JPH0555172A - Dry etching apparatus - Google Patents

Abstract

PURPOSE:To uniform alize etching speed in a surface. CONSTITUTION:A hollow section 11a of an opposite electrode 6 is partitioned into a plurality of diffusing chambers 13a, 13b, 13c, opening/closing of branch tubes 3, 4, 5 for introducing gas into the chambers 13a, 13b, 13c and gas valves are controlled, and a gas jet hole 12 is selected to jet the gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry etching apparatus having a parallel plate type electrode structure.

[0002]

2. Description of the Related Art FIGS. 3 (a) and 3 (b) show a conventional dry etching apparatus, and FIG.
(B) is a figure which shows the structure of a counter electrode. Conventionally, this type of dry etching apparatus has, for example, as shown in FIG. 3, a chamber 10 having a gas introduction pipe 1, and a counter electrode 6 and a lower electrode 9 arranged in the chamber 10. .. Further, the lower electrode 9 has a wafer 8 which is an object to be etched mounted thereon, and the counter electrode 6 which is an upper electrode has a hollow portion 11 for diffusing a gas introduced from the gas introduction pipe 1 and is provided on the opposite surface. Is a gas outlet 12 that blows out gas
Was opened.

Usually, when a wafer is etched by this dry etching apparatus, a high frequency voltage is applied to the counter electrode 6, the gas introduced is plasma-ionized, and the surface of the wafer 8 is etched by the impact energy of the ions. It was Then, various measures have been taken to supply the gas to the counter electrode 6 or to diffuse the gas so that the wafer surface is uniformly etched.

[0004]

4 (a) and 4 (b).
3A is a plan view of the wafer for explaining the result when the wafer is etched by the dry etching apparatus of FIG. 3, and FIG. In the conventional dry etching apparatus described above, the gas introduction system passage is fixed, and it is difficult to change the distribution of gas concentration in the chamber.
Therefore, as shown in FIG. 4B, when a plurality of etching conditions are used in one apparatus, it is difficult to make the etching rate in the wafer plane the same for all these conditions.

An object of the present invention is to provide a dry etching apparatus capable of making the in-plane etching rate uniform regardless of the etching conditions in order to solve such a problem.

[0006]

According to the dry etching apparatus of the present invention, a hollow portion of a counter electrode facing an object to be etched is partitioned into a plurality of chambers, and a plurality of surfaces of the partitioned chambers facing the object to be etched are partitioned. The gas outlet holes are formed, and each of the chambers is provided with a gas inlet pipe, a gas valve attached in the middle of the gas inlet pipe, and a gas valve controller for controlling the opening and closing of these gas valves. It is characterized by blowing out gas.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

1 (a) and 1 (b) show an embodiment of the dry etching apparatus of the present invention. FIG. 1 (a) is a schematic diagram showing the overall structure, and FIG. 1 (b) is a diagram showing the structure of a counter electrode. is there.
In this dry etching apparatus, as shown in FIG.
Branch into three branch pipes 3, 4 and 5 and attach gas valves 2, 2a and 2b to the respective branch pipes 3, 4 and 5
A gas valve controller 7 for controlling these gas valves 2, 2a and 2b is provided. The hollow portion 11a of the counter electrode 6 is partitioned into diffusion chambers 13a and 13c for introducing gas independently from the branch pipes 3, 4 and 5, respectively. Then, the diffusion chambers 13a, 13b and 13
Gas blowing holes 12 for blowing each gas are formed in the surface of c facing the lower electrode 9.

Next, the operation of this dry etching apparatus will be described. In advance, decompress the chamber 10,
Gas is ejected from the ejection holes 12 of the diffusion chambers 13a, 13b and 13c. Next, a gas sensor measures the gas concentration distribution between the counter electrode 6a and the lower electrode 9. Then, each valve 2, 2a and 3a is adjusted by the gas valve controller 7 so that the gas concentration distribution becomes uniform,
The flow rate of the gas introduced into the diffusion chambers 13a, 13b and 13c is adjusted. Next, a high frequency voltage is applied to the counter electrode 6a to etch the wafer 8.

In this way, the counter electrode 6a is partitioned into a plurality of diffusion chambers, and the gas flow rate of the gas supplied to the diffusion chambers is controlled by the gas valve controller to control the opening and closing of the gas valve to select the blowout holes 12 on the surface of the counter electrode 6a. By ejecting the gas, the gas concentration distribution in the space between the electrodes is changed, so that the etching rate in the wafer surface can be made uniform.

2 (a) and 2 (b) are views for explaining the result when the wafer is etched by the dry etching apparatus of FIG. 1, (a) is a plan view of the wafer, and (b) is each part of the wafer. It is a graph which shows an etching rate.
By the way, when the wafer was etched by the dry etching apparatus of the present invention, as shown in FIG. 2, the result that the variation of the etching rate within the wafer surface was about 3% was obtained.

[0012]

As described above, according to the dry etching apparatus of the present invention, the internal structure of the counter electrode is divided into the diffusion chambers for introducing a plurality of gases, and the gas blowing holes are independently formed in the diffusion classroom to form the diffusion chamber. There is an effect that the etching rate in the wafer surface can be made uniform by adjusting the flow rate of the gas supplied to the substrate, controlling the amount of gas blown out from each diffusion chamber, and changing the gas concentration distribution.

[Brief description of drawings]

1A and 1B show an embodiment of a dry etching apparatus of the present invention, FIG. 1A is a schematic diagram showing the entire configuration, and FIG. 1B is a diagram showing the structure of a counter electrode.

2A is a plan view of the wafer, and FIG. 2B is a graph showing an etching rate in each part of the wafer, for explaining a result when the wafer is etched by the dry etching apparatus of FIG.

FIG. 3 shows an example of a conventional dry etching apparatus,
(A) is the schematic which shows the whole structure, (b) is a figure which shows the structure of a counter electrode.

4A is a plan view of the wafer, and FIG. 4B is a graph showing an etching rate in each part of the wafer, for explaining the result when the wafer is etched by the dry etching apparatus of FIG.

[Explanation of symbols]

 1 Gas introduction pipe 2, 2a, 2b Gas valve 3, 4, 5 Branch pipe 6, 6a Counter electrode 7 Gas valve controller 8 Wafer 9 Lower electrode 10 Chamber 11, 11a Hollow part 12 Gas blowout hole 13a, 13b, 13c Diffusion chamber

Claims (1)

[Claims] 1. A hollow portion of a counter electrode facing an object to be etched is partitioned into a plurality of chambers, and a plurality of gas blowing holes are formed on a surface of the partitioned chamber, the surface facing the object to be etched. Dry etching characterized by comprising a gas introduction pipe connected to the gas introduction pipe, a gas valve attached in the middle of the gas introduction pipe, and a gas valve controller for controlling opening / closing of the gas valve, and selecting the gas blowing hole to blow out gas. apparatus.