JP2598105Y2 - Vacuum processing equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION This invention relates to an apparatus for processing an object to be processed in a vacuum, such as an ion implantation apparatus, an ion beam etching apparatus, a thin film forming apparatus, etc., in which the object to be processed is housed. The present invention relates to a so-called vented vacuum processing apparatus for introducing a gas into a vacuum vessel to return the inside of the vacuum vessel to an atmospheric pressure state.

[0002]

2. Description of the Related Art FIG. 2 is a schematic front sectional view showing an example of a conventional vacuum processing apparatus. Reference numeral 1 denotes a vacuum container which is evacuated by a vacuum pump 3 via a vacuum valve 2 and contains a carrier 5 on which an object 4 such as a wafer is placed, for example. 6 is the vacuum vessel 1
Is connected to a gas cylinder (not shown) filled with a vent gas 8 such as nitrogen gas through a valve 7 and a filter (not shown). Reference numeral 10 denotes a mounting table on which the carrier 5 is mounted, and 11 denotes a shaft for elevating the mounting table.
The shaft 11 is moved up and down by a lifting mechanism (not shown). Reference numeral 9 denotes a shutter for opening and closing the loading / unloading port of the object 4 to be processed.

[0003] In the illustrated example, the vacuum vessel 1 is provided with air for moving the object 4 between the atmospheric pressure side A and a processing chamber (not shown) for processing the object 4, for example, ion implantation. It constitutes a lock room.

[0004] An example of the operation of the vacuum processing apparatus will be described. The shutter 9 is opened, and the vacuum vessel 1 under atmospheric pressure is opened.
After storing the carrier 5 on which the unprocessed object 4 is placed, the shutter 9 is closed and the vacuum valve 2 is closed.
Is opened, and the inside of the vacuum vessel 1 is evacuated by the vacuum pump 3.
After the inside of the vacuum chamber 1 reaches a desired degree of vacuum, a door (not shown) provided between the vacuum chamber 1 and an adjacent processing chamber is opened, and the object 4 is transferred into the processing chamber. The door is closed and desired ions are implanted into the processing target 4 in the processing chamber. Thereafter, the door is opened, the processed object 4 is transferred from the processing chamber into the carrier 5 in the vacuum vessel 1, and the door is closed. afterwards,
The valve 7 is opened, the gas 8 is introduced into the vacuum vessel 1 from the gas inlet 6, and the inside of the vacuum vessel 1 is returned to the atmospheric pressure state. The body 4 is carried out to the atmospheric pressure side. As a result, the above state is restored.

[0005]

In such a vacuum processing apparatus, the gas 8 is introduced from the gas inlet 6 into the vacuum vessel 1 as described above. There is a problem in that the processing target 4 is charged by friction between the processing target 4 and the gas 8 and adsorbs particles (fine particles) accumulated inside the vacuum vessel 1.
Further, the wall surface inside the vacuum vessel 1 is also charged, and particles adhere thereto, and these particles are adsorbed by the object to be processed 4 to cause contamination (contamination). In addition, such a problem tends to be further increased when the pressure and the flow rate of the gas 8 are increased in order to speed up the atmospheric pressure in the vacuum vessel 1.

Therefore, the present invention suppresses the charging of the object and the wall surface caused by introducing a gas into the vacuum vessel,
An object of the present invention is to provide a vacuum processing apparatus capable of suppressing adsorption and adhesion of particles.

[0007]

In order to achieve the above object, a vacuum processing apparatus according to the present invention is provided in the vacuum vessel.
An ion generator for generating positive ions and negative ions have been, the vacuum containers provided in the vacuum chamber
Sensor that detects the balance of positive and negative ions in the chamber
Section and a vacuum vessel receiving a signal from the sensor section.
So that the balance between positive and negative ions in the
A control unit for controlling the ion generator .

[0008]

According to the above arrangement, the positive charges and the negative ions supplied from the ion generator neutralize the electrostatic charges existing on the wall surface in the vacuum vessel and on the object to be processed, and the charge is removed. As a result, adhesion and adsorption of particles to the wall surface in the vacuum vessel and the object to be processed can be suppressed.

[0009]

FIG. 1 is a front sectional view showing a schematic configuration of a vacuum processing apparatus according to an embodiment of the present invention. Parts that are the same as or correspond to those in the conventional example of FIG. 2 are denoted by the same reference numerals, and differences from the conventional example will be mainly described below.

In this embodiment, an ion generator 20 for generating positive ions and negative ions is provided on the ceiling of the vacuum vessel 1 as described above. In this embodiment, the ion generator 20 includes a needle end electrode 21 to which a DC positive high voltage is applied from a power supply (not shown) and a needle end electrode 21 to which a DC negative high voltage is applied from the same power supply. The positive electrode and the negative ion are generated in good balance by corona discharge between the needle end electrode 21 and the ground conductor, and the positive ions and the negative ions are supplied into the vacuum vessel 1. Further, in the ion generator 20, the sensor unit 22 detects the balance of positive and negative ions in the vacuum vessel 1 and sends a signal to a control unit (not shown) so that the balance between positive and negative ions is always kept correct. It has a self-control function as described below.

With the above construction, when the valve 7 is opened to introduce the gas 8 from the gas inlet 6 into the vacuum vessel 1 and return to the atmospheric pressure state, as described above, the gas in the vacuum vessel 1 is removed. Even if the processing body 4 and the wall surface of the vacuum vessel 1 are charged, the positive charges and the negative ions supplied from the ion generator 20 cause the electrostatic charges existing on the wall surface in the vacuum vessel 1 and the processing object 4 to be medium. And the charge is removed. As a result, it is possible to suppress adhesion and adsorption of particles to the wall surface in the vacuum vessel 1 and the object 4 to be processed.

Further, the inside of the vacuum vessel 1 can be always kept in a clean state with few particles, and the cleaning operation can be reduced.

As a result, contamination of the object to be processed 4 can be reduced. Further, by increasing the pressure and flow rate of the gas 8 introduced into the vacuum vessel 1, the speed of the atmospheric pressure in the vacuum vessel 1 can be increased, that is, the throughput can be improved.

The gas 8 only needs to be a clean gas, and of course may be other than nitrogen gas.

Further, depending on the apparatus, the object to be processed may be directly taken in and out between the processing chamber for processing the object to be processed and the atmospheric pressure side without providing the air lock chamber. Although the gas is introduced into the chamber and venting is performed, it goes without saying that the present invention can be applied to such a case. In this case, the vacuum vessel 1 may be formed as a processing chamber.

[0016]

As described above, according to the present invention, since the ion generator is provided in the vacuum vessel, the positive ions and the negative ions supplied from the ion generator cause the wall surface in the vacuum vessel and the processing target to be processed. The static charge present on the body is neutralized,
Static elimination is performed. That is, gas is introduced into the vacuum vessel.
To suppress the charging of the workpiece and the inner wall of the vacuum vessel
Can be As a result, adhesion and adsorption of particles to the wall surface in the vacuum vessel and the object to be processed can be suppressed. Moreover, it has a sensor unit and a control unit as described above.
The balance of positive and negative ions in the vacuum vessel
Balance) can always be maintained.

Further, the inside of the vacuum container can be always kept in a clean state with few particles, so that the cleaning operation can be reduced and the charge-up of the object to be processed can be reduced.

As a result, contamination to the object to be processed can be reduced, and dielectric breakdown of the surface of the object to be processed due to charge-up can be prevented. In addition, the pressure and flow rate of the gas introduced into the vacuum vessel are increased to increase the speed of the atmospheric pressure in the vacuum vessel, thereby improving the throughput.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a schematic configuration of a vacuum processing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic front sectional view showing an example of a conventional vacuum processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 4 Object to be processed 6 Gas inlet 8 Gas 20 Ion generator 21 Needle end electrode

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C23C 14/00-14/58 C23C 16/50 C23F 4/00 H01J 37/317

Claims (1)

(57) [Scope of request for utility model registration] 1. A vacuum vessel evacuated to a vacuum, in which an object to be processed is housed therein, by introducing a gas from a gas inlet to return the inside of the vacuum vessel to an atmospheric pressure state. Vacuum processing apparatus, provided in the vacuum vessel
An ion generator for generating positive ions and negative ions have been, the vacuum containers provided in the vacuum chamber
Sensor that detects the balance of positive and negative ions in the chamber
Section and a vacuum vessel receiving a signal from the sensor section.
So that the balance between positive and negative ions in the
A vacuum processing apparatus comprising: a control unit that controls an ion generator .