JPH05295569A - Plasma working device - Google Patents

Abstract

PURPOSE:To provide a plasma working device capable of efficiently and highly precisely working a body using a clustered electrode. CONSTITUTION:A clustered electrode 4 having the surface shape corresponding to the shape to be worked is disposed opposing to a body 3 to be worked in a reduced-pressure gas with the minute gap in between, discharge plasma is produced between the body 3 and the electrode 4, a plasma gas is supplied to the surface region of the electrode 4 while controlling the amt., and the body 3 is worked. The supply of the plasma gas is adjusted in accordance with the size of the gap between the body and electrode, the body is used as one electrode, or a bias voltage obtained by superimposing a high-frequency current on a DC current is impressed to work the body. Consequently, since the supply of the plasma gas is controlled so that the plasma is uniformly concentrated on the surface region of the electrode, the body is efficiently and highly precisely worked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus.

[0002]

2. Description of the Related Art Reactive radical species such as fluorine and chlorine atoms produced in plasma are blown onto a workpiece to process volatile molecules generated by the reaction between the atoms of the workpiece and the reactive radical species. A plasma processing apparatus that etches a workpiece by carrying it away from near the surface of the body is known. However, when processing is performed using a forming electrode having a surface shape corresponding to the shape to be processed, the plasma is concentrated in a specific region to be processed, and the predetermined shape corresponding to the forming electrode is efficiently and efficiently increased. It was difficult to process with precision.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to perform processing efficiently and with high precision using a forming electrode. It is to provide a plasma processing apparatus capable of performing the above.

[0004]

The above-mentioned object is to make a forming electrode having a surface shape corresponding to a shape to be processed face a work piece in a depressurized gas with a minute gap therebetween so that the work piece and the work piece are made together. This can be achieved by a plasma processing apparatus characterized in that discharge plasma is generated between the mold electrodes and plasma gas is supplied to the surface region of the all-mold electrode while controlling the increase and decrease to process the workpiece.

In that case, it is also recommended to control the supply amount of the plasma gas to be increased or decreased according to the amount of the minute gap between the workpiece and the forming electrode, and it is recommended to use a halogen mixed gas as the plasma gas. To be done. It is also recommended that the work piece is processed as one pole, or that a bias voltage in which a high frequency wave is superimposed on a direct current is applied to perform the work. Furthermore, N should be set so that plasma is not generated on the entire surface of the pattern electrode.
It is also recommended to control the C drive and the plasma gas pressure to move the partial plasma over the entire surface of the forming electrode to perform processing.

[0006]

With the above-described structure, the plasma gas supply amount can be controlled to be increased or decreased so that the plasma is concentrated and uniformly generated on the surface area of the forming electrode, so that efficient and highly accurate processing can be performed. Is possible.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. FIG. 1 is an explanatory view showing an embodiment of the plasma processing apparatus according to the present invention, in which 1 is a processing chamber, 2 is a vacuum pump for reducing the pressure inside the processing chamber, 3 is a workpiece, 4 is a workpiece. Forming electrodes, 4a, 4b and 4c are plasma gas supply holes formed in forming electrode 4, 5 is a processing head chucking forming electrode 4, 6 is a processing feed device for moving processing head 5 in the vertical direction, 7 Is a plasma gas supply device, 8a, 8b and 8c are flow rate adjusting valves, 9 is a plasma generating power source, 10 is the plasma generating power source 9 and the machining feed device 6 and flow rate adjusting valves 8a, 8b, 8c
It is a control device that controls the operation of the entire device by controlling the operations of the above.

During processing, a vacuum pump 2 is used in the processing chamber 1.
The pressure is reduced to about 10 ^-5 to 10 ^-9 Torr, the forming electrode 4 is made to face the work piece 3 with a slight gap, and the work piece and the forming electrode are formed by the voltage applied from the plasma generating power source 9. During this period, plasma is generated to perform plasma processing on the workpiece. At this time, the forming electrode 4 attached to the processing head 5 is slowly fed toward the workpiece 3 by the processing feeding device 6 in accordance with the progress of processing so as to maintain a constant gap with the workpiece 3. ..

In the region where the discharge electrode 4 and the workpiece 3 are opposed to each other and discharge plasma is formed by the voltage from the power source 9, the plasma gas supply holes 4a formed in the discharge electrode 4 are formed.
A halogen-containing gas is supplied from the plasma gas supply device 7 through 4b and 4c. This gas is
When the pressure in the processing chamber 1 is reduced to about 10 ^-5 to 10 ^-9 Torr as described above, the plasma formation region has a function of concentrating the plasma by increasing the pressure in the plasma formation region above the ambient pressure. The pressure in the area should be kept at about 1-50 Torr.

However, in this case, the plasma generation state varies variously depending on the surface shape of the forming electrode 4, the amount of the gap between the workpiece 3 and the like, so that the respective flow rates of the flow rate adjusting valves 8a, 8b, 8c are changed. By controlling and adjusting the supply amount of the plasma gas supplied to the plasma generation region or the ejection pressure, uniform plasma is generated in a concentrated manner in a specific region to be processed.

In the apparatus configured as described above, when the workpiece is Si single crystal, SF gas is used as the plasma gas.
A mixed gas of ₆ + O ₂ + N ₂ (mixing ratio 2: 1: 1) is used, and this gas is jetted and supplied through the plasma gas supply holes 4a, 4b and 4c so that the pressure in the processing gap becomes 15 Pa to 30 Pa. As a result of performing gas exchange in the machining gap and generating plasma of 13.56 MH with an output of 4000 W in the surface area of the machined shape of the forming electrode, the machining speed was improved by about 50% and the high We were able to perform precision processing.

Further, by adding a bias voltage of about 400 V to the plasma generation voltage, the processing speed is further increased to 10 to
It was found to improve by about 30%. Further, when a bias voltage in which a high frequency is superimposed on DC is applied, the electron action is reduced at 100 V / cm, and the heating action can be suppressed to about 80%.

The present invention is not limited to the above-described embodiment. For example, in addition to jetting the plasma gas from the hole formed in the forming electrode, a nozzle or the like is provided to jet the plasma gas toward the machining gap. Therefore, within the scope of the object of the present invention, the present invention covers all modifications which can be easily conceived by a person skilled in the art from the above description.

[0014]

Since the present invention is constructed as described above, according to the present invention, the supply amount of the plasma gas is increased or decreased so that the plasma is concentrated and uniformly generated in the surface area of the processed shape of the forming electrode. Since it can be controlled, a predetermined shape corresponding to the formed electrode can be processed efficiently and highly accurately.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a plasma processing apparatus according to the present invention.

[Explanation of symbols]

 1 Processing chamber 2 Vacuum pump 3 Workpiece 4 Forming electrode 4a, 4b, 4c Plasma gas supply hole 5 Processing head 6 Processing feed device 7 Plasma gas supply device 8a, 8b, 8c Flow rate control valve 9 Plasma generation power supply 10 Control apparatus

Claims (6)

[Claims] 1. A mold electrode (4) having a surface shape corresponding to the shape to be processed is made to face the object to be processed (3) in a depressurized gas with a minute gap, and the object to be processed (3) and the electrode. A discharge plasma is generated between the mold electrodes (4) and the plasma gas is supplied to the surface area of the total mold electrode (4) while controlling the increase and decrease of the workpiece.
A plasma processing apparatus characterized by being configured to perform the processing of (3). 2. The plasma processing apparatus according to claim 1, wherein the supply amount of the plasma gas is controlled to increase or decrease according to the amount of the minute gap. 3. The plasma processing apparatus according to claim 1, wherein a halogen mixed gas is injected as the plasma gas. 4. The plasma processing apparatus according to claim 1, wherein the object to be processed (3) is processed as one pole. 5. The plasma processing apparatus according to claim 1, wherein a bias voltage in which a high frequency is superimposed on a direct current is used as the plasma generation voltage. 6. Processing is performed while moving partial plasma to the entire surface of the forming electrode (4) by controlling NC driving and plasma gas pressure so as not to generate plasma on the entire surface of the forming electrode (4). The plasma processing apparatus according to any one of claims 1 to 5, configured as described above.