JPH088239B2 - ECR plasma device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a means for generating a microwave, a means for transmitting the microwave, and a microwave which is coupled to the means for transmitting the microwave. The gas introduced through the gas supply means is coaxially surrounded by a solenoid that generates magnetic lines of force that generate active atoms, molecules, or ions by plasmaizing the gas by the resonance effect with the microwaves, and is transported along the magnetic lines of force. Said activity being an atom,
The present invention relates to an ECR plasma device provided with a vacuum container in which a substrate whose surface is etched or molecules are formed by molecules or ions is arranged, and an exhaust means for exhausting the vacuum container.

[Conventional technology]

FIG. 3 shows a configuration example of a conventional ECR plasma device. Although not shown here, this device includes a waveguide 1 for transmitting microwaves oscillated from a magnetron as a means for generating microwaves, and a vacuum window 2 made of a dielectric material.
The microwave is introduced through the gas supply means 4
Exciting solenoid 6 for generating a magnetic force line 8 which turns the gas introduced through the plasma into a plasma by the resonance effect with the introduced microwave and produces active atoms, molecules or ions.
A vacuum container 3 in which is arranged a substrate 11 whose surface is etched or a thin film is formed by the active atoms, molecules or ions that are coaxially surrounded by and are transported along the magnetic field lines 8, and this vacuum container. And an exhaust means (not shown) for exhausting the exhaust gas.

When the substrate surface is etched by the ECR plasma apparatus configured as described above, the etching gas is sent from the gas supply means 4 to the plasma generation unit 7 in the vacuum container 3 to generate plasma, which is generated by this plasma generation. The active atoms, molecules or ions are transferred to the substrate surface along the magnetic lines of force 8 to etch the substrate surface. When a thin film is formed on the surface of the substrate, first, the gas supply means 4
From this, a plasma source gas such as N ₂ is sent to the plasma generation part 7 in the vacuum container 3 to turn it into plasma. This plasma is extruded from the opening 7a of the plasma generation unit to the processing unit 9 along the magnetic lines of force 8, and activates the film forming gas fed into the processing unit through the film forming gas supply means 12 to act on the substrate surface. Then, a thin film is formed on the surface of the substrate.

[Problems to be Solved by the Invention]

The problems with the ECR plasma device configured as described above are as follows. That is, the plasma generated by the plasma generating unit 7 is transferred to the processing unit 9 along the magnetic lines of force 8. Therefore, the plasma acting on the substrate tends to concentrate in the central portion around the excitation solenoid axis position on the substrate surface, the processing speed of the substrate during etching or thin film formation is high in the central portion of the substrate, and slow in the peripheral portion, The distribution of processing speed could not be made uniform.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks in the conventional ECR plasma apparatus, and to make the processing speed distribution on the substrate surface uniform so that the substrate surface is uniformly etched or a uniform thin film is generated. Is to provide.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, means for generating microwaves, means for transmitting the microwaves, and means for supplying the microwaves coupled to the means for transmitting the microwaves and gas supply means The gas that has been introduced through the plasma is converted into plasma by the effect of resonance with the microwave and is surrounded by a solenoid that generates lines of magnetic force that generate active atoms, molecules or ions, and is phased along the lines of magnetic force. In an ECR plasma device equipped with a vacuum container in which a substrate whose surface is etched or a thin film is formed by various atoms, molecules or ions is arranged, and an exhaust means for exhausting the vacuum container, in the vicinity of the substrate. Generate a magnetic field line orthogonal to the solenoid axis and rotate the magnetic field line in a plane orthogonal to the solenoid axis. A rotating magnetic field generating means composed of two sets of sonoids connected to a two-phase AC power supply with a voltage phase shift of 90 degrees or three sets of solenoids connected to a three-phase AC power supply with a voltage phase shift of 60 degrees. It should be provided outside the vacuum container.

[Action]

In this way, when a magnetic field line that is orthogonal to the axis of the excitation solenoid is generated near the substrate, and this magnetic field line is rotated in a plane that is orthogonal to the axis of the excitation solenoid, a two-phase AC power source with a 90 ° voltage phase shift is created. By providing the rotating magnetic field generating means composed of two sets of connected sonoids or three sets of solenoids connected to a three-phase AC power supply with a voltage phase difference of 60 degrees outside the vacuum container, the central portion of the substrate is reached. The high-density plasma to be rotated rotates around the axis of the exciting solenoid while moving to the peripheral portion of the substrate along the line of magnetic force generated by the rotating magnetic field generating means and orthogonal to the axis of the exciting solenoid. Is given. As a result, the processing speed of the peripheral portion of the substrate having low plasma density is promoted, and more uniform etching processing or thin film formation on the substrate surface becomes possible.

〔Example〕

FIG. 1 shows an embodiment of an ECR plasma device constructed according to the present invention. The same members as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted. Two solenoids with a magnetic core 24 sandwiching the vacuum container 13 outside the vacuum container 13 near the substrate 24
Are opposed to each other. In addition, the axis common to the two solenoids 24 and the axis of the exciting solenoid 6 are also perpendicular to each other.
The solenoids 25 with magnetic cores are arranged to face each other. The arrangement of the two sets of solenoids 24, 25 is shown in the plan view of FIG.
A magnetic field whose direction rotates temporally in a plane orthogonal to the axis of the exciting solenoid 6 is generated by making alternating currents flowing through the two sets of solenoids and shifting the phases of the currents by 90 degrees. You can That is, two sets of solenoids connected to a two-phase AC power source whose voltage phases are shifted by 90 degrees form a rotating magnetic field generating means. This allows
The plasma generated in the plasma generation unit 17 is uniformly transferred to the substrate 11 arranged in the processing unit 19.

It is obvious that the rotating magnetic field can also be generated by three sets of solenoids that are connected to a three-phase AC power supply and are arranged in the same plane and are deviated by 60 degrees.

〔The invention's effect〕

As described above, according to the present invention, means for generating a microwave, means for transmitting the microwave, and means for transmitting the microwave are combined to introduce the microwave and gas supply means. The gas, which is sent through the plasma, is coaxially surrounded by a solenoid that generates lines of magnetic force that generate active atoms, molecules, or ions by plasmaizing the gas by the resonance effect with the microwave, and the phase is aligned with the lines of magnetic force. In an ECR plasma device equipped with a vacuum container in which a substrate whose surface is etched or a thin film is formed by various atoms, molecules or ions is arranged, and an exhaust means for exhausting the vacuum container, in the vicinity of the substrate. A line of magnetic force orthogonal to the axis of the solenoid is generated, and the line of magnetic force is rotated in a plane orthogonal to the axis of the solenoid. The rotating magnetic field generating means composed of two sets of sonoids connected to a two-phase AC power supply with a phase difference of 90 degrees or three sets of solenoids connected to a three-phase AC power supply with a phase difference of 60 degrees is used as the vacuum. Since it is provided on the outside of the container, plasma having a high density at the center is transferred from the plasma generating part in the vacuum container toward the substrate along the magnetic field lines generated by the exciting solenoid. In the plane orthogonal to the axis, a moving component that attempts to draw a spiral trajectory from the substrate center to the peripheral edge is given, so that the plasma in the central area with high density moves toward the peripheral edge of the substrate, The processing speed is accelerated, and more uniform etching processing or thin film formation on the substrate surface becomes possible. Moreover, the device configuration according to the present invention is possible without making any changes to the conventional device body,
There is an advantage that more uniform processing of the substrate surface can be performed easily.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an ECR plasma device according to an embodiment of the present invention, FIG. 2 is a plan view showing the arrangement of solenoids constituting a rotating magnetic field generating means around a vacuum container, and FIG. 3 is a conventional example. FIG. 3 is a vertical sectional view showing the configuration of an ECR plasma device. 1: Waveguide (microwave transmission means), 3, 13: Vacuum container, 4:
Gas supply means, 6: Excitation solenoid (solenoid), 7,1
7: Plasma generating part, 8: Magnetic field lines, 9,19: Processing part, 24, 25: Solenoid.

Claims (1)

[Claims] 1. A means for generating a microwave, a means for transmitting the microwave, and a gas which is coupled to the microwave transmitting means and into which the microwave is introduced and which is fed through a gas supply means. The active atoms, molecules or ions are coaxially surrounded by a solenoid that generates lines of magnetic force to generate active atoms, molecules or ions that are plasmatized by the resonance effect with the microwave and are transferred along the lines of magnetic force to the surface. In an ECR plasma device equipped with a vacuum container in which a substrate on which etching or a thin film is formed is arranged, and an ECR plasma device equipped with exhaust means for exhausting the vacuum container, a magnetic field line orthogonal to the axis of the solenoid is provided in the vicinity of the substrate. Generate and rotate this line of magnetic force in a plane orthogonal to the axis of the solenoid. A rotating magnetic field generating means constituted by two sets of solenoids connected to a power source or three sets of solenoids connected to a three-phase alternating current power source with a voltage shift of 60 degrees is provided outside the vacuum container. To
ECR plasma equipment.