JPS628521A - Apparatus for plasma treatment - Google Patents

Abstract

PURPOSE:To decrease damage that plasma gives to a substrate, by introducing microwaves for producing plasma and enabling the plasma to relatively change the treating position of a material. CONSTITUTION:A reaction gas is supplied into a reaction container 1 through a gas supply orifice 4 while, simultaneously, the container 1 is evacuated through an exhaust orifice 5 so as to set the pressure within the container at a low level. A solenoid coil 8 is energized so that a magnetron 6 is activated with a magnetic field formed in the reaction section 2. Microwaves produced thereby are guided through a waveguide 7 up to the end thereof, and this energy produced plasma within he reaction section 2. A table 3 is simultaneously moved along the X and Y directions in a plane so that a semiconductor substrate 10 is also moved in the plane. Thus, the position of the surface of the semiconductor substrate 10 is changed with respect to the plasma.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a plasma processing apparatus suitable for use in manufacturing semiconductor devices.

[Background technology]

RF discharge plasma etching is used as a technology for manufacturing semiconductor devices, especially for etching films on semiconductor substrates. For example, when etching organic films such as photoresists, a reaction is performed while maintaining an oxygen gas atmosphere. A technique is used in which an RF discharge is caused in a container to generate plasma in a reaction container, and this plasma energy is used to etch an organic film.

However, according to the inventor's experience, plasma etching using RF discharge can sometimes damage the semiconductor substrate, which is the base of the film to be etched, which hinders the production of highly reliable semiconductor devices. There is. Further, in a processing apparatus configured to simply bring plasma into contact with a sample, it is difficult to expect uniform and good plasma etching due to non-uniformity of the generated plasma.

Regarding the damage caused by plasma etching caused by RF discharge, see, for example, "IEICE Technical Research Report 5SD.
83-66, PI~''.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma etching apparatus that can reduce damage to a semiconductor substrate and perform etching processes uniformly and satisfactorily.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, by including a plasma generation section that guides microwaves to generate plasma, and a sample support section that can move the processing area of the sample relative to the plasma generation section, plasma generated by microwaves can be generated. Good plasma processing can be performed because the plasma causes less damage to the substrate and because the plasma is brought into uniform contact with the processing portion of the sample.

[Embodiment 1] FIG. 1 shows a first embodiment of the present invention. In the figure, reference numeral 1 denotes a reaction container, which is configured as a sealed container having a substantially hemispherical reaction section 2 at the top, and a semiconductor substrate 10 as a sample is placed on a table 3 inside. The reaction vessel 1 is provided with a gas supply port 4 and an exhaust port 5, so that the inside of the reaction vessel 1 can be set at a predetermined gas pressure. Further, the table 3 can be moved in the plane X and Y directions, and the plane position of the semiconductor substrate 10 placed thereon can be moved.

A tip of a waveguide 7 is disposed in the reaction section 2 of the reaction vessel 1 so as to cover it, and a magnetron 6 that generates microwaves is disposed at the base end of the waveguide 7. ing. Further, a solenoid coil 8 for generating a magnetic field within the reaction section 2 is arranged around the reaction section 2.

According to the above configuration, a reaction gas is supplied into the reaction container 1 from the gas supply port 4, while vacuum is drawn from the exhaust port 5 to maintain the inside of the container 1 at a low pressure (for example, 10 to 10-''T).

rr) and operate the magnetron 6 with the solenoid coil 8 energized to form a magnetic field within the reaction section 2, the generated microwaves will be guided through the waveguide 7 to its tip. This energy generates plasma within the reaction section 2.

At the same time, the table 3 moves in the plane XY directions to move the semiconductor substrate 10 in the plane and change the surface position of the semiconductor substrate 10 with respect to the plasma.

Therefore, according to this plasma processing apparatus, the semiconductor substrate 10 is heated by plasma generated by microwaves.
etching or other treatment on the surface of
Damage to the substrate can be reduced. In addition, since processing is performed while moving the semiconductor substrate 10 in the plane direction with the table 3 against the generated plasma, uniform processing can be performed over the entire surface of the substrate, achieving good plasma processing. can.

Note that the plane movement of the semiconductor substrate 10 by the table 3 may be either continuous movement or stepwise movement.

[Embodiment 2] FIG. 2 shows a second embodiment of the present invention, in which the same parts as in FIG. 1 are given the same reference numerals.

In this embodiment, the solenoid coil around the reaction section 2 of the reaction vessel 1 is omitted. Even if this solenoid coil is omitted, there is no effect on plasma generation using microwaves. Further, the table 3 provided in the reaction vessel 1 is fixed, and instead a movable mask 9 having a long and narrow slit 9a is arranged between the table 3 and the reaction section 2, and this mask 9 is moved in one direction during reaction processing. Or it is configured to move back and forth.

Also in this plasma processing apparatus, plasma is generated by microwaves in the reaction section 2, making it possible to perform processing with less damage, and by moving the mask 9, the slit 9a is moved relative to the surface of the semiconductor substrate 10. Since the surface of the substrate is sequentially brought into contact with the plasma, uniform treatment over the entire surface and desired treatment on a portion of the substrate can be achieved.

[Example 3] FIG. 3 shows yet another embodiment.

In this embodiment, the reaction vessel IA has a horizontally long shape, and a reaction space is defined by gate pulps 11 and 12 provided on both sides of the reaction vessel IA. In place of the table, a belt mechanism 13 is installed inside the reaction vessel IA, and the semiconductor substrate 10 is moved in one direction (from left to right in the illustrated case) by this belt mechanism 13. . Preparation chambers 14 and 15 are provided on both sides of each of the gate pulps 11 and 12, and semiconductor substrates 10 are transferred to and from the reaction space.

According to this configuration, it is possible to perform processing with less damage as in each of the above-mentioned embodiments, and since the semiconductor substrate 10 is continuously moved relative to the reaction section 2 by the belt mechanism 13, the substrate surface is evenly distributed. Not only processing but also multiple substrates can be processed with high efficiency.

[Embodiment 4] FIG. 4 shows an embodiment in which the present invention is applied to a horizontal reaction vessel 20, and in particular, an embodiment in which the present invention is applied to an apparatus for forming a thin oxide film on the surface of a semiconductor substrate.

In the figure, a gas supply port 21 is opened at one end of a cylindrical reaction vessel 20, and various gas sources, such as an HF gas source 22, a N2 gas source 23, and an Ot gas source 24 are connected to the gas supply port 21. It can be supplied into the reaction vessel 20.

Further, an exhaust port 25 is provided at the other end of the reaction vessel 20. A heater coil 26 is wound around the substantially right side of the reaction vessel 20 to heat the inside of the reaction vessel 20, while a reaction section 27 partially bulged on the left side.
is formed. In this reaction section 27, the tip of a waveguide 28 having a magnetron 29 at its base end is located. Note that the semiconductor substrate 10 as a sample is placed on the boat loader 30 and can be taken in and out of the reaction container 20 from the opening at the other end of the container. 31 is a removable lid for closing this opening.

According to this configuration, the surface of the semiconductor substrate 10 placed in the reaction container 20 is first etched by the HF gas supplied into the reaction container 20 and plasma generated by microwaves in the reaction section 27. Ru. At this time, the semiconductor substrate 10 is lifted by the boat loader 30.
The surface of each of the plurality of substrates 10 is uniformly etched. At this time, the damage caused by the plasma is small, as in each of the above embodiments.

After this etching, that is, the pretreatment for film formation, is completed, the substrate 10 is heated while filling the reaction container 20 with N2 gas.
Move to the right side of the container. Next, 02 gas is supplied into the container 20, the heater coil 26 is energized, and the substrate 1 is
Heat 0. As a result, an oxide film is formed on the surface of the semiconductor substrate 10.

[Example 5] FIG. 5 shows a modification of the embodiment shown in FIG.
In the figure, the same parts as in FIG. 4 are given the same reference numerals.

In this embodiment, a waveguide 28 to which a magnetron 29 is attached
The tip of the waveguide 28 is shaped to surround the reaction vessel 20, as shown in FIG. There is.

According to this configuration, plasma is generated by microwaves in the container at the location where the tip of the waveguide 28 is moved,
The surface of the substrate will be etched. therefore,
If the waveguide 28 is moved in the length direction of the reaction vessel 20 instead of moving the semiconductor substrate 10 and the boat loader 30, the location where plasma is generated is also moved and changed accordingly, and a plurality of substrates 10 Uniform etching can be performed on each surface. As before, plasma damage to the substrate can be reduced.

(Effects) (1) Plasma is generated by microwaves, so
Damage to the base of a semiconductor substrate or the like can be reduced.

(2) Since the sample is moved relative to the plasma, the surface of the sample can be uniformly plasma-treated.

(3) Since a waveguide provided with a magnetron may be disposed in relation to the reaction vessel, the structure of the processing apparatus can be simplified.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, various shapes of the reaction container other than those shown in the drawings can be used, and the configuration of the waveguide can also be changed as appropriate.

[Application field].

In the above explanation, the invention made by the present inventor was mainly applied to a plasma processing apparatus for etching semiconductor substrates, which is the background field of application of the invention, but the invention is not limited to this. It can also be applied as a plasma processing apparatus for forming.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the first embodiment of the present invention, FIG. 2 is a cross-sectional view of the second embodiment of the present invention, FIG. 3 is a cross-sectional view of the third embodiment of the present invention, and FIG. 5 is a cross-sectional view of the fourth embodiment of the invention, and FIG. 6 is a cross-sectional view of the fifth embodiment of the invention.
FIG. DESCRIPTION OF SYMBOLS 1... Reaction container, 2... Reaction part, 3... Table, 4... Gas supply port, 5... Gas exhaust port, 6...
Magnetron, 7... Waveguide, 8... Solenoid coil, 9... Moving mask, 10... Semiconductor substrate, 1
1.12...Gate pulp, 13...Belt mechanism,
14.15...Preliminary chamber, 20...Reaction container, 21.
...Gas supply port, 22-24...Gas source, 25...
Exhaust port, 26... Heater coil, 27... Reaction part,
28... Waveguide, 29... Magnetron, 30...
・Boat loader, 31...lid. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A plasma generating section that generates plasma by guiding microwaves, and a sample supporting section that moves a processing point of a sample relative to the plasma generating section. Plasma processing equipment. 2. The plasma processing apparatus according to claim 1, wherein the sample supporting section is movably provided with respect to the plasma generating section which is installed in a fixed state. 3. The plasma processing apparatus according to claim 1, wherein the plasma generating section is movably provided with respect to the sample support section installed in a fixed state. 4. A plasma generation section installed in a fixed state, a sample support section correspondingly installed in a fixed state, and a mask member that is disposed within this sample support section and is moved between the plasma generation section. A plasma processing apparatus according to claim 1.