illustrating a state at the time of leakage of the reaction chamber 10. 13 is a view showing a state in which a pipe is blocked.

First, when an abnormality occurs in the vacuum pressure sensors 14 and 15, and as shown in FIG. 11, when the pressure in the reaction chamber 10 does not decrease, the valve of the vacuum proportional opening / closing valve 16 at time t2. The opening degree reaches the set value X1. At this time, the vacuum pressure of the reaction chamber 10 does not become below the set value X2.

As a result, when time t2 has not elapsed 10 seconds from the start of the vacuum pressure change speed control mode SVAC, it is determined that an abnormality has occurred in the system in the processing of S3 to S6 in FIG. 7. And the abnormality process which closed the vacuum proportional opening / closing valve 16 is performed. On the other hand, when the time t2 has passed 10 seconds at the start of the vacuum pressure change speed control mode SVAC, it is determined that an abnormality has occurred in the system in the processing of S13 to S16 in FIG. 7. And the abnormality process which closed the vacuum proportional opening / closing valve 16 is performed.

Next, when a leak occurs in the reaction chamber 10 and the pressure does not decrease during the pressure drop of the reaction chamber 10, as shown in FIG. 12, the vacuum proportional opening / closing valve 16 at time t3. The valve opening degree of reaches the set value (X1). At this time, the vacuum pressure of the reaction chamber 10 does not become below the set value X2.

As a result, when time t3 has not elapsed 10 seconds from the start of the pressure drop in the reaction chamber 10, it is determined that an abnormality has occurred in the system in the processing of S13 to S16 in FIG. 7. And the emergency process which closed the vacuum proportional opening / closing valve 16 is performed. On the other hand, when time t3 has passed 10 second from the pressure drop start of the reaction chamber 10, it is judged that the abnormality has arisen in the system by the process of S22-S25 of FIG. And the abnormality processing which closed the vacuum proportional opening / closing valve 16 is performed.

Finally, when the pipe is clogged and as shown in FIG. 12, when the pressure does not decrease during the pressure drop of the reaction chamber 10, the valve opening degree of the vacuum proportional open / close valve 16 is set at a time t4. X1) is reached. At this time, the vacuum pressure of the reaction chamber 10 does not become below the set value X2.

As a result, when time t4 has not elapsed 10 seconds from the start of the pressure drop in the reaction chamber 10, it is determined that an abnormality has occurred in the system in the processing of S13 to S16 in FIG. 7. And the abnormality process which closed the vacuum proportional opening / closing valve 16 is performed. On the other hand, when time t3 has passed 10 second from the pressure drop start of the reaction chamber 10, it is judged that the abnormality has arisen in the system by the process of S22-S25 of FIG. And the abnormality process which closed the vacuum proportional opening / closing valve 16 is performed.

On the other hand, at the time of normality, as shown in FIG. 9, although the valve opening degree of the vacuum proportional opening-closing valve 16 of time t reaches | attained the setting value X1, the vacuum pressure of the reaction chamber 10 at this time is set. Since it is smaller than the value X2, it is determined that no abnormality has occurred in the system.

Thus, in the vacuum pressure control system which concerns on this embodiment, it is possible to detect abnormality of the system, such as the vacuum pressure sensors 14 and 15, the leak of the reaction chamber 10, or the blockage of piping. When an abnormality is detected, the vacuum proportional opening / closing valve 16 is closed while notifying this. However, it is possible to build a stable pneumatic control system in an emergency.

Alternatively, the set values X1 and X2 set in order to detect the above various abnormalities may be obtained in advance by experiments or the like so that the respective abnormalities can be properly detected.

Here, when using the valve which does not provide the structure (potentiometer 18) which detects a valve opening degree like the vacuum proportional opening / closing valve 16, in order to detect abnormality of a system, instead of using a valve opening degree. The operating voltage input to the valve or the operating air pressure supplied to the valve may be used. Thereby, even if a system is constructed by the valve which does not provide the structure which detects the opening degree of a valve, it is possible to detect abnormality of a system early.

As described above, in the vacuum pressure control system according to the present embodiment, when the controller 20 reaches the preset value X1 of the valve opening degree of the vacuum proportional open / close valve 16, the reaction chamber 10 is described. When the vacuum pressure is larger than the preset value X2, it is determined that an abnormality has occurred in the system. The set values X1 and X2 can be obtained in advance by experiment or the like so that various abnormalities can be properly detected. Therefore, according to the vacuum pressure control system which concerns on this embodiment, it is possible to detect abnormality of the system, such as the vacuum pressure sensors 14 and 15, the leak of the reaction chamber 10, or the blockage of piping. When an abnormality is detected, the vacuum proportional opening / closing valve 16 is closed while notifying this. Therefore, it is possible to construct a high vacuum pressure control system of stability in an emergency.

Or the above embodiment is merely a mere illustration and does not limit all of the present invention, and of course, various improvements and modifications are possible without departing from the gist of the present invention. For example, in the above-described modification, the present invention is exemplified in the case where the present invention is applied to the reaction chamber 10 of the CVD apparatus. However, the present invention can also be applied to vacuum chambers of other semiconductor manufacturing lines. .

Claims (10)

A vacuum proportional on / off valve on the pipe connecting the vacuum vessel and the vacuum pump to change the vacuum pressure in the vacuum vessel by changing the opening degree, a vacuum pressure sensor for measuring the vacuum pressure in the vacuum vessel, and the vacuum pressure sensor A vacuum pressure control system having a controller that controls an opening degree of the vacuum proportional on / off valve based on an output of The controller is configured to set the opening degree of the vacuum proportional opening / closing valve as one point in advance when a vacuum pressure change speed control mode is selected in which the opening degree of the vacuum proportional opening / closing valve is changed to lower the pressure in the vacuum vessel at a predetermined constant speed. And when the output of the vacuum pressure sensor is larger than a predetermined value when a predetermined opening degree is reached, it is determined that an abnormality has occurred in the sealed state of the vacuum container. A vacuum proportional opening / closing valve, a vacuum pressure sensor for measuring the vacuum pressure in the vacuum container by changing the vacuum pressure in the vacuum container by changing the opening degree on a pipe connecting the vacuum container and the vacuum pump, and the vacuum pressure sensor A vacuum pressure control system having a controller that controls an opening degree of the vacuum proportional on / off valve based on an output of The controller opens a predetermined opening degree of the vacuum proportional opening / closing valve when a vacuum pressure change speed control mode is selected in which the opening degree of the vacuum proportional opening / closing valve is changed to lower the pressure in the vacuum vessel at a predetermined constant speed. At one time, when the output of the vacuum pressure sensor is larger than a predetermined value, it is determined that an abnormality has occurred in the system, The controller uses an operating voltage input to the vacuum pressure proportional open / close valve instead of the opening degree of the vacuum proportional open / close valve to detect an abnormality of the system. A vacuum proportional opening / closing valve, a vacuum pressure sensor for measuring the vacuum pressure in the vacuum container by changing the vacuum pressure in the vacuum container by changing the opening degree on a pipe connecting the vacuum container and the vacuum pump, and the vacuum pressure sensor A vacuum pressure control system having a controller that controls an opening degree of the vacuum proportional on / off valve based on an output of The controller opens a predetermined opening degree of the vacuum proportional opening / closing valve when a vacuum pressure change speed control mode is selected in which the opening degree of the vacuum proportional opening / closing valve is changed to lower the pressure in the vacuum vessel at a predetermined constant speed. At one time, when the output of the vacuum pressure sensor is larger than a predetermined value, it is determined that an abnormality has occurred in the system, And the controller uses an operating air pressure supplied to the vacuum pressure proportional open / close valve instead of the opening degree of the vacuum proportional open / close valve to detect an abnormality of the system. A vacuum proportional opening / closing valve, a vacuum pressure sensor for measuring the vacuum pressure in the vacuum container by changing the vacuum pressure in the vacuum container by changing the opening degree on a pipe connecting the vacuum container and the vacuum pump, and the vacuum pressure sensor A vacuum pressure control system having a controller that controls an opening degree of the vacuum proportional on / off valve based on an output of The controller opens a predetermined opening degree of the vacuum proportional opening / closing valve when a vacuum pressure change speed control mode is selected in which the opening degree of the vacuum proportional opening / closing valve is changed to lower the pressure in the vacuum vessel at a predetermined constant speed. At one time, when the output of the vacuum pressure sensor is larger than a predetermined value, it is determined that an abnormality has occurred in the system, The controller detects an abnormality in the system or notifies the controller when it determines that an abnormality has occurred in the system. A vacuum proportional opening / closing valve, a vacuum pressure sensor for measuring the vacuum pressure in the vacuum container by changing the vacuum pressure in the vacuum container by changing the opening degree on a pipe connecting the vacuum container and the vacuum pump, and the vacuum pressure sensor A vacuum pressure control system having a controller that controls an opening degree of the vacuum proportional on / off valve based on an output of The controller opens a predetermined opening degree of the vacuum proportional opening / closing valve when a vacuum pressure change speed control mode is selected in which the opening degree of the vacuum proportional opening / closing valve is changed to lower the pressure in the vacuum vessel at a predetermined constant speed. At one time, when the output of the vacuum pressure sensor is larger than a predetermined value, it is determined that an abnormality has occurred in the system, And the controller operates the vacuum proportional opening / closing valve in a safe direction of the system when detecting the abnormality of the system or determining that the abnormality is occurring in the system. delete delete delete delete delete

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