JPH0799481B2 - Semiconductor wafer processing method and processing apparatus used in the method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a technique effectively applied to a control technique and further a feedback control technique. For example, it is used for a semiconductor integrated circuit manufacturing technique such as dry etching. It is related to effective technology.

[Conventional technology]

For example, in the manufacture of semiconductor integrated circuits, wafer processing using a reaction chamber that provides a predetermined atmosphere, such as dry etching and CVD (chemical vapor deposition), has a large weight. Therefore, in the method or apparatus for manufacturing a semiconductor integrated circuit, it is important to control the atmosphere in the reaction chamber with high accuracy and efficiency.

Particularly recently, for example, Nikkei McGraw-Hill's "Nikkei Microdevice December 1985 issue (No.6)" 185-101.
As described in the pages, etc., the diameter of the semiconductor wafer, which is the base material of the semiconductor integrated circuit, has been increasing. The single-wafer method, in which the wafers are placed one by one in the reaction chamber, has become advantageous in terms of high-precision processing, rationalization of wafer handling, downsizing of equipment, and the like.

However, in the single-wafer method, since the wafers are placed in the reaction chamber one by one and subjected to the processing, the atmosphere in the reaction chamber after the wafers are loaded into the reaction chamber is longer than the actual processing time in which the processing is performed in the reaction chamber. However, the waiting time until the actual processing becomes possible after reaching the predetermined condition takes a long time, which is a great obstacle to the efficient operation of the single wafer type.

Therefore, the present inventor studied a control technique for improving the efficiency of the above-mentioned single-wafer processing, for example. The following is a technology which has not been publicly known but which has been studied by the present inventor, and the outline thereof is as follows.

FIG. 13 shows an example in which the control technique studied by the present inventor is applied to a semiconductor integrated circuit manufacturing apparatus.

The semiconductor integrated circuit manufacturing apparatus shown in the figure is configured as a dry etching apparatus using reactive ions. This apparatus has, as the controlled system 1, a reaction chamber 11 having an air supply system and an exhaust system. The inside of the reaction chamber 11 is configured such that the reactive gas 12 is supplied by the air supply system and is evacuated by the exhaust system. A vacuum exhaust pump 14 is provided as an exhaust system. A pressure control valve 13 is interposed between the vacuum exhaust pump 14 and the reaction chamber 11.
By operating the opening degree of the valve 13, the pressure in the reaction chamber 11 is variably adjusted. Further, the reaction chamber 11 is provided with a high frequency applying device 15 for ion-activating the gas 12 inside.

Along with the controlled system 1 described above, a control device 3 for setting the atmospheric pressure (control amount) in the reaction chamber 11 detected by the pressure sensor 2 to a predetermined target value Vi is provided. This control device 3 is composed of a feedback control device 31, a servo drive device 32, a potentiometer 33, etc., and controls the pressure control valve 13 so that the pressure value in the reaction chamber 11, that is, the control amount Vf, becomes equal to the target value Vi. The opening is continuously variable.

In this case, the feedback control device 31 is composed of a subtracter and an output amplifier, and is a control output or an operation amount that makes the difference (Vf−Vi) between the control amount Vf and the target value Vi zero.
Output Vox. The servo drive device 32 servo-drives the valve 13 so that the opening of the pressure control valve 13 detected by the potentiometer 33 follows the operation amount Vox.

Here, the control device 3 is configured to control the start and stop of its operation by a control start / stop command C given from the outside. This command C is activated (C = 1) when processing is performed in the reaction chamber 11. This activation starts the control described above. In addition, when performing a setup process such as wafer replacement, deactivation (C =
0) is done. When this is inactive, the control by the control device 3 is stopped. Therefore, when a large number of wafers are divided and processed individually, the command C is active (C =
1) and inactive (C = 0) are repeated alternately.

As described above, the semiconductor integrated circuit manufacturing apparatus capable of processing a large number of semiconductor wafers one by one is constructed.

[Problems to be solved by the invention]

However, the present inventor has clarified that the above-described technique has the following problems.

That is, for example, in the control technique applied to the semiconductor integrated circuit manufacturing apparatus described above, the controlled variable Vf of the controlled system 1 is controlled by negative feedback. This feedback control is not so problematic when the control system is in a sufficiently stable steady state. However, in this feedback control, as shown in FIG. 14, the manipulated variable Vox may become excessive or excessively small for a while after the feedback control is started due to transmission delay or inertia in the control system. ,
As a result, the overshoot (+ Δ) at which the control amount Vf passes the target value Vi and this overshoot + Δ
An unstable state occurs in which an undershoot (-Δ) that excessively corrects is generated.

Therefore, for example, in the above-described semiconductor integrated circuit manufacturing apparatus, after the wafer is loaded into the reaction chamber 11 and the control is started, that is, after the command C is changed from 0 to 1, the atmosphere state in the reaction chamber 11 is changed. While it stabilizes near the target value Vi,
Requires a considerable waiting time ts. During this waiting time ts, of course, processing cannot be performed. Therefore, it was made clear by the inventor of the present invention that the waiting time ts is a major impediment factor for reducing the overall processing efficiency in the single wafer processing method in which a large number of semiconductor wafers are processed one by one.

Further, in feedback control, an overshoot (+ Δ) in which the control amount Vf greatly exceeds the target value Vi is unavoidable due to excessive operation at the start of the control, but this overshoot (+ Δ) may cause various adverse effects. May bring. For example, when the controlled variable Vf is a temperature and the temperature is to be controlled to a target value Vi that is close to the maximum temperature allowed for the object to be processed, the overshoot (+ Δ) causes an allowable limit for the object to be processed. The temperature is exceeded.

An object of the present invention is to reduce the waiting time from the start of control until the control system stabilizes,
It is an object of the present invention to provide a technique relating to a control method and a device capable of suppressing overshoot caused by an excessive amount of operation.

Further, the present invention relates to a method of processing a semiconductor wafer and a processing apparatus therefor capable of improving the efficiency of a single-wafer-type semiconductor integrated circuit manufacturing process in which a large number of semiconductor wafers are processed one by one by utilizing the control technology. To provide the technology.

The above and other objects and novel characteristics of the present invention are
It will be apparent from the description of the present specification and the accompanying drawings.

[Means for solving problems]

The outline of a typical one of the inventions disclosed in the present application will be briefly described as follows.

That is, prior to the start of feedback control, the controlled system is given an operation amount of such a magnitude as to balance the controlled variable of the controlled system near the target value for a certain period of time.

[Action]

According to the above-mentioned means, the control amount of the controlled system is preliminarily operated by the operation amount given in advance to the vicinity of the target value. If feedback control is performed after this, the control amount has already roughly reached the target value and the difference between the control amount and the target value has become small, so the operation amount by the feedback control will not be in an excessive excess state. Absent. This achieves the purpose of shortening the waiting time from the start of control until the control system becomes stable, and suppressing the overshoot caused by the excessive operation amount.

〔Example〕

Preferred embodiments of the present invention will be described below with reference to the drawings.

In each drawing, the same reference numerals indicate the same or corresponding parts.

FIG. 1 shows an embodiment of a control system to which the control device according to the present invention is applied.

The control system shown in FIG. 1 includes a controlled system 1, a sensor 2, a feedback control device 31, a switching means 4, and a storage device.
It is composed of a RAM (random access memory) 53, a timer 54, etc., and is configured so that the start / stop of the entire operation is instructed by a control start / stop command C given from the outside.

Here, the feedback control device 3 outputs an operation amount Vo1 such that the control amount Vf fed back from the controlled system 1 by the sensor 2 becomes equal to the target value Vi.

The sensor 2 detects a controlled variable Vf such as pressure (vacuum degree) and temperature in the controlled system 1.

The RAM 53 stores the manipulated variable Vo2 having such a magnitude that the controlled variable Vf of the controlled system 1 is continuously converged and balanced to the target value Vi. The stored operation amount Vo2 of the RAM 53 is the feedback control device 3
When the control by is in a stable state, sampling is performed from the manipulated variable Vo1 (Vox) output from the feedback control device 3. In this case, the sampling timing is appropriate when the feedback control state is most stable. In such a case, in the case of the embodiment, the command C is 1 to 0.
The timing immediately before the control operation is stopped by switching to is selected.

The switching means 4 selects one of the operation amount Vo1 output from the feedback control device 3 and the operation amount Vo2 read from the RAM 53, and the selected operation amount Vox (Vo1 or Vo2) is supplied to the controlled system 1. give. The switching means 4 is switched and controlled by the timer control means. This timer control means is composed of a timer 54.

As for the timer 54, the control start / stop command C is active (C = 1)
When it becomes, it starts and measures ts for a fixed time. The switching means 4 has a fixed time after the timer 54 is activated.
Until the ts is activated, the B side, that is, the control output (operation amount Vo1) of the feedback device 31 is selected, and when the measurement of the fixed time ts ends, the A side, that is, the storage output of the RAM 53 (the operation amount V1).
o2) is selected and given to the controlled system 1.

Next, an example of a control method executed by the above-described control device will be described.

That is, in the control device shown in FIG. 1, the operation amount Vox to the controlled system 1 is feedback-controlled so that the control amount Vf of the controlled system 1 becomes equal to the target value Vi, and this feedback control is started. Before that, a preliminary step is performed in which the controlled system 1 is provided with a constant manipulated variable Vo2 such that the controlled variable Vf converges to the target value Vi and is balanced for a predetermined time ts.

FIG. 3 is a flowchart showing an embodiment of a control method implemented by the control system shown in FIG.

In the flowchart of FIG. 3, in step S1, the control start / stop command C from the outside waits for 0 to 1. When the command C changes from 0 to 1, the control operation is started. Then, first, through steps S2 and S3, RA
The manipulated variable Vo2 stored in M53 is given to the controlled system 1 as the actual manipulated variable Vox for a fixed time ts. When the fixed time ts elapses, the manipulated variable Vo1 by the feedback control becomes the actual manipulated variable Vox as the controlled system 1 in steps S4 and S5.
Will be given for a fixed time ts. That is, feedback control is performed at this stage. This feedback control state is maintained until the command C becomes zero. When the command C changes from 1 to 0, the current operation amount Vox, that is, the feedback control output (operation amount Vo1) in this case is sampled in step S6. This sampled operation amount is stored in the RAM 53 as a new storage operation amount Vo2.
Stored in. The manipulated variable Vo2 stored at this time is used in steps S2 and S3 to be restarted next. Step S6
After that, the process proceeds to step S7, and the entire control operation is stopped. Then, the process returns to step S1 and waits until the command C becomes 1 again.

FIG. 4 is a waveform chart showing an example of the control operation realized by the technique described above.

As shown in FIG. 4, before the feedback control is started, if the manipulated variable Vo2 for balancing the controlled variable Vf of the controlled system 1 near the target value Vi is given to the controlled system 1 for a certain time ts, As a result, the controlled variable Vf of the controlled system 1 becomes equal to the target value Vi.
Preliminary operation is performed up to the vicinity. If feedback control is performed after this, the control amount Vf has already roughly reached the target value Vi and the difference between the control amount Vf and the target value Vi has become small, so the manipulated variable Vo1 by the feedback control is extremely excessive. Or it won't be too small. Δt represents the time from the end of the preliminary process described above until the control system stabilizes, and this time Δt can be made extremely short by the preliminary process described above.

As described above, the waiting time ts from the start of control to the stabilization of the control system is shortened. At the same time, it becomes possible to suppress the overshoot caused by the excessive operation amount.

Therefore, for example, if the above-described control technique is applied to the single-wafer type semiconductor integrated circuit manufacturing technique, the waiting time ts generated every time one semiconductor wafer is processed can be shortened,
This makes it possible to significantly improve the overall processing efficiency.

2, 5 and 6 show a further preferred embodiment of the control technique according to the invention. In this case, FIG. 2 shows an embodiment of a control system to which the control device according to the present invention is applied. FIG. 5 is a flowchart showing an embodiment of a control method implemented by the control system shown in FIG. FIG. 6 is a waveform chart showing an example of the control operation realized by the technique of this embodiment.

Explaining the difference from the technique of the above-mentioned embodiment,
In the technique of this embodiment, a front-end process including steps S1-1 and S1-2 is newly provided between steps S1 and S2 in the flowchart of FIG. This step S1-1, S1-
In 2, the control amount is set prior to the preliminary process in step S1.
An excessive manipulated variable Vo3 (Vo3 >> Vo2) that converges and balances in a direction in which Vf greatly exceeds the target value Vi is given to the controlled system 1 for a short time t2.

In order to implement such a method, in the control system shown in FIG. 2, a second timer 56, a second switching means 41, and a setting means 57 are newly added. These are the excessive operation amount Vo3 set in advance and the stored operation amount Vo3 of the RAM53.
It serves as a second timer control means for providing the controlled system 1 with the constant time t2 before the 2 is provided to the controlled system 1. The excessive manipulated variable Vo3 is arbitrarily set by the setting means 57. In this case, the manipulated variable Vo3 and the time t2 are set so that the controlled variable Vf does not exceed the target value Vi.

As a result, as shown in FIG. 6, the control amount Vf is equal to the command C.
During the first timer control time t2 after the control becomes 1 and the control is started, the target value Vi is rapidly changed. As a result, the waiting time ts from the start of control to the stabilization of the control system is further shortened.

Therefore, if the control technique of this embodiment is applied to, for example, the above-mentioned single-wafer-type semiconductor integrated circuit manufacturing technique, the waiting time ts generated each time one semiconductor wafer is processed can be further shortened. The processing efficiency of can be further improved.

7 and 8 show an embodiment in which the control technique described above is applied to a method and an apparatus for manufacturing a semiconductor integrated circuit.

First, FIG. 7 shows an embodiment of a semiconductor integrated circuit manufacturing apparatus using the technique of the embodiment shown in FIG.

The semiconductor integrated circuit manufacturing apparatus shown in the figure is configured as a dry etching apparatus using reactive ions. This apparatus has, as the controlled system 1, a reaction chamber 11 having an air supply system and an exhaust system. The inside of the reaction chamber 11 is configured such that the reactive gas 12 is supplied by the air supply system and is evacuated by the exhaust system. A vacuum exhaust pump 14 is provided as an exhaust system. A pressure control valve 13 is interposed between the vacuum exhaust pump 14 and the reaction chamber 11.
By operating the opening degree of the valve 13, the pressure in the reaction chamber 11 is variably adjusted. Further, the reaction chamber 11 is provided with a high frequency applying device 15 for ion-activating the gas 12 inside.

Along with the controlled system 1 described above, a control device 3 for setting the atmospheric pressure (control amount) in the reaction chamber 11 detected by the pressure sensor 2 to a predetermined target value Vi is provided. The control device 3 is provided with a feedback control device 31, a servo drive device 32, a potentiometer 33, a switching means 4 and the like, as well as a control unit 5 including a timer control means and an operation amount storage means.

The feedback control device 31 is composed of a subtractor and an output amplifier, and outputs a control output that makes the difference (Vf-Vi) between the control amount Vf and the target value Vi (Vf-Vi) zero, that is, the manipulated variable Vo1.

The servo drive device 32 is a part of the controlled system 1 and functions as an operating means for varying the pressure (vacuum degree) in the reaction chamber 11. This servo drive device 32 includes a pressure control valve 13 detected by a potentiometer 33.
So that the opening of the valve follows the above-mentioned manipulated variable Vox.
Servo 3

The control unit 5 includes a general-purpose information processing device (CPU) 51, which is a semiconductor integrated circuit, and a system ROM (read-only storage device).
52, RAM 53, timer 54, input / output port (I / O) 55, etc. This control unit 5 is a system RO
By the program written in M52, the storage means for storing the manipulated variable Vo1 when the control by the feedback control device 31 is in a stable equilibrium state, and the control operation by the feedback control device 31 for a fixed time t1 from the start of control are performed. And a timer control means for stopping and supplying the operation amount Vo2 stored in the RAM 53 to the operation means.

The switching means 4 includes an operation amount Vo1 output from the feedback control device 3 and an operation amount Vo2 output from the control unit 5.
Select either one of. Selected manipulated variable Vox (Vo1
Alternatively, Vo2) is given to the servo drive device 32.
The switching means 4 is switched and controlled by the timer control means by the control unit 5. This timer control means operates based on the time t1 of the built-in timer 54.

Further, the entire control device 3 is configured so that the start and stop of its operation are controlled by a control start / stop command C given from the outside. This command C is the reaction chamber
It is activated (C = 1) when performing the processing within 11. This activation starts the control described above. Further, it is deactivated (C = 0) when performing a setup process such as wafer replacement. When this is inactive, the control by the control device 3 is stopped. Therefore, in the case of processing a large number of wafers one by one, the command C alternately repeats active (C = 1) and inactive (C = 0).

As described above, the semiconductor integrated circuit manufacturing apparatus capable of processing a large number of semiconductor wafers one by one is constructed.

FIG. 8 is a flowchart showing one embodiment of a method for manufacturing a semiconductor integrated circuit implemented by using the semiconductor integrated circuit device described above.

As shown in the figure, in the manufacturing method of this embodiment, a pre-process of loading a semiconductor wafer into the reaction chamber (step S8)
And this step of processing the semiconductor wafer in the reaction chamber while feedback-controlling the atmosphere in the reaction chamber (step S4
To S7) and the post-process (S8) for taking out the processed semiconductor wafer from the reaction chamber are sequentially repeated to process a large number of semiconductor wafers.

Along with this, a sampling step (S6) in which the operation amount given by the feedback control is stored immediately before the completion of the main step, and the above step is performed before the feedback control of the atmosphere in the next main step is started. A preliminary step (S2, S2-1, S3) of operating the atmosphere for a fixed time t1 is performed according to the stored operation amount.

Through the series of steps described above, the waiting time ts until the atmospheric conditions in the reaction chamber 11 are stabilized is shortened, and a large number of semiconductor wafers can be processed one by one with high efficiency. ing.

FIG. 9 shows a further preferred embodiment of a semiconductor integrated circuit device to which the control technique according to the present invention is applied.

The semiconductor integrated circuit manufacturing apparatus shown in the figure uses the control technology shown in FIGS. This semiconductor integrated circuit manufacturing apparatus is provided with a second timer control means in addition to the configuration shown in FIG. The second timer means controls the excess operation amount Vo3 preset by the timer 56 built in the control unit 5 into the RAM.
Before the operation amount Vo2 from 53 is applied to the operation means, the operation quantity Vo2 is applied to the operation means for a fixed time t2. The operation amount Vo3 is arbitrarily set by the setting means 57 such as a key input device. In this case, the manipulated variable Vo
3 and time t2 are set so that the controlled variable Vf surely remains below the target value Vi.

FIG. 10 is a flowchart showing an embodiment of a method for manufacturing a semiconductor integrated circuit, which is carried out by the apparatus shown in FIG.

Explaining the differences between the embodiment shown in FIG. 10 and the embodiment shown in FIG. 8, the method of the embodiment shown in FIG.
Between the steps S1 and S2 in the flow chart of FIG. 8, a pre-process by steps S1-1 and S1-2 is newly placed. In steps S1-1 and S1-2, prior to the preliminary process in step S1, an excessive manipulated variable Vo3 (V
o3 >> Vo2) is applied to the controlled system 1 for a short time t2.

As a result, the control amount Vf is rapidly changed toward the target value Vi during the first timer control time t2 after the command C becomes 1 and the control is started. As a result, the waiting time ts from the start of control to the stabilization of the control system is further shortened. Therefore,
According to the method of this embodiment, the waiting time ts that occurs each time one semiconductor wafer is processed can be further shortened, and thus the overall processing efficiency can be further improved.

FIG. 11 shows an embodiment in which the control technique according to the present invention is applied to temperature control.

In the semiconductor integrated circuit manufacturing apparatus shown in FIG. 9, the pressure (vacuum degree) in the reaction chamber 11 is controlled, but here, the temperature in the reaction chamber 11 is controlled. The difference from the one shown in FIG. 9 is that a heater 13, a power controller 32, and a power source 14 are used as a means for controlling the temperature in the reaction chamber 11. In addition, the controlled system 1
The temperature sensor 2 is used as a means for detecting the controlled variable Vf.

As described above, the control technique according to the present invention can be applied to the case of controlling the atmospheric conditions such as temperature.

Further, as shown in FIGS. 12 (a) and 12 (b), the control technique according to the present invention can also be applied to multi-step control in which the control target value Vi such as pressure is changed stepwise depending on the time zone.

In the same figure, (a) shows an operation example when the control technique according to the present invention is applied, and (b) shows an operation example when the control technique according to the present invention is not applied, with waveform charts corresponding to each other.

In this case, each time the target value Vi (Vi1, Vi2, Vi3) is updated, the above-described preliminary process and, if necessary, the above-described front-end process are performed, so that the target value Vi with the updated control amount Vf is obtained.
Waiting time ts until convergence to (Vi1, Vi2, Vi3) and stabilization
Can be shortened, and the overshoot that occurs each time the target value Vi is updated can be suppressed.

This multi-step step control can be applied to the above-described semiconductor integrated circuit manufacturing method and manufacturing apparatus, of course.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. There is no end. For example, RAM5 above
Instead of 2, mechanical storage means using a potentiometer 33 or the like may be used.

In the above description, the case where the invention made by the present inventor is mainly applied to the semiconductor integrated circuit manufacturing technology such as dry etching which is the field of application which is the background has been described, but the invention is not limited thereto, and, for example,
It can also be applied to technology for controlling the culture environment of microorganisms.

〔The invention's effect〕

The following is a brief description of an effect obtained by the representative one of the inventions disclosed in the present application.

(1) Before the feedback control is started, the control system is controlled after the control is started by giving the controlled system an operation amount for balancing the control amount of the controlled system near the target value for a certain period of time. The effect is to reduce the waiting time until the temperature becomes stable.

(2) Further, there is an effect of suppressing an overshoot caused by an excessive control operation amount.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a control device to which the control technique according to the present invention is applied, and FIG. 2 is a diagram showing a second embodiment of a control device to which the control technique according to the present invention is applied. FIG. 4 is a flow chart showing a first embodiment of a control method implemented by the device shown in FIG. 1, FIG. 4 is a waveform chart showing an operation example of the device shown in FIG. 1, and FIG. FIG. 6 is a flow chart showing a second embodiment of the control method implemented by the device shown in FIG. 6, FIG. 6 is a waveform chart showing an operation example of the device shown in FIG. 2, and FIG. 7 is a control device shown in FIG. FIG. 8 is a diagram showing a first embodiment of a semiconductor integrated circuit manufacturing apparatus configured by using FIG. 8, FIG. 8 is a flowchart showing a first embodiment of a semiconductor integrated circuit manufacturing method performed by the apparatus shown in FIG. 7, FIG. 9 shows a construction using the control device shown in FIG. Showing a second embodiment of the semiconductor integrated circuit manufacturing apparatus, FIG. 10 is a flow chart showing the second embodiment of the semiconductor integrated circuit manufacturing method carried out by the apparatus shown in FIG. 9, and FIG. The figure which shows the example which applied the control technology by this invention to temperature control, Figure 12 (a) (b) shows the respective operational example when the control technology by this invention is applied to multi-step control and when it is not. Waveform chart, FIG. 13 is a diagram showing a configuration of a semiconductor integrated circuit manufacturing apparatus examined prior to the present invention, and FIG. 14 is a waveform chart showing an operation example of the semiconductor integrated circuit manufacturing apparatus shown in FIG. . 1 ... Controlled system, 2 ... Sensor, 3 ... Control device, 31
...... Feedback control device, 4 …… Switching means, 53 ……
Storage device (RAM), 54, 56 ... Timer, 57 ... Setting means, Vo1, Vo2, Vo3 ... Operation amount, Vf ... Control amount, Vi ... Target value, 5 ... Control unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Nakata 111 Nishiyokote-cho, Takasaki City, Gunma Prefecture Takasaki Plant, Hitachi, Ltd. (56) References JP-A-53-101726 (JP, A) JP-A-58 -130529 (JP, A) JP 58-11641 (JP, B2)

Claims (4)

[Claims] 1. A pre-process of loading a semiconductor wafer into a reaction chamber, a main process of processing a semiconductor wafer in the reaction chamber while feedback-controlling an atmosphere in the reaction chamber, and a post-treatment of the processed semiconductor wafer from the reaction chamber. A method of manufacturing a semiconductor integrated circuit in which a large number of semiconductor wafers are processed by sequentially repeating the steps, a sampling step of storing an operation amount given by feedback control immediately before the completion of the present step, and the reaction chamber. Before the feedback control of the atmosphere in the next main step of (1) is started, a preliminary step of operating the atmosphere in the reaction chamber for a fixed time by the operation amount stored in the sampling step is performed. Semiconductor wafer processing method. 2. A semiconductor integrated circuit manufacturing apparatus having a reaction chamber in which a semiconductor wafer is inserted and an atmospheric pressure is feedback-controlled, and an operating means for adjusting the pressure in the reaction chamber, wherein the pressure in the reaction chamber is A feedback control device that outputs an operation amount that is equal to a target value to the operation means, a storage device that stores the operation amount when the control by the feedback control device is in a stable equilibrium state, and a constant amount from the start of control. A semiconductor wafer processing apparatus comprising: a timer control means for stopping the control operation by the feedback control device for a period of time and giving the operation amount stored in the storage means to the operation means. 3. A second timer control means for giving a preset operation amount to the operating means for a fixed time before the stored operation amount of the storage device is given to the operating means. The semiconductor wafer processing apparatus according to claim 2, wherein 4. The operating means is constituted by a servo drive device for feedback-controlling the opening of a pressure control valve provided in the exhaust system of the reaction chamber. Alternatively, the semiconductor wafer processing apparatus according to item 3.