JPH08236510A - Microwave plasma processing device and processing method - Google Patents

Abstract

PURPOSE: To realize uniform plasma treatments by applying a magnetic field in the vertical direction by using an electric field caused by microwaves and an air-core coil to generate a high density plasma, and controlling the direction of magnetic line of force caused by a magnetic field generation means installed near a sample so as to become almost parallel on the sample. CONSTITUTION: In the case where the dimension of an inside diameter of an air-core coil 6 which is a magnetic field generation means, is large enough compared with the diameter of a sample 1, the sample 1 is laid out at a spot parallel to a magnetic line of force generated with the air-core coil 6. The ions contained in the plasma of a processing gas in a vacuum chamber 3 which is generated by a synergism between the electric field produced by microwaves and the magnetic field produced by the coil 6, is introduced in a spiral motion to the sample 1 in such a fashion that the ions may be coiled around the magnetic field substantially vertical and parallel to the sample 1 or more specifically, around the magnetic field whose flux density is substantially uniform so that they may be reacted with the sample 1 and processed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave plasma processing apparatus and processing method for processing a sample with plasma generated using microwaves.

[0002]

2. Description of the Related Art A conventional apparatus is disclosed in Japanese Examined Patent Publication Sho 53-34461.
The sample is arranged at the end of the magnetic field by the magnetic field generating means as described in No. 6, and the incident angle of the magnetic force line indicated by the broken line differs between the central part and the peripheral part of the sample as shown in FIG.

[0003]

In the above prior art, the sample to be processed is arranged in a divergent magnetic field, and the incident angle of the magnetic force lines incident on the sample surface and the density of the magnetic force line density are not taken into consideration. , Had the following problems.

Ions in the plasma spiral so as to be wrapped around the magnetic field lines, and when the potential acting on the sample is small with respect to the magnetic field, they enter the sample at an angle forced by the magnetic field lines. This means that if the magnetic field forms a diverging magnetic field,
The incident angle of ions is different between the central part and the peripheral part of the wafer, which causes a difference in processing characteristics.

An object of the present invention is to provide a microwave plasma processing apparatus and a processing method capable of homogenizing processing characteristics in plasma processing in which ions are the main constituent and a reaction occurs.

[0006]

The features of the present invention are: a vacuum container, a sample stage provided in the vacuum container and having a sample mounting surface for holding a sample, and an evacuation means for evacuating the inside of the vacuum container under reduced pressure. A microwave provided with a processing gas supply means for supplying a processing gas into the vacuum container, a microwave generation means, and a microwave introduction means for introducing the microwave generated by the microwave generation means into the vacuum container. In a microwave plasma processing apparatus, an air-core coil arranged outside the vacuum container along a direction of introduction of the microwave and a magnetic field generating means arranged in the vicinity of the sample mounting surface, and the direction of magnetic field lines is A vertical magnetic field forming means for forming a vertical magnetic field perpendicular to the sample mounting surface from the microwave introducing means to the sample mounting surface over the entire surface of the sample mounting surface; Field and the vertical magnetic field synergize the processing gas in the vacuum container to generate ions, and the ions are moved in the direction along the vertical magnetic field so as to move over the entire surface of the sample mounting surface. And a plasma generating means for making the incident.

Another feature of the present invention is that the microwave generated by the microwave generating means is introduced into the vacuum container through the microwave introducing means, and the electric field generated by the microwave and the magnetic field formed by the magnetic field forming means are synergistic. In the method of converting the processing gas in the vacuum container into plasma by the action, and processing the sample on the sample mounting surface provided on the sample table in the vacuum container by the plasma, the magnetic field forming means includes An air-core coil arranged outside the vacuum container along the introduction direction and a magnetic field generating means arranged in the vicinity of the sample mounting surface, the direction of the magnetic force lines being micro by the air-core coil and the magnetic field generating means. A vertical magnetic field perpendicular to the sample mounting surface from the wave introducing means to the sample mounting surface,
It is formed over the entire surface of the sample mounting surface, and the processing gas in the vacuum container is plasmatized by the synergistic action of the electric field by the microwave and the vertical magnetic field to generate ions, which are generated along the vertical magnetic field. In this case, the surface to be processed of the sample is treated with the ions by causing the ions to move over the entire surface of the sample mounting surface while being aligned in the same direction.

According to the present invention, the magnetic field in the vertical direction is applied to the electric field generated by the microwave by the air-core coil to generate the high density gas plasma, and the magnetic field generating means installed near the sample changes the direction of the magnetic force lines. The sample is controlled so as to be substantially parallel to it. Thereby, a vertical magnetic field in which the direction of the line of magnetic force is perpendicular to the sample mounting surface from the microwave introducing means to the sample mounting surface can be formed over the entire surface of the sample mounting surface. By making the lines of magnetic force substantially vertical and parallel to the sample, the ions dissociated in the plasma enter the sample along the lines of magnetic force. By arranging the sample in the substantially uniform portion of the magnetic field, the magnetic force lines are substantially perpendicular to the sample, and the ions are incident on the sample along the substantially perpendicular magnetic force lines, which enables uniform processing.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. The sample 1 is mounted on the sample mounting surface on the sample table 2, and the sample table 2 is installed in the vacuum chamber (vacuum container) 3. A bell jar 4 formed of an insulating material that transmits microwaves is attached to the upper portion of the vacuum chamber 3. A circular waveguide 5 is provided on the outer periphery of the bell jar 4, and an air-core coil 6 which is a magnetic field generating means for generating a magnetic field is arranged outside the circular waveguide 5. Reference numeral 7 denotes a microwave introduction port as a microwave introduction means for introducing a microwave from a microwave generation source (not shown). A gas supply port 8 is connected to a processing gas supply source (not shown) and supplies the processing gas into the vacuum chamber 3.
Reference numeral 9 denotes a vacuum exhaust port connected to an exhaust device (not shown) for reducing the pressure inside the vacuum chamber 3 to a predetermined pressure.

When the inner diameter of the air-core coil 6 which is the magnetic field generating means is sufficiently larger than the diameter of the sample by the apparatus having the above-mentioned structure, the lines of magnetic force generated by the air-core coil 6 are parallel to each other. By placing the sample in place,
Ions in the plasma of the processing gas in the vacuum chamber 3 generated by the synergistic action of the electric field generated by the microwave and the magnetic field generated by the air-core coil 6 have a magnetic field substantially perpendicular and parallel to the sample, that is, a magnetic flux density of It is spirally wound around a substantially uniform magnetic field, is guided to the sample, and reacts with the sample to be processed.

As described above, according to the present embodiment, the air-core coil 6
By arranging the sample 1 in a place where the directions of magnetic force lines are aligned in the magnetic field generated by, the ions in the gas plasma generated by the synergistic action of the electric field by the microwave and the magnetic field by the air-core coil 6 Since it is guided vertically, there is an effect that uniform processing can be performed with ions.

In this embodiment, the case where the inner diameter of the air-core coil 6 is large has been described, but the inner diameter of the air-core coil 6 is close to the diameter of the sample 1 or the air-core coil 6 of the above-mentioned embodiment. If it is smaller, another magnetic field generating means is arranged near the sample and the direction of the magnetic force lines is controlled to be substantially parallel on the sample 1, or the direction of the magnetic force lines is changed by utilizing the diaphragm effect of the non-magnetic material. Similar effects can be obtained by making them substantially parallel to each other on the sample.

[0013]

According to the present invention, a sample is plasma-treated by a synergistic effect of an electric field generated by a microwave and a magnetic field generated by a magnetic field generating means, and the sample is arranged in a substantially uniform magnetic field. As a result, the magnetic field is guided to a substantially vertical magnetic field in a portion where the magnetic flux density is substantially uniform, and the ions in the plasma enter the sample and react with the sample, so that the processing characteristics can be homogenized.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a microwave plasma processing apparatus showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a conventional microwave plasma processing apparatus.

[Explanation of symbols]

1 ... sample, 2 ... sample stage, 3 ... vacuum chamber, 4 ... bell jar,
5 ... Circular waveguide, 6 ... Air core coil, 7 ... Microwave inlet, 8 ... Gas supply port, 9 ... Vacuum exhaust port

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // C23F 4/00 C23F 4/00 C G D

Claims (2)

[Claims] 1. A vacuum container, a sample stage provided in the vacuum container and having a sample mounting surface for holding a sample, exhaust means for decompressing and exhausting the inside of the vacuum container, and supplying a processing gas into the vacuum container. Processing gas supply means, microwave generation means,
A microwave plasma processing apparatus comprising: a microwave introducing unit that introduces a microwave generated by the microwave generating unit into the vacuum container, wherein the microwave plasma processing device is arranged outside the vacuum container along a direction in which the microwave is introduced. An air-core coil and magnetic field generating means arranged in the vicinity of the sample mounting surface, and the direction of the lines of magnetic force is perpendicular to the sample mounting surface from the microwave introducing means to the sample mounting surface. A vertical magnetic field, a vertical magnetic field forming means for forming the entire surface of the sample mounting surface, and a synergistic action of the electric field by the microwave and the vertical magnetic field to plasmaize the processing gas in the vacuum container to generate ions, Plasma generating means for causing the ions to move in a direction along the vertical magnetic field so as to be incident on the entire surface of the sample mounting surface. Black wave plasma processing apparatus. 2. A microwave generated by the microwave generating means is introduced into the vacuum container through the microwave introducing means, and the electric field generated by the microwave and the magnetic field formed by the magnetic field forming means synergistically act in the vacuum container. In the method of converting the processing gas into a plasma, and processing the sample on the sample mounting surface provided on the sample table in the vacuum container by the plasma,
The magnetic field forming means includes an air-core coil arranged outside the vacuum container along the introduction direction of the microwave and a magnetic field generating means arranged near the sample mounting surface,
By the air-core coil and the magnetic field generating means, a vertical magnetic field whose direction of magnetic force lines is perpendicular to the sample mounting surface from the microwave introducing means to the sample mounting surface is applied to the entire surface of the sample mounting surface. Forming a plasma of the processing gas in the vacuum container by the synergistic action of the electric field generated by the microwave and the vertical magnetic field to generate ions, and the ions are moved in a direction along the vertical magnetic field. A microwave plasma processing method, characterized in that the surface to be processed of the sample is processed by being made incident on the entire surface of the sample mounting surface.