JPH06104909B2 - Dry process treatment method and apparatus thereof - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a dry process processing method such as a dry etching processing apparatus and an apparatus thereof.

[Background of the Invention]

The pressure control mechanism of a conventional dry process treatment apparatus is constructed as shown in FIG. That is, this pressure control mechanism is configured to keep both the flow rate of the processing gas and the pressure of the processing chamber constant.

The gas flow rate control unit 2 for keeping the gas flow rate constant includes a gas source 9, an opening / closing valve 8, a gas flow rate sensor 5, a control valve 3, a control valve drive unit 4, a servo amplifier 6, and a flow rate setting unit 7. The gas flow rate is detected by the flow rate sensor 5, the difference between the flow rate and the value set by the flow rate setting unit 7 is amplified by the servo amplifier 6, and the control valve 3 is moved via the control valve drive unit 4 to obtain a constant gas flow rate. I try to keep

The pressure control unit 10 of the processing chamber 1 includes a pressure sensor 11, an exhaust conductance control valve 12, and a valve drive unit.
13, a servo amplifier 14, a pressure setting unit 15, and a vacuum exhaust device 16.

The pressure control detects the pressure in the processing chamber 1 with the pressure sensor 11, the difference with the value set in the pressure setting unit 15 is amplified by the servo amplifier 14, and the conductance of the control valve 12 is increased via the valve driving unit 13. This is performed by changing the exhaust capacity of the exhaust device 16 by changing it.

In the exhaust control unit 10, when the control valve 12 is changed, the pressure is the volume of the processing chamber 1 and the gas inflow amount,
It gradually changes depending on the displacement. Therefore, if the valve is opened and closed according to the difference between the measured pressure and the set pressure, this pressure control system vibrates and the pressure cannot be controlled stably. Therefore, the response of the servo amplifier 14 is delayed so that the pressure can be controlled stably.

In order to perform the process with good reproducibility in the dry process device, it is necessary to perform the process under constant process conditions, that is, the gas flow rate and gas pressure.

However, in the conventional pressure control method, it takes time until the pressure becomes constant, which is a bottleneck in improving the processing capacity of the dry process device.

Particularly, in the conventional pressure control method, it takes about 1 minute to reach the set pressure, and the ratio to the entire processing time is set to 20 to 30% as the dry process speed increases. Therefore, it is essential to shorten the gas pressure control time to improve the processing capacity.

[Object of the Invention]

An object of the present invention is to provide a dry process treatment apparatus capable of enhancing control response of dry process treatment pressure and improving treatment capacity.

[Outline of Invention]

That is, the present invention is, in a dry process apparatus, a gas supply means for supplying a processing gas into the processing chamber, an exhaust means for exhausting the processing chamber, a pressure detection means for detecting the pressure in the processing chamber, and a gas of the gas supply means. And a control means for stepwise controlling at least one of the flow rate and the exhaust amount of the exhaust means by a predetermined pattern to set and maintain the predetermined pressure in the processing chamber. At, when setting the predetermined pressure in the processing chamber,
First, the flow rate of the processing gas supplied into the processing chamber is set to a predetermined flow rate by gradually decreasing from a flow rate higher than the normal flow rate when processing the sample, or the exhaust volume of the processing chamber is processed to process the sample. At this time, the process chamber is brought closer to a predetermined pressure by controlling the exhaust amount smaller than the normal exhaust amount to be gradually increased from the normal exhaust amount to set the predetermined exhaust amount. It is characterized in that at least one of the flow rate and the exhaust amount is controlled according to the difference between the pressure and a preset value to set and maintain the predetermined pressure in the processing chamber.

Example of Invention

 FIG. 2 shows an embodiment according to the present invention, which will be described below.

A gas supply pipe 22 for supplying a processing gas and an exhaust pipe 32 for exhausting the inside of the processing chamber are provided in the processing chamber 20 for performing the dry process.

The gas supply unit includes a gas source 31, an opening / closing valve 30, a flow sensor 27,
Consists of a control valve 23.

The signal of the flow rate sensor 27 is sent to the microcomputer 21 via the A / D converter 28. The control valve 23 is driven by a drive motor 24, an encoder 25 is connected to the motor, and the signal of the encoder 25 is sent to the microcomputer 21.

The drive motor 24 is driven by a driver 26 controlled by the microcomputer 21.

The gas flow rate is set by sending a setting signal from the flow rate setting unit 29 to the microcomputer 21.

The exhaust unit is composed of a conductance control valve 33 and a vacuum exhaust device 40.

The control valve 33 is driven by the drive motor 34,
An encoder 35 is connected to the motor, and its signal is sent to the microcomputer 21.

The drive motor 34 is driven by a driver 36 controlled by the microcomputer 21.

The signal from the pressure sensor 37 installed in the processing chamber 20 is sent to the A / D converter 38.
Is sent to the microcomputer 21 via. The gas pressure is set by sending a setting signal from the pressure setting unit 39 to the microcomputer 21.

The operation of each part during pressure control in the above configuration will be described below.

In the processing chamber 20, the control valve 33 is fully opened to exhaust the processing chamber to a low pressure. An object to be processed (not shown) is carried into the processing chamber 20 by a transfer system (not shown). When the completion of loading is detected, the pressure control valve 33 is closed and the gas flow rate control valve 23 for gas supply is fully opened as shown in FIG. When the processing gas is a gas mixture of two or more kinds of raw material gases, the mixing ratio of the respective raw material gases to be supplied is not changed, and one of them is the maximum supply amount of the control valve of the gas supply unit. Control by the microcomputer 21. At this time, the pressure approaches the set pressure within a few seconds, although it varies depending on the processing conditions. In the microcomputer 21, the rotation angles of the valve drive motors 24, 34 with respect to the set conditions at the time of the previous processing are stored in the memory by the signals from the encoders 25, 35. The pressure inside the processing chamber is checked by the pressure sensor 37, and when the pressure falls within ± 20% of the set pressure, the pressure and the opening / closing rate of the gas flow rate control valve are memorized via the drivers 26 and 36 by the instruction of the microcomputer 21. Fixed to the state stored in.

Further, when the pressure in the processing chamber reaches ± 10% of the set pressure, the control valves 23 and 33 are controlled by a conventional method in which the control is performed according to the difference between the set pressure and the pressure in the processing chamber. Next, read the open / close ratio of the control valve from the encoders 25 and 35 when the processing chamber was at ± 3% of the set pressure for 1 minute, clear the memory that stores the open / close ratio of the valve in the microcomputer, and use the new data. Write.

As described above, in the pressure control method according to the present invention, the inflow gas amount is first maximized and the exhaust valve is closed. Therefore, the pressure rises in the shortest time, and when the pressure is close to the set pressure, the open / close ratio of the valve valve is set to the set pressure. Since there is a state in which the pressure is held, there is no problem of pressure overshooting and vibration as in the conventional method.

In the present embodiment described above, the set pressure can be reached in about 10 seconds, and the time can be shortened to about 1/6 of the conventional time.

Further, in this embodiment, the pressure control method until the processing is started has been described, but the same can be applied to the case where the processing conditions such as the gas flow rate, the gas line and the gas pressure are changed in the middle. Even in that case, the control valve opening / closing ratio under the processing condition after the midway change is stored, and when the changed pressure condition is high, the method described in the present example is used. Conversely, when the changed pressure condition is low, the reverse operation is performed. Similarly, the gas supply can be stopped and the exhaust valve can be fully opened to approach the set pressure in the same manner.

Further, in the present embodiment, the example in which the pressure control is performed by opening and closing the control valve has been described, but it is clear that basically the same method can be performed as long as it is an exhaust method capable of changing the exhaust amount. For example, when the pressure is controlled by evacuating with a mechanical vacuum exhaust pump and changing the exhaust amount according to the rotation speed of the vacuum pump, the rotation speed under each processing condition can be stored and controlled.

〔The invention's effect〕

As described above, according to the present invention, the time from when the object to be processed is put into the processing chamber to when the processing chamber is set to a predetermined pressure can be shortened as compared with the method using the conventional apparatus. ,, now it is possible to improve the processing capacity of dry process equipment.

[Brief description of drawings]

FIG. 1 is a diagram showing a pressure control system in a conventional dry process device, FIG. 2 is a diagram showing an embodiment of a pressure control system in the dry process device of the present invention, and FIG. 3 is a diagram showing a dry process device of the present invention. It is the figure which showed the pressure control flow. 20 …… Processing chamber, 21 …… Microcomputer, 23 …… Control valve, 25 …… Encoder, 27 …… Flow sensor, 33 …… Control valve, 35 …… Encoder, 37
...... Pressure sensor, 40 ...... vacuum exhaust device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Uemura Inventor Takashi Uemura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Hitachi, Ltd. Institute of Industrial Science (72) Inventor Susumu Aiuchi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Banchi Co., Ltd. Hitachi, Ltd., Production Engineering Laboratory

Claims (5)

[Claims] 1. A dry process apparatus for processing a sample in a processing chamber set to a predetermined pressure, comprising gas supply means for supplying a processing gas into the processing chamber, and exhaust means for exhausting the processing chamber. The pressure detection means for detecting the pressure in the processing chamber, and at least one of the gas flow rate of the gas supply means and the exhaust amount of the exhaust means are controlled stepwise according to a predetermined pattern to set the predetermined inside of the processing chamber. And a control means for setting and maintaining the pressure of the dry process apparatus. 2. A dry process method for processing a sample in a processing chamber set to a predetermined pressure, wherein when the processing chamber is set to a predetermined pressure, first, a flow rate of a processing gas supplied into the processing chamber is set. The flow rate that is higher than the normal flow rate when processing the sample is gradually reduced to a predetermined flow rate, or the exhaust volume that exhausts the processing chamber is smaller than the normal exhaust volume when processing the sample. The process chamber is brought closer to the predetermined pressure by increasing the exhaust amount stepwise and setting it to a predetermined exhaust amount, or by performing at least one control, and then the pressure inside the process chamber is set in advance. The dry process method is characterized in that at least one of the flow rate and the exhaust amount is controlled in accordance with the difference with the above value to set and maintain the predetermined pressure in the processing chamber. 3. In the control for gradually reducing the flow rate of the processing gas to set a predetermined flow rate, first, the pressure in the processing chamber falls within a first predetermined range with respect to the predetermined pressure. Until the flow rate of the processing gas is set to a first flow rate that is higher than the normal flow rate when processing the sample, and then, after the pressure in the processing chamber enters the first predetermined range, The dry process method according to claim 2, wherein the dry process method is performed by maintaining a normal flow rate when processing the sample until a predetermined pressure falls within a second predetermined range. 4. The control in which the exhaust amount exhausted from the processing chamber is increased stepwise to set a predetermined exhaust amount,
Until the pressure in the processing chamber falls within a first predetermined range with respect to the predetermined pressure, the exhaust amount is set to a first exhaust amount that is smaller than a normal exhaust amount when processing the sample, Next, after the pressure in the processing chamber is within the first predetermined range, the normal exhaust volume for processing the sample is maintained until the pressure within the first predetermined range is within the second predetermined range. The dry process method according to claim 2, wherein the dry process method is performed by 5. The flow rate and the exhaust gas amount when the processing chamber is maintained at the predetermined pressure for a predetermined time is newly set as the predetermined flow rate or the predetermined pressure. The dry process method according to claim 2.