JPS6254442A - Dry etching process - Google Patents

Abstract

PURPOSE:To improve the yield by a method wherein the first electrode to be loaded with a wafer, the second electrode to be provided on the first electrode and a feed pipe to feed gas to the second electrode are provided while the first and the second gas blow-off parts with a plurality of gas blow-off holes are provided on the second electrode. CONSTITUTION:The flow rate of gas blown off from a plurality of blow-off holes 4a formed at the central part of an electrode 5 is controlled by a flow rate controller 9a while the other flow rate of gas blown off from a plurality of blow-off holes 4b formed on the peripheral part of electrode 5 is controlled by another flow rate controller 9b. When the gas distribution density in the central part of wafer 2 is low and that in the peripheral part of wafer 2 is high correspondingly to the distribution status on the surface of wafer 2, the flow rate of gas blown off from a plurality of blow-off holes 4a formed on the central part of the electrode 5 is increased more than the other flow rate of gas blown off from a plurality of blow-off holes 4b formed at the peripheral part of electrode 5 by the flow rate controller 9a. Through these procedures, the gas distribution on the surface of wafer 2 can be equalized to stabilize the etching process, improving the yield thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a dry etching apparatus, and in particular, when performing gas etching on a wafer, a so-called shower electrode disposed inside the reaction vessel is used to conduct etching from the outside of the reaction vessel. The present invention relates to an improvement in a gas supply mechanism for supplying gas to a large number of gas blow-off holes formed in a shower electrode in order to supply gas into a reaction vessel.

[Prior Art] Conventionally, an example of an electrode disposed in a reaction vessel when performing gas etching on a wafer is a shower electrode 20 shown in FIG.

This shower electrode 20 has a gas supply hole 21 formed inside its support portion 22 that communicates with a gas supply pipe outside the reaction vessel.

Inside the electrode 20, a large number of blow-off holes 23 are formed which communicate with the supply holes 21 and blow out gas toward the side of the electrode 20, and the gas blown out from the blow-off holes 23 is It is supplied to the surface of the wafer 25 placed on the lower electrode 24 below the electrode 20 .

As a measure to uniformly distribute the gas on the surface of the wafer 25 during the etching process, the shower electrode is provided with a plurality of blow-off holes 23 having different diameters and forming intervals.

[Problems to be Solved] However, in such a conventional dry etching apparatus using a shower core, there is only one gas supply hole that communicates with the gas supply pipe outside the reaction vessel. Since gas is supplied to all the blow-off holes from this one supply hole, as a measure to uniformly distribute the gas on the wafer surface and perform the etching process, multiple shower electrodes with different diameters and formation intervals are used. Even if blow holes are provided, there is a problem in that the gas distribution on the wafer surface cannot be made uniform due to the relationship with the gas supply pressure.
There is a problem in that if the size of the wafer changes, the configuration of the plurality of blowing holes must be changed accordingly.

[1°l aspect of the invention] An object of the present invention is to solve the above-mentioned conventional problems, and to increase the etching process by 11" by making the gas distribution uniform on the surface of the wafer, thereby improving the product yield. It is an object of the present invention to provide a dry etching device that can handle holes of any size, such as Ueno\.

[L stage for solving the problem] The first stage of this invention to achieve the above 11 objectives is as follows:
A first electrode on which a wafer is placed, a second electrode provided above the first electrode, and a supply pipe for supplying gas to the second electrode, the second electrode being , a first one having a plurality of gas blowing holes. The dry etching apparatus includes a second gas blowing section.

[Operation] The dry etching apparatus constructed in this way supplies the first electrode to the second electrode from the supply pipe. Gas is supplied to the second gas blowing section, and the first. The gas supplied to the second gas outlet is
The gas is blown toward the second electrode from the plurality of blow-off holes of the first gas blow-off part and the plurality of blow-off holes of the second gas blow-off part.

This results in an even gas distribution on the wafer surface.
As a result, stable enching processing can be performed.

[Embodiment Code] An embodiment of the dry etching apparatus according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the dry etching apparatus according to the present invention.
This shows an example.

This dry etching apparatus l includes a first electrode 3 on which a wafer 2 is placed, and a plurality of gas blowing holes 4a + 4.
The first with b. Second gas blowing section 5a.

5b.

The second electrode 5 is provided on one side of the first electrode 3, and is entirely formed into a disk 1.

The second electrode 5 has two gas supply holes 7a and 7b formed inside its support portion 8, which communicate with two gas supply pipes 6a and 6b outside the reaction vessel, respectively. .

Now, inside the second electrode 5, there are a number of blow-off holes 4at4b for blowing out gas toward the side of the second electrode 5. Second gas blowing portions 5a and 5b are formed.

The first gas blowing section 5a is formed in the center of the electrode 5, has a plurality of blowing holes 4a, and communicates with the supply hole 7a.

Further, the second gas blowing section 5b is formed around the electrode 5, has a plurality of blowing holes 4b, and communicates with the supply hole 7b.

Thus, the plurality of blow-off holes 4a formed in the central part of the electrode 5 are supplied with gas from one gas supply pipe 6a through the supply hole 7a, and the plurality of blow-off holes 4a formed in the central part of the electrode 5 are The plurality of blowout holes 4b receive gas supply from the other gas supply pipe 6b via the supply hole 7b.

As shown in FIG. 2, the second gas blowing section 5b communicates with the circular first gas blowing section 5a in a ring shape.
is formed around.

Further, the two gas supply pipes 6 aw 8 b each have a flow for adjusting the supply pressure of the gas supplied to the gas supply holes 7 a + 7 b, and adjusting the flow;
11 adjustment devices 9 a t 9 b are provided.

The dry etching apparatus l configured in this way has an electrode 5
Mr and Lit of the gas blown out from the plurality of blow-off holes 4a formed in the central part of the electrode 5 are adjusted by the flow rate adjustment device 9a, and the flow 1 of the gas blown out from the plurality of blow-off holes 4b formed in the peripheral part of the electrode 5 is adjusted. The flow rate is adjusted by the adjustment device 9b.

Then, depending on the gas distribution situation on the surface of the wafer 2, for example, if the gas distribution density in the central part of the wafer 2 is low and the gas distribution density in the peripheral part of the wafer 2 is high, the flow rate adjustment device 9a The flow rate of the gas blown out from the plurality of blow-off holes 4a formed in the central part of the electrode 5 is made larger than the flow rate m of the gas blown out from the plurality of blow-off holes 4b formed in the peripheral part of the electrode 5.

In this way, the flow rate regulators 9a + 9b,
The gas flow fil blown out from the plurality of blow-off holes 4a formed in the central part of the electrode 5 and the gas flow 14 blown out from the plurality of blow-off holes 4b formed in the peripheral part of the electrode 5 are relatively different. By doing so, the gas distribution on the surface of the wafer 2 is made uniform.

Although the 1-1 embodiment has been described above, 1. The arrangement position of the second gas blowing part does not necessarily have to be the central part and the peripheral part of the second electrode. It can be changed depending on the shape of the second electrode, the arrangement position of the gas supply pipe, etc.

[Efficacy of invention! ! ] As is clear from the explanation in I- below, the dry etching apparatus of the present invention includes a first electrode on which a wafer is placed, a second electrode provided above the first electrode, and a second electrode provided above the first electrode. and a supply pipe for supplying gas to the second electrode, the second electrode having a plurality of gas blowing holes. Equipped with a second gas blowing section, the gas distribution on the wafer surface becomes uniform and stable etching processing can be performed, improving product yield and making it possible to handle wafers of different sizes. be able to.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the dry etching apparatus according to the present invention, FIG. 2 is a plan view of the second electrode, and FIG. Kushita - Parts plan. i... Dry etching device, 2-... Wafer, 4a... Gas blowing hole of the first gas blowing part, 4
b-... Gas blowing hole of the second gas blowing part, 5-...
・・Second electrode, 5 a ・−First gas blowing part, 5
b--Second gas blowing section, 8a, 6b-Gas supply pipe, 9a, 9b...Flow j, l adjustment device.

Claims (2)

[Claims] (1) The second electrode includes a first electrode on which a wafer is placed, a second electrode provided above the first electrode, and a supply pipe that supplies gas to the second electrode. A dry etching apparatus characterized in that the electrode includes first and second gas blowing portions having a plurality of gas blowing holes. (2) Supply pipes are provided corresponding to the first and second gas blowing parts, each supply pipe is equipped with a flow rate adjustment device that adjusts the flow rate of gas, and the first gas blowing part is connected to the second electrode. Claim 1, wherein the second gas blowing section is arranged in the central part of the first gas blowing section, and the second gas blowing section is arranged on both sides of the first gas blowing section.
Dry etching equipment described in Section 1.