JPH0719772B2 - Reactive ion etching equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is directed to a reactive ion etching apparatus used for microfabrication of a semiconductor device, and more particularly, to uniformly control the flow of a reactive gas during etching. The present invention relates to an etching device.

[Conventional technology]

FIG. 2 is a perspective sectional view of a conventional reactive etching apparatus. In FIG. 2, an anode electrode 3 is provided in an upper part of a cylindrical vacuum container 11, a reactive gas introducing pipe 4 is connected to the anode electrode 3, and the anode electrode 3 is grounded by a conductor. A circular cathode electrode 2 is provided so as to face the electrode 3, and a semiconductor wafer 10 to be etched is placed on the circular cathode electrode 2. Then, the cathode 2 is connected to a high frequency power source 9 by a conductive wire, a high frequency voltage is applied between the cathode 2 and the anode 3, and the reactive gas introduced by the gas introducing pipe 4 is ionized, so that the wafer 10
Is etched. At the same time, the gas in the container 11 is exhausted from the exhaust port 12 formed in the lower part of the side surface of the container 11 through the exhaust pipe 6 having the exhaust pump 7.

[Problems to be solved by the invention]

The reactive gas exhaust port of the conventional reactive ion etching apparatus described above has a fixed exhaust port asymmetrically fixed to the wafer in the cylindrical etching chamber. Is not uniform with respect to the wafer and cannot control the flow of the reactive gas during the etching process, so that a desired etching shape cannot be obtained, and a stable high yield cannot be obtained. There is.

[Means for solving problems]

In the reactive ion etching apparatus according to the present invention, the cylindrical vacuum container is doubled, and the exhaust ports are provided in two or more concentric bands between the inner etching chamber and the outer exhaust preparatory chamber. With a controllable throttle valve,
An exhaust pipe is connected to the bottom of the exhaust preparatory chamber to make the gas flow uniform with respect to the semiconductor wafer to be etched in the etching chamber. In addition, since the flow of gas can be controlled continuously by the throttle valve, the reactive radicals and ions that contribute to etching become uniform in the wafer surface, and the density distribution can be controlled. An etching shape can be obtained.

〔Example〕

 Next, the present invention will be described with reference to examples.

FIG. 1 is a perspective sectional view of an embodiment of the present invention. In FIG. 1, an inner etching chamber 1a is provided in a cylindrical vacuum container 1.
And the outer exhaust spare chamber 1b are doubled, and the cathode 2 in which the semiconductor wafer to be etched is described is arranged in the lower part of the etching chamber 1a. Also, facing the cathode 2, the gas introduction pipe is provided. An anode 3 to which 4 is connected is arranged. Then, a high-frequency voltage is applied between the anode 3 and the cathode 2 by the high-frequency power source 9, and the reactive gas introduced by the gas introduction pipe 4 is ionized,
Contributes to the etching of the wafer 10. Then, the upper, middle, and lower 3 which are concentrically provided between the outer auxiliary spare chamber
The introduced gas flows from the stage exhaust ports 5, 5, 5 to the outside exhaust prechamber 1b, and the reactive gas is exhausted from the bottom exhaust port of the exhaust prechamber 1b through the exhaust pipe 6 having the exhaust pump 7. Incidentally. A slot valve 8 is provided in the exhaust spare chamber 1b,
The flow of reactive gas is freely controlled.

〔The invention's effect〕

As described above, in the reactive ion etching device according to the present invention, the cylindrical etching chamber vacuum container is provided with two or more exhaust ports in the form of concentric bands, so that the flow of the reactive gas becomes uniform. Furthermore, by providing a throttle valve that can be independently controlled in the pipe that connects each exhaust pump and exhaust port, it is possible to continuously control the flow of reactive gas while etching is in progress and contribute to etching. Since the reactive radicals and ions to be formed become uniform in the plane of the wafer and the density distribution can be controlled, a desired etching shape can be obtained, and a stable high yield can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective sectional view of an embodiment of the present invention, and FIG. 2 is a perspective sectional view of a reactive ion etching apparatus using a conventional technique. 1,11 ... Vacuum container, 2 ... Cathode, 3 ... Anode,
4 ... Gas introduction pipe, 5 ... Exhaust port, 6 ... Exhaust pipe, 7 ...
... Exhaust pump, 8 ... Throttle valve, 9 ... High frequency power supply, 10 ... Semiconductor wafer.

Claims (1)

[Claims] 1. A cathode electrode on which a wafer to be processed is placed and an anode electrode facing the wafer are arranged in a cylindrical etching chamber container into which a reactive gas is introduced, and the cathode electrode and the anode electrode. In the reactive ion etching device for etching the wafer by applying a voltage between the etching chamber container and the etching chamber container, a vacuum container is provided outside the etching chamber container to form an exhaust preliminary chamber, and the etching chamber The container has two or more concentric belt-shaped exhaust ports, and an independently controllable throttle valve is provided between the vacuum chamber and the outside of each etching chamber container divided by the exhaust ports. A reactive ion etching apparatus characterized in that an exhaust pipe having an exhaust pump is connected to a bottom portion.