JPH05258894A - Microwave plasma processing device - Google Patents

Abstract

PURPOSE:To perform the uniform, high-speed plasma process by generating uniform, high-density plasma in a discharge tube. CONSTITUTION:A plasma processing device utilizing microwaves is provided with a TE12 resonator 6 at the transmission section of microwaves, the ratio between the diameter of a discharge block 1b generating plasma and the diameter of the TE12 resonator 6 is set to 0.345, the axis of the TE12 resonator 6 is matched with the axis of the discharge block 1b, and the TE12 resonator 6 and the discharge block 1b are arranged in this order in the advance direction of microwaves. Microwaves in the TE11 mode are stably fed into the discharge block 1b.

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.

[0002]

2. Description of the Related Art A conventional apparatus is disclosed, for example, in Japanese Patent Laid-Open No. 59-1.
As described in JP-A-03340 and JP-A-64-25420, a structure in which a dome-shaped discharge tube made of quartz is provided as a part of a decompressible processing chamber inside an enlarged waveguide Was becoming.

[0003]

The above-mentioned prior art does not consider the mode of the microwave propagating in the discharge tube which is a part of the processing chamber, and the plasma is generated uniformly and efficiently. There was a problem that not.

According to the present invention, a circular TE ₁₁ mode microwave is stably supplied into a discharge tube which is a part of a processing chamber to generate a uniform and high-density plasma, thereby performing a uniform and high-speed plasma processing. It is an object of the present invention to provide a microwave plasma processing apparatus capable of performing the above.

[0005]

In order to achieve the above-mentioned object, a TE ₁₂ resonator is provided in a microwave transmission section, and a diameter of a discharge tube which is a part of a processing chamber and a diameter of the TE ₁₂ resonator are different from each other. The ratio is set to 0.345, the axis of the TE ₁₂ resonator is aligned with the axis of the discharge tube, and the TE ₁₂ resonator and the discharge tube are arranged in this order in the direction of microwave propagation, whereby TE
It is designed to stably supply _12- mode microwaves.

[0006]

The microwaves other than the circular TE ₁₂ mode are cut inside the TE ₁₂ resonator provided in the microwave transmission section, and only the circular TE ₁₂ mode microwaves are present. Among the electric lines of force of the circular TE ₁₂ mode, the electric lines of force within a circle of 0.345 times the outer diameter from the center coincide with the electric lines of force of the circular TE ₁₁ mode. Therefore, the ratio of the diameter of the discharge tube to the diameter of the TE ₁₂ resonator is set to 0.345, the axis of the TE ₁₂ resonator is aligned with the axis of the discharge tube, and the TE _{12 is} moved in the microwave traveling direction.
By arranging the resonator and the discharge tube in this order, the TE ₁₂ resonator acts so as to stably supply the TE ₁₁ mode microwave into the discharge tube. On the other hand, the microwave introduced into the discharge tube acts on the external magnetic field generated in the axial direction to generate electron cyclotron resonance, thereby generating plasma. In addition, of the electric fields of the microwave, the electric field in the direction perpendicular to the magnetic field participates in the electron cyclotron resonance, so in order to generate a high-density plasma, TE is generated in the discharge tube.
It is more desirable to supply mode microwaves. Therefore,
By using a TE ₁₂ resonator, a circular TE
_{Since 11-} mode microwaves can be supplied stably, uniform and high-density plasma can be generated, and uniform and high-speed plasma processing becomes possible.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows a magnetic field microwave dry etching apparatus according to a first embodiment of the present invention. After depressurizing the inside of the processing chamber 1 defined by the container 1a, the discharge block 1b and the quartz window 2 by a vacuum exhaust device (not shown), an etching gas is introduced into the processing chamber 1 by a gas supply device (not shown). , Adjust to desired pressure. The processing chamber 1 is in the magnetic field region generated by the coil 3. A microwave of, for example, 2.45 GHz generated by the magnetron 4 propagates through the waveguides 5a and 5b, and the TE ₁₂ resonator 6 formed of a space surrounded by the waveguide 5c and the discharge block 1b is generated. After passing through the quartz window 2, it enters the discharge block 1b where plasma is generated. The material 8 placed on the sample table 7 is etched by the plasma generated by the microwave. Further, in order to control the etching shape of the material 8 to be processed, a high frequency power source 10 is connected to the sample stage 7 via a matching unit 9 and a high frequency voltage is applied.

Inside the TE ₁₂ resonator 6 provided in the microwave transmission section, microwaves other than the circular TE ₁₂ mode are cut off, and only the circular TE ₁₂ mode microwaves are present. Among the electric lines of force of the circular TE ₁₂ mode, the electric lines of force within a circle of 0.345 times the outer diameter from the center coincide with the electric lines of force of the circular TE ₁₁ mode. Therefore, the discharge block 1b
The ratio of the diameter φA of the TE ₁₂ resonator 6 to the diameter φB of the TE ₁₂ resonator 6 is set to 0.345, the axis of the TE ₁₂ resonator 6 and the axis of the discharge block 1b are aligned, and the TE ₁₂ resonator 6 and the TE ₁₂ resonator 6 are arranged in the traveling direction of the microwave. By arranging these in the order of the discharge block 1b, circular TE ₁₁ mode microwaves are stably supplied into the discharge block 1b. On the other hand, the microwave introduced into the discharge block 1b acts on the external magnetic field generated in the axial direction,
A plasma is generated by causing electron cyclotron resonance. In addition, of the electric fields of microwaves, the electric field in the direction perpendicular to the magnetic field participates in electron cyclotron resonance.
It is preferable to supply the TE mode microwave in b. In the present invention, by using the TE ₁₂ resonator, it is possible to stably supply a circular TE ₁₁ mode microwave having a wide region in which the electric field distribution is uniform in the discharge block 1b that generates plasma. The plasma can be generated, and uniform and high-speed plasma processing becomes possible.

According to this embodiment, since the circular TE ₁₁ mode microwave can be stably supplied into the discharge block 1b, there is an effect that uniform and high-speed plasma processing becomes possible.

In the first embodiment, the ratio of the diameter φA of the discharge block 1b to the diameter φB of the TE ₁₂ resonator 6 is 0.3.
However, even if the ratio of φA to φB is in the range of 0.1 to 0.6, microwaves propagating in the discharge block 1b are mostly in the circular TE ₁₁ mode. Almost the same effect can be obtained.

A second embodiment of the present invention will be described with reference to FIG. In this embodiment, a donut-shaped disk iris 11 made of a conductive material such as aluminum is provided on the discharge block 1b and the quartz window 2, and the iris 11 and the waveguide 5c constitute a TE ₁₂ resonator 6. did. By changing the inner diameter of the iris 11, the discharge block 1b, which is a load
Since microwaves can be efficiently supplied to the plasma inside, plasma with higher density can be generated. Therefore, in this embodiment, in addition to the effect of the first embodiment, there is an effect that plasma processing can be performed at a higher speed.

A third embodiment of the present invention will be described with reference to FIG. In this embodiment, the TE ₁₂ resonator 6 is manufactured independently and has the same effect as that of the first embodiment.

A fourth embodiment of the present invention will be described with reference to FIG. In this embodiment, the TE ₁₂ resonator 6 is provided between the coil 3a and the coil 3b. The microwave emitted from the magnetron 4 passes through the waveguides 5 a and 5 b and the tapered waveguide 12 and is introduced into the TE ₁₂ resonator 6. In the present embodiment, in addition to the effect of the first embodiment, a large TE ₁₂ resonator 6 can be provided, and therefore the inner diameter φA of the discharge block 1b in which plasma is generated can be increased, which is large. There is an effect that the material to be processed 8 having an area can be uniformly processed.

A fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the TE ₁₂ resonator 6 is provided on the coil 3. Also in this embodiment, since the inner diameter φA of the discharge block 1b can be increased, the same effect as that of the fourth embodiment can be obtained.

Although the magnetic field dry etching apparatus has been described in each of the above-described embodiments, similar effects can be obtained in other plasma processing apparatuses such as a dry etching apparatus utilizing microwaves, a plasma CVD apparatus, and an ashing apparatus. Be done.

[0016]

According to the present invention, since circular TE ₁₁ mode microwaves can be stably supplied into the discharge block for generating plasma, uniform and high-density plasma is generated, and uniform and high-speed plasma processing is performed. There is an effect that it becomes possible.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a processing chamber portion of a magnetic field microwave dry etching apparatus according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a processing chamber portion of a magnetic field microwave dry etching apparatus according to a second embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view of a processing chamber portion of a magnetic field microwave dry etching apparatus according to a third embodiment of the present invention.

FIG. 4 is a vertical sectional view of a processing chamber portion of a magnetic field microwave dry etching apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a vertical sectional view of a processing chamber portion of a magnetic field microwave dry etching apparatus according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 ... processing chamber, 1b ... discharge block, 2 ... a quartz window, 3 ... coil, 4 ... magnetron, 5 ... waveguide, 6 ... TE ₁₂ resonators, 7 ... sample stage 8 ... workpiece, 9 ... matching Vessel, 10 ... High frequency power source, 11 ... Iris, 12 ... Tapered waveguide.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // C23C 14/34 8414-4K H01L 21/31 C

Claims (4)

[Claims] 1. A plasma processing apparatus comprising a plasma generating apparatus using microwaves, a processing chamber capable of decompressing, a gas supply apparatus, and an evacuation apparatus, and a T is provided at a microwave transmission portion.
A microwave plasma processing apparatus provided with an E ₁₂ resonator. 2. The axis of the TE ₁₂ resonator is aligned with the axis of a discharge tube which is a part of a processing chamber capable of decompressing, and the TE ₁₂ resonator and the discharge tube are arranged in this order in the traveling direction of microwaves. The microwave plasma processing apparatus according to claim 1, wherein: 3. The microwave plasma processing apparatus according to claim 2, wherein the ratio of the diameter of the discharge tube and the diameter of the TE ₁₂ resonator is 0.1 to 0.6. 4. The microwave plasma processing apparatus according to claim 2, having a structure capable of stably supplying a circular TE ₁₁ mode microwave of a discharge tube which is a part of a processing chamber capable of decompressing.