JPH02148836A - Vacuum processor - Google Patents

Abstract

PURPOSE:To prevent fatigue and deterioration of the diaphragm, etc. of a pressure sensor by releasing the opening/closing valve of the detection tube of a main switch when gas pressure in a processing chamber becomes a higher predetermined intermediate set value than the finally set value. CONSTITUTION:When a vacuum pump 51 is operated, discharge gas in a processing chamber flows into a discharge gas tube 49, is discharged from the pump 51 to the exterior, and the pressure in the chamber is reduced. In this case, while the gas pressure in the chamber is higher than 50Torr, opening/ closing valve 55 is closed by a pump auxiliary switch 58. When the gas pressure in the chamber becomes a set value such as 50Torr, the valve 55 is opened by the switch 58, and when the pressure in the chamber becomes 1.0X10<-2>Torr, the pump 51 is stopped by a pump main switch 57. Accordingly, fatigue and deterioration of the diaphragm, etc. of a pressure sensor contained in the switch 57 are prevented, and the detected value of the switch 57 is not deviated from 1.0X10<-2>Torr.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a vacuum processing apparatus.

(Prior Art) Vacuum processing apparatuses, for example, etching apparatuses in which a semiconductor substrate is held by one of opposing electrodes provided in a processing chamber under an extremely low pressure state and which etches the semiconductor substrate, are known.

Conventionally, the process chamber of such an etching apparatus was brought into an extremely low pressure state in the following manner.

That is, a vacuum pump reduces the pressure in the processing chamber, and a pump switch adjusts the pressure in the processing chamber to a set value (for example, Q, Q
ITorr), and when this set value is reached, the vacuum pump is stopped.

(Problem to be Solved by the Invention) However, the above-mentioned pump switch uses a pressure sensor such as a diaphragm sensor, and such a pressure sensor is
When repeatedly exposed to extremely low pressure conditions such as rr, the diaphragm of the pressure sensor progresses in fatigue and deterioration, causing a problem in that the detected pressure deviates from the set value.

The present invention was made to solve such problems,
The purpose is to provide a vacuum processing apparatus in which the detected pressure of the vacuum pump switch does not deviate from the set value.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a vacuum pump capable of reducing the atmospheric pressure in a processing chamber to a final setting value that is an extremely low pressure state necessary for processing; a main switch that stops the vacuum pump when the atmospheric pressure in the processing chamber reaches a final set value; and a main switch that stops the vacuum pump when the atmospheric pressure in the processing chamber reaches a predetermined intermediate set value higher than the final set value. The present invention is characterized by the provision of an auxiliary switch for opening and closing the detection tube.

(Function) In the present invention, the pressure inside the processing chamber is reduced by the vacuum pump, but while the atmospheric pressure inside the processing chamber is higher than the intermediate setting value, the opening/closing pulp of the detection tube of the main switch is closed by the auxiliary switch. When the pressure inside the processing chamber reaches the intermediate setting value,
The opening/closing pulp is opened by means of an auxiliary switch. When the atmospheric pressure in the processing chamber reaches the final set value, the vacuum pump is stopped by the main switch.

(Embodiment) An etching apparatus according to an embodiment of the present invention will be described below based on the drawings.

As shown in FIG. 2, this etching device has a main body 6.
It can be operated manually using the operation keys 66 provided at the bottom of the display screen 64, with reference to processing data displayed on the display screen 64 in the center of the display screen 64 from time to time.

A foldable carrier mounting table 68 is provided on both sides of the main body 62.
A carrier 70 for storing a plurality of (for example, 25) semiconductor substrates can be placed thereon, and the work space can be used effectively. Note that the carrier mounting table 68 is configured as follows. A mounting plate 68a is mounted on the side surface of the main body 62, and one end of the mounting plate 68a rotates around the horizontal direction (the second
(A direction in the figure) can be attached freely. The lower surface of the mounting plate 68a has a main body 62 when the mounting plate 68a is horizontal.
A support plate 68b is attached so as to be rotatable (in the direction of B in FIG. 2) about the vertical direction of the side surface of the support plate 68b. When the support plate 68b is made vertical, the mounting plate 68a is supported horizontally, but in this case, the support plate 68b is moved by the stopper 68 provided on the side surface of the main body.
fixed by c.

The main parts of this etching apparatus are constructed as follows.

A grounded disc-shaped lower electrode 3 is provided on the support member 1 provided on the device main body 62. A disc-shaped upper electrode 5 connected to a high frequency power source 4 is provided above the lower electrode 3 and facing the lower electrode 3 . The upper electrode 5 has a hollow structure, has a large number of gas passage holes 7 on a surface facing the lower electrode 3, and is connected to a gas supply pipe 9 via an insulating member 8.

The gas supply pipe 9 is selectively connected to a reaction gas supply device 11 and a nitrogen gas supply device 13. Reaction gas supply device 1
The reaction gas supply from 1 is controlled by a reaction gas pulp 15. The nitrogen gas supply from the nitrogen gas supply device 13 is controlled by a nitrogen gas pulp 17.

An aluminum processing chamber wall 19 is provided around the lower electrode 3 to form a lower housing.

An electromagnetic shielding cover 21 made of aluminum and having an upper electrode 5 therein is provided above the lower housing.
An upper housing is formed.

A backing 23 is provided on the upper end surface of the processing chamber wall 19,
The lower surface of the electromagnetic shielding cover 21 is configured to be able to come into contact with it in an airtight manner.

A cylindrical sliding member 27 is provided around the gas supply pipe 9 above the upper electrode 5 . The side surface of the sliding member 27 is slidable in the vertical direction relative to the electromagnetic shielding cover 21, but by interposing the backing 29,
Airtightness is maintained.

A rectangular flat support plate 31 is provided on the upper end surface of the sliding member 27 and around the gas supply pipe 9 . Connection arms 33 are fixed to the four corners of the support plate 31 , a motor 35 is fixed to one of the four connection arms 33 , and a support shaft 37 is fixed to the other connection arms 33 .

A rotating rod 39 is vertically connected to a rotating shaft (not shown) of the motor 35, and is also vertically connected to a bearing (not shown) of the support shaft 37. Each rotating rod 39 passes through the support plate 31 and further extends through the support plate 31.
A bearing 32 is interposed between the two. A ball screw 41 is formed at the bottom of each rotating rod 39 . The ball screw 41 is fixedly installed through the lower part of the electromagnetic shielding cover 21. On the other hand, a thrust bearing 4 is mounted around the rotating rod 39 in contact with the lower surface of the support plate 31.
3 is provided. A sprocket 45 is provided around the rotating rod 29 in contact with the lower surface of the thrust bearing 43. Each sprocket 45 is connected by a chain 47. Therefore, in conjunction with the rotation of the motor 35, the 4
The two ball screws 41 operate in synchronization.

An exhaust gas pipe 49 is provided at the lower part of the processing chamber wall 19 and is connected to a vacuum pump 51 .

On the side surface of the processing chamber wall 19, pressure detection tubes 53 and 54 are provided to introduce the pressure inside the processing chamber. The pressure detection tube 53 is
It is connected to a pump main switch 57 via an opening/closing pulp 55. The pressure detection tube 54 is connected to a pump auxiliary switch 58 via an opening/closing valve 56 . Pump main switch 5
7 and the pump auxiliary switch 58 have built-in diaphragm pressure sensors (not shown). The pump main switch 57 is connected to the vacuum pump 51 and opens/closes the pulp 55.
When the vacuum pump 51 is released, the pressure inside the processing chamber is detected, and when it reaches the final set value (in this case, 1.OX 1O-2 Torr), the operation of the vacuum pump 51 is stopped. The pump auxiliary switch 58 is set so that the atmospheric pressure inside the processing chamber is at an intermediate setting value (in this case, 50T).
orr), the opening/closing pulp 55 is opened.

Next, the operation of this etching apparatus will be explained.

First, the motor 35 is operated by a motor control device (not shown), the upper electrode 5 is moved in the vertical direction, and the distance between the upper electrode 5 and the lower electrode 3 is adjusted to a state suitable for etching.

Then, by operating the vacuum pump 51, the exhaust gas inside the laboratory flows into the exhaust gas pipe 49, and the vacuum pump 51 flows into the exhaust gas pipe 49.
1 to the outside, and the pressure inside the processing chamber is reduced. At this time, the open/close pulp 55 is closed by the pump auxiliary switch 58 while the atmospheric pressure in the processing chamber is higher than 50 Torr. The atmospheric pressure inside the processing chamber is set to 50 Torr, for example.
When this happens, the opening/closing pulp 55 is opened by the pump auxiliary switch 58. Eventually the pressure inside the processing chamber drops to 1. ox
When the pressure reaches 10'-2 Torr, the vacuum pump 51 is stopped by the pump main switch 57. Also, during the etching process described below, the vacuum pump 51 similarly exhausts the exhaust gas in the process chamber, and the pump main switch 57 and pump auxiliary switch 58 detect and control the atmospheric pressure value to maintain a constant atmospheric pressure. drooping

Next, the semiconductor substrate 61 is carried by a transport means (not shown) from a vacuum preliminary chamber (not shown), which has been previously depressurized in the same manner as the processing chamber, and placed on the lower electrode 3 in the processing chamber.

Here, the reaction gas is supplied into the reaction chamber from the reaction gas supply device 11 via the gas supply pipe 9 and the gas passage hole 7 .

Then, a high frequency voltage is applied from the high frequency power supply 4 to the upper electrode 5, plasma is generated from the reaction gas, and the semiconductor substrate 61 is plasma etched.

Thereafter, the etched semiconductor substrate 61 is transported by a transport means (not shown) to a vacuum preliminary chamber (not shown) which has been previously depressurized in the same manner as the inside of the processing chamber.

Such operations are repeated for each individual semiconductor substrate.

Note that when cleaning the inside of the processing chamber with nitrogen gas during maintenance of this etching apparatus, the vacuum pump 51 is
The exhaust gas in the reaction chamber is discharged via the exhaust gas pipe 49, and the gas supply pipe 9,
Nitrogen gas is supplied into the reaction chamber through the gas passage hole 7.

Thus, according to this embodiment, the atmospheric pressure inside the processing chamber is 50To
While the temperature is higher than rr, the opening/closing pulp 55 is closed by the pump auxiliary switch 58, and the pump main switch 5
The pressure sensor within 7 is never exposed to pressure conditions higher than 50 Torr. Therefore, fatigue and deterioration of the diaphragm of the pressure sensor built into the pump main switch 57 are prevented, so that the detected value of the pump main switch 57 is 1. Ox does not deviate from 1O-2Torr.

Also, by periodically comparing and correcting errors in the auxiliary switch using the main switch, highly reliable values can be obtained.

In this example, the pressure sensors built into the auxiliary switch and the main switch were of diaphragm type.
It goes without saying that the present invention is not limited to this, and for example, an auxiliary switch and a main switch incorporating various pressure sensors such as a bellows type can be used.

In the above embodiment, an example was explained in which it was applied to an etching device, but if it is a vacuum processing device, sputtering, CVD
, an ion implantation device, etc.

[Effects of the Invention] As explained in detail above, according to the present invention, while the atmospheric pressure in the processing chamber is higher than the intermediate setting value, the opening/closing pulp of the detection tube of the main switch is closed by the auxiliary switch,
The pressure sensor in the main switch is never exposed to pressure conditions higher than the intermediate set point. Therefore, fatigue and deterioration of the diaphragm and the like of the pressure sensor are prevented, so it is possible to provide a vacuum processing apparatus in which the detected value of the pump switch does not deviate from the final set value.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the main parts of the etching apparatus of this embodiment, and FIG. 2 is a diagram showing the external appearance of the etching apparatus shown in FIG. 1. 51...Vacuum pump 53.54...Pressure detection tube 55.56.
......Opening/closing pulp 57...Pump main switch 58...Pump auxiliary switch hand

Claims (1)

[Scope of Claims] In a processing apparatus that processes a semiconductor substrate by holding a semiconductor substrate on one of opposing electrodes provided in a processing chamber in an extremely low pressure state, the atmospheric pressure in the processing chamber is set to an extremely low pressure state necessary for etching. a vacuum pump that can reduce the pressure to a final set value, a main switch that stops the vacuum pump when the pressure in the processing chamber reaches the final set value, and a vacuum pump that can reduce the pressure to a final set value, and An etching apparatus comprising: an auxiliary switch that opens and closes the detection tube of the main switch when a predetermined intermediate setting value is reached.