JP2002100620A - Plasma-producing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma-producing apparatus capable of processing a wafer at a high speed without contamination. SOLUTION: A gas is jetted onto a surface of the wafer by means of a discharge chamber 7, a magnetron 1 to produce plasma inside of the discharge chamber, a wave guide, solenoids 10, 11, a quartz plate 9 to supply microwave to the discharge chamber 7, a space to reserve a gas inside of the quartz plate 9, and a quartz plate 18 having a gas-supplying outlet 17 of the one fourth of a maximum diameter of the discharge chamber or smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave plasma generating apparatus, and more particularly to a microwave plasma generating apparatus suitable for speeding up processing of a sample such as a semiconductor element substrate by utilizing microwave plasma. Related to the device.

[0002]

2. Description of the Related Art Conventional microwave generation techniques include, for example,
NIKKEI MICRODEVICE
S) August 1990, page 88, as shown in FIG. 5, having a plasma generation chamber in a microwave-propagating waveguide,
Plasma is generated in the waveguide by the action of an external magnetic field and a microwave electric field. Then, the semiconductor wafer substrate is processed using the plasma.

[0003]

In the above prior art, since the introduction of the process gas is set independently of the exhaustion of the reaction by-products, the reaction by-products often adhere to the wafer, and the wafer is contaminated. And a reduction in processing speed has been a problem.

An object of the present invention is to provide a plasma generation apparatus capable of performing high-speed wafer processing without contamination.

[0005]

In order to achieve the above object, according to the present invention, the supply port of the microwave generating gas is opposed to the wafer and is concentrated at the center.

[0006] Since the generated gas flows through the region where the reaction by-products are formed just above the wafer, the reaction by-products are easily exhausted.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS.
This will be described with reference to FIG. FIG. 1 is a block diagram of a magnetic field type microwave plasma processing apparatus. 2 and 3 are a sectional view and a plan view of the invention. The discharge chamber 1 is a magnetron, and is a microwave oscillation source. 3 to 6 are waveguides. Here, 3 is a rectangular waveguide, 4 is a circular waveguide, and 6 is a tapered tube. The discharge chamber 7 is made of, for example, high-purity aluminum or the like, and also serves as a waveguide. 8 is a vacuum chamber. Reference numeral 9 denotes a quartz plate for supplying microwaves to the discharge chamber 7. Reference numerals 10 and 11 denote solenoid coils, which apply a magnetic field to the discharge chamber 7. Reference numeral 12 denotes a sample stage on which a semiconductor element substrate (hereinafter, wafer) 14 is mounted, to which a bias power supply, for example, an RF power supply 13 can be connected. Reference numeral 16 denotes a vacuum pump system for depressurizing and exhausting the inside of the discharge chamber 7 and the inside of the vacuum chamber 8. Reference numeral 15 denotes a gas supply system for supplying a gas for performing processes such as etching and film formation into the discharge chamber 7. Inside the quartz plate 9 of the discharge chamber 7,
A quartz plate 18 having a gas supply port 17 is provided, and the quartz plate 9 is provided.
A space 19 for storing gas is provided between the quartz plate 18 and the space. The distance between the quartz plate 9 and the quartz 18 is set to a small distance so that plasma does not enter. A passage 20 is provided in the side wall 7 ′ of the discharge chamber 7, and the passage 20 communicates with the space 19 and the gas supply system 15. The discharge chamber 7 is provided with a gas outlet 21 and communicates with the vacuum chamber 8. The size of the gas supply port 17 is set to 1/4 or less of the diameter of the maximum discharge chamber.

In FIG. 1, circular waveguide 5, tapered tube 6,
The sample mounting surfaces of the quartz plate 9 and the sample stage 12 have a coaxial central axis (not shown). The placement of the wafer 14 on the sample placement surface of the sample stage 12 is performed using, for example, a mechanical pressing force or an electrostatic attraction force. In addition, the sample table 12
Includes, for example, a temperature control unit (not shown), and the wafer 1 mounted on the sample mounting surface of the sample stage 12 by this unit.
The temperature of 2 is adjusted to a predetermined temperature.

The magnetron is attached to the rectangular waveguide 3 as in the prior art, and oscillates, for example, a microwave of 2.45 GHz. On the other hand, a magnetic field distribution is given to the inside of the discharge chamber 7 by the solenoid coils 10 and 11 as shown in FIG. 1 (b), and an ECR point (875 gauss) is set near the center of the discharge chamber. .

The processing gas passes through the passage 20 from the supply system 15, accumulates in the space 19, and is introduced into the discharge chamber from the gas supply port 17. The gas is dissociated in the plasma in the discharge chamber 7 and partially becomes a radical, and processes the surface of the wafer 12. By this surface treatment, reaction by-products scatter in the discharge chamber 7. The gas flow in the discharge chamber 7 is
To the outlet 21. Therefore, the reaction by-products that have entered the stream ride on the gas stream and are discarded from the outlet 21. However, reaction by-products tend to accumulate on the source wafer 12. According to this embodiment, since the gas supply port is narrowed to the center of the discharge chamber 7, the gas descends from above along the central axis, and the wafer 1
After colliding with 2, the reaction by-products are efficiently exhausted from the surface of the wafer 12 to the discharge port because the reaction by-products are directed to the discharge port through the surface of the wafer 12.

FIG. 4 is a plan view showing another embodiment of the present invention. The gas supply port 17 provided in the quartz plate 18 is composed of a plurality of small holes 17a. The area where the holes are formed is set to be 1/4 or less of the maximum diameter of the discharge chamber. With such a configuration, there is an effect that the speed of the gas from the gas supply port 17 becomes uniform at each supply port.

[0012]

According to the present invention, reaction by-products generated by wafer processing can be efficiently exhausted, and the processing can be speeded up.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration and a magnetic field distribution of a magnetic field type microwave plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of one embodiment of the present invention.

FIG. 3 is a plan view of one embodiment of the present invention.

FIG. 4 is a plan view of another embodiment of the present invention.

[Explanation of symbols]

Reference numeral 7: discharge chamber, 9: quartz plate, 12: sample stage, 14: wafer, 17: gas supply port, 18: quartz plate, 19: space, 2
0: passage, 21: outlet.

Continued on the front page (72) Inventor Yutaka Kakehi 502 Kandachi-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratories, Hitachi, Ltd. (72) Inventor Naoyuki Tamura 794 Higashi-Toyoi, Kudamatsu-shi, Yamaguchi Pref. F term (reference) 4K030 CA04 CA12 EA05 FA02 KA30 5F004 AA14 BA14 BB14 BB28 BC03 BD04 5F045 AA08 BB15 DP03 DQ10 EB02 EE20 EF05 EF20 EH17

Claims (2)

[Claims] A vacuum vessel provided with a means for reducing the pressure in the vessel; a processing gas supply means for supplying a processing gas to the vacuum vessel; a data base for placing a wafer in the vacuum vessel; and a plasma generator. And a processing gas path for injecting the processing gas supplied from the processing gas supply means into the container is formed in a lateral direction in an upper portion of the container avoiding an electromagnetic field formed by the coil, and a supply port is provided. Is disposed on the vacuum vessel wall directly facing the wafer, and the inner wall of the vacuum vessel in the vicinity of the supply port in the direction of the data base from the supply port is formed to have a substantially constant diameter. A plasma generator characterized in that it is narrowed to a position near a central axis of a container. 2. A vacuum vessel provided with means for reducing the pressure inside the vessel, a processing gas supply means for supplying a processing gas to the vacuum vessel, a data base on which a wafer is placed in the vacuum vessel, and a plasma generator. A flow path through which the processing gas supplied from the processing gas supply means passes, and a supply port of the processing gas to the vacuum container is directly opposed to the wafer. Disposed on the wall surface of the vacuum vessel, the inner wall of the vacuum vessel in the vicinity of the supply port in the direction of the data base from the supply port is formed to have a substantially constant diameter,
The diameter of the supply port is narrowed to the central axis of the vacuum vessel.