JPH0621040A - Jet type wet etching device - Google Patents

Abstract

PURPOSE:To prevent attaching of particle and to improve processing accuracy by always supplying fresh chemical to a wafer surface and by attracting a rear by a conductive chuck when wet-etching a semiconductor device of a large diameter to be fined. CONSTITUTION:A wafer 3 is held by a conductive vacuum chuck 1 with a surface downward and jet of etching chemical is sprayed to a surface through a nozzle 4 from below. Thereby, it is possible to prevent attaching of particle and fine particle (mist) of chemical and creeping of particle from a rear and to improve processing accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet type wet etching apparatus.

[0002]

2. Description of the Related Art A conventional wet etching apparatus is shown in FIG.
As shown in, the wafer 3 contained in the carrier 11 is immersed in the etching bath. The chemical solution is the inner tank 1
2 overflows to the outer tank 13 and drains 15
From the inner tank 12 through the filter 6 by the pump 7.
It circulates on the way back to and filtering is done. The wafer 3 and the carrier 11 are washed with water and dried after etching for a predetermined time.

FIG. 4 shows a spinner type wet etching apparatus. In this case, the wafer 3 is 100 to 30
00r. p. m. Rotate about a degree, from the top surface of the wafer 3,
A chemical solution is applied through the nozzle 14. Chemicals drain 25
From the tank to the tank 19 and reused.

[0004]

However, in the above-mentioned immersion type wet etching apparatus, dust is adsorbed by charging the cassette for holding the wafer or the wafer itself.

Particles attached to the back surface of another wafer also attach to the front surface.

On the other hand, even in the case of the spinner type etching apparatus, there are problems such as the attachment of falling particles, and the fine particles (mist) of the chemical liquid scattered after the etching attach to the surface of the wafer to form spots. .

The present invention has been made in view of the above-mentioned conventional circumstances. Therefore, the object of the present invention is to provide a novel jet-type wet etching apparatus capable of solving the above-mentioned problems inherent in the prior art. To provide.

[0008]

In order to achieve the above object, a jet type wet etching apparatus according to the present invention comprises a conductive vacuum check for vacuum-adsorbing the back surface of a wafer and a wafer front surface facing downward. And a pump for spraying the etching solution only on the surface of the wafer.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be specifically described with reference to the drawings for each of its preferred embodiments.

FIG. 1 is a partial cross-sectional schematic structural view showing a first embodiment of a jet type wet etching apparatus according to the present invention.

Referring to FIG. 1, a wafer 3 is held inside a chamber 8 by a conductive vacuum chuck 1 with its surface facing downward. The vacuum chuck 1 is grounded to prevent charging. The chemical liquid is sprayed from below onto this structure by the pump 7.

After being filtered by the filter 6, the chemical solution is ejected from the nozzle 4 and sprayed on the surface of the wafer 3 through the clear stream plate 2. The flow straightening plate 2 is provided so that the etching liquid uniformly hits the surface of the wafer, and a jet flow hits the wafer 3 through holes (not shown) formed in the flow straightening plate 2. The shape of the current plate 2 is determined according to the viscosity of the etching liquid, the flow rate of the jet flow, and the shape of the chamber 8.

After hitting the wafer 3, the chemical liquid is drained from the drain 5 and returned to the tank 9 for reuse.

Since the surface of the wafer 3 is held downward, the particles are less likely to adhere to the surface, and the fine particles (mist) of the chemical solution are less likely to adhere to the surface. Further, it is possible to prevent particles from wrapping around from the back surface of the wafer.

The number of particles deposited by the apparatus of the present invention is shown in FIG. 5 in comparison with the conventional example. By etching from the lower side by the jet flow, a new chemical liquid from the nozzle 4 is constantly applied to the surface of the wafer, which can reduce particles and improve the uniformity of the amount of etching on the surface of the wafer.

Further, since the jet flow hits the surface of the wafer perpendicularly, the side etch amount can be reduced and the in-plane uniformity can be improved.

FIG. 2 is a partial cross sectional schematic diagram showing a second embodiment according to the present invention.

Referring to FIG. 2, in the case of the second embodiment of the present invention, the motor 1 for rotating the conductive vacuum chuck 1 is used.
0 is provided.

In the case of the second embodiment, the wafer 3 is moved by the motor 10 to 100 to 3000 rpm. p. m. By rotating with, the in-plane uniformity can be further improved.

[0020]

As described above, according to the present invention,
By removing the charge by the conductive vacuum chuck and performing jet etching with the surface facing downward, it is possible to prevent particles from adhering and improve the processing accuracy.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional schematic configuration diagram showing a first embodiment according to the present invention.

FIG. 2 is a partial cross-sectional schematic configuration diagram showing a second embodiment according to the present invention.

FIG. 3 is a schematic diagram of a conventional immersion type wet etching apparatus.

FIG. 4 is a schematic diagram of a conventional spinner type etching apparatus.

FIG. 5 is a diagram showing the number of adhered particles according to the present invention in comparison with a conventional example.

[Explanation of symbols]

 1 ... Conductive vacuum chuck 2 ... Rectifier plate 3 ... Wafer 4 ... Nozzle 5, 15, 25 ... Drain 6 ... Filter 7 ... Pump 8 ... Chamber 9, 19 ... Tank 10 ... Motor 11 ... Carrier 12 ... Inner tank 13 ... Outside Tank

Claims (1)

[Claims] 1. A conductive vacuum chuck for vacuum-adsorbing a back surface of a wafer, a wafer holder for holding the wafer with the front surface of the wafer facing downward, and a pump for spraying the etching solution onto the front surface of the wafer. A jet-type wet etching apparatus, which sprays onto the surface of a wafer in a jet shape and performs etching.