JPH1060673A - Etching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an etching device provided with a shower head in which the amt. of gas to be blown-off can be regulated. SOLUTION: This etching device 10 is provided with a shower head 18 composed of many gas blow-off pores piercing a planar upper electrode 14. In this case, the surface of the upper electrode is provided with a shutter apparatus 24 having an opening in which the opening diameter is freely contractible and expandable, and the amt. of gas to be blown-off and the gas flow can be regulated. The shutter apparatus 24 is composed of plural plasma resistant movable blades arranged partially piled up to the peripheral direction of the opening so as to form the opening on the center, in the case the opening diameter is contracted, the movable blades progress toward the center of the opening with each other, and in the case the opening diameter is expanded, the movable blades retreat from the center of the opening with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an etching apparatus, and more particularly, to an etching apparatus capable of controlling an amount of gas blown out of a shower head and a gas flow to meet various etching process conditions. Things.

[0002]

2. Description of the Related Art A conventional etching apparatus 30 equipped with a shower head has a process chamber 1 as shown in FIG.
2 includes a plate-shaped upper electrode 14 and a lower electrode 16 on which the wafer W is placed so as to face the upper electrode 14. The shower head 18 includes a large number of gas outlets 18 that pass through the upper electrode 14 and have a constant opening diameter. Therefore, in the conventional etching apparatus 30, as long as the gas introduction pressure is constant, the gas blowing amount is substantially constant, and the gas flow distribution in the process chamber 12 is also substantially constant. In FIG. 4, reference numeral 20 denotes a gas inlet and 22 denotes a gas outlet. By the way, in the wafer etching process, C
The etching conditions differ depending on the etching target such as a VD oxide film, a Si nitride film, and a tungsten film, and it is often necessary to change the gas blowing amount.

[0003]

However, when the etching conditions are changed, if the conventional etching apparatus having the above-described shower head is used, it is not possible to change the gas blowing amount of the shower head. To
The process chamber 12 must be opened to remove the upper electrode 14 itself and be replaced with another upper electrode with a showerhead having an opening through which a predetermined amount of gas can be blown out. In this case, the work efficiency of the etching process is reduced, and it is difficult to improve the productivity. Therefore, there has been a demand for an etching apparatus provided with a shower head capable of changing the amount of gas blown out. In order to meet such a demand, an object of the present invention is to provide an etching apparatus having a shower head capable of adjusting a gas blowing amount.

[0004]

In order to achieve the above object, an etching apparatus according to the present invention is an etching apparatus having a shower head comprising a plurality of gas blowing holes penetrating a plate-like upper electrode. A shutter device having an opening capable of freely reducing and enlarging the diameter is provided on the upper electrode so that the amount of gas blown out from the shower head and the gas flow can be controlled.

In the present invention, by providing a shutter device having a variable opening mechanism on a shower head and adjusting the opening of the shutter device, it is possible to adjust the amount of gas blown out and to control the gas flow in the process chamber. Like that. The shutter device has a plasma-resistant material, so that it may be exposed to plasma during etching.
For example, the same material as the upper electrode or a ceramic such as SiC is used. The etching apparatus according to the present invention can be applied without limitation as long as it is an etching apparatus having a shower head, and can be suitably applied to, for example, an ECR plasma etching apparatus and a parallel plate type plasma etching apparatus.

In a preferred embodiment of the present invention, the shutter device comprises a plurality of plasma-resistant movable blades arranged so as to partially overlap in the circumferential direction of the opening so as to form the opening at the center. When the diameter is reduced, the movable blades advance toward the center of the opening, and when the diameter is increased, the movable blades retract from the center of the opening. The shutter device of the embodiment has the same configuration as the diaphragm mechanism attached to the camera shutter, adjusts the central opening area, and closes a part of the total number of gas outlets of the shower head. Thus, the amount of gas blowout can be adjusted and the flow of gas in the process chamber can be controlled.

[0007]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment This embodiment is one of the embodiments of the etching apparatus according to the present invention, and FIG. 1 is a schematic diagram showing the configuration of the etching apparatus of this embodiment. The etching apparatus 10 of the present embodiment
As shown in FIG. 1, a shutter device 24 is provided on the upper electrode plate 14 in addition to the configuration of the conventional etching device 30 shown in FIG.

The shutter device 24 has substantially the same configuration as an aperture mechanism attached to a camera shutter.
As shown in (a), a plurality of movable blades 28 partially overlapped in the circumferential direction of the opening 26 so as to form the opening 26 at the center, and the movable blades 28 are mutually centered on the opening 26. Forward and vice versa
6 has a driving device (not shown) for driving to retreat from the center. The driving device may be a mechanical type using a spring mechanism or an electric type using an electric motor. Because the movable blade 28 is exposed to the plasma during the process,
From a material resistant to plasma, for example, the same material as the upper electrode,
Alternatively, it is made of ceramic such as SiC.

In the shutter device 24, the movable blade 2
8 are driven by the driving device and mutually advance toward the center of the opening 26, the opening diameter of the opening 26 is reduced as shown in FIG. When the movable blades 28 are driven by the driving device and recede from the center of the opening 26, the diameter of the opening 26 is reduced.
As shown in FIG.

In the present etching apparatus 10, when the opening of the shutter device 24 is enlarged, the process gas flows downward from the entire surface of the shower head 18, as shown in FIG. Conversely, when the opening of the shutter device 24 is reduced, the opening at the peripheral portion of the shower head 18 is closed, and the process gas flows downward only from the opening at the central portion, as shown in FIG. . As described above, by controlling the opening diameter of the shutter device 24 and adjusting the gas blowing amount and the gas flow distribution, the control of the etching becomes easy, and the uniformity of the etching rate in the wafer surface,
The uniformity of the line width and the uniformity of the shape of the wiring can be improved.

By using the present etching apparatus 10, etching can be performed on a wafer in accordance with process requirements. For example, when blanket tungsten is etched back, an isotropic etching method using SF ₆ / Ar as a reaction gas is applied. Therefore, it is better to introduce SF ₆ / Ar only from the central portion of the shower head 18. This is desirable from the viewpoint of increasing the rate and reducing the loading effect. Further, when etching an adhesion layer such as a TiN film / Ti film, low pressure anisotropic etching using Cl ₂ is required, so that gas is introduced from the entire surface of the shower head 18 to the wafer. desirable. In addition, by using the present etching apparatus 10, etching at the time of forming an oxide film-based contact hole that requires a higher etching rate and shape control, a lower etching rate, and an in-plane uniformity of the etching are required. A wide variety of etching requirements such as wall etching and nitride film etching can be met.

[0012]

According to the structure of the present invention, by providing a shutter device having an opening capable of freely reducing and enlarging the opening diameter on the shower head of the etching device on the upper electrode, the gas from the shower head can be reduced. The blowing amount and the gas flow can be controlled. By controlling the amount of gas blown out from the shower head and the gas flow, it is possible to easily respond to differences in etching conditions, that is, differences in film structure, film type, etc., to achieve uniform etching rate in the wafer surface, and line width. Uniformity and shape uniformity can be improved. Further, by using the etching apparatus according to the present invention, the etching conditions can be easily changed according to the process requirements without replacing the upper electrode as in the related art, so that the etching productivity can be improved. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of an etching apparatus of the present embodiment.

FIGS. 2A and 2B are plan views illustrating the operation of the shutter device, respectively.

FIGS. 3A and 3B are schematic diagrams illustrating the etching controllability of the etching apparatus of the present embodiment.

FIG. 4 is a schematic diagram showing a configuration of a conventional etching apparatus having a shower head.

[Explanation of symbols]

10 etching apparatus of this embodiment, 12 process chamber, 14 upper electrode, 16 lower electrode, 18
... shower head, 20 ... gas inlet, 22 ... gas outlet, 24 ... shutter device, 26 ... opening, 2
8 ... Movable blade.

Claims (2)

[Claims] 1. An etching apparatus having a shower head comprising a plurality of gas blowing holes penetrating a plate-shaped upper electrode, wherein a shutter device having an opening capable of freely reducing and expanding an opening diameter is provided on the upper electrode. An etching apparatus wherein the amount of gas blown from a shower head and the flow of gas can be controlled. 2. A shutter device comprising: a plurality of plasma-resistant movable blades arranged so as to partially overlap each other in a circumferential direction of an opening so as to form an opening at a center; 2. The etching apparatus according to claim 1, wherein the movable blades mutually move toward the center of the opening, and when the diameter of the opening is enlarged, the movable blades mutually recede from the center of the opening. 3.