JP3067398B2 - Jet type wet etching equipment - Google Patents

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 (1), the wafer 3 placed in the carrier 11 is immersed in the etching bath. Chemical solution is in inner tank 1
2 overflows into the outer tank 13 and drains 15
From the inner tank 12 through the filter 6 by the pump 7.
It circulates on the path returning to and is filtered. After etching the wafer 3 and the carrier 11 for a predetermined time, the wafer 3 and the carrier 11 are washed and dried.

FIG. 4 shows a spinner type wet etching apparatus. In this case, the wafer 3 is 100 to 30
00r. p. m. From the upper surface of the wafer 3,
The chemical is applied through the nozzle 14. Chemical solution drain 25
From the tank 19 to be reused.

[0004]

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

[0005] Particles adhered to the back surface of another wafer adhere to the front surface.

On the other hand, even in the case of a spinner type etching apparatus, there are problems such as adhesion of particles falling, and fine particles (mist) of a chemical solution scattered after etching adhering to the surface of the wafer to form a stain. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and an 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. Is to provide.

[0008]

In order to achieve the above object, a nozzle for jetting an etching solution into a chamber according to the present invention is provided at a distance from the nozzle and below the position of the nozzle outlet. A jet-type wet etching apparatus with a drain hole for draining the etching solution is a vacuum potential that vacuum-adsorbs the back surface of the wafer to the outside of the chamber.
A conductive vacuum check electrically connected to the , a wafer holder holding the wafer with the wafer surface facing down,
A pump for spraying an etching solution only on the surface of the wafer is provided, and the etching solution that has fallen on the wafer surface is discharged through the drain hole.

[0009]

Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic sectional 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 by a conductive vacuum chuck 1 inside a chamber 8 with its surface facing downward. The vacuum chuck 1 is grounded to prevent charging. A chemical is sprayed on the structure from below by the pump 7.

After the chemical solution is filtered by the filter 6,
Ejected from the nozzle 4, is blown through the settling Nagareban 2 on the surface of the wafer 3. The current plate 2 is provided so that the etching solution uniformly hits the surface of the wafer.
Through a hole (not shown) drilled in the
Hit. The shape of the current plate 2 is determined according to the viscosity of the etching solution, the flow rate of the jet, and the shape of the chamber 8.

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

Since the surface of the wafer 3 is held downward, adhesion of particles due to falling of particles is small, and adhesion of fine particles (mist) of the chemical liquid to the surface is also reduced. Further, it is possible to prevent particles from wrapping around from the back surface of the wafer.

FIG. 5 shows the number of particles attached by the apparatus of the present invention in comparison with the conventional example. By performing etching from below by the jet flow, a new chemical solution from the nozzle 4 is constantly applied to the surface of the wafer, thereby reducing particles and improving the uniformity of the etching amount of the wafer surface.

Further, since the jet flows perpendicularly to the surface of the wafer, the amount of side etching can be reduced and the in-plane uniformity can be improved.

FIG. 2 is a schematic sectional view showing a second embodiment of the present invention.

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

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

[0020]

As described above, according to the present invention,
The effect of removing electricity by the conductive vacuum chuck and the effect of jet-type etching with the surface facing downward can prevent particles from adhering and improve processing accuracy.

[Brief description of the drawings]

FIG. 1 is a schematic partial cross-sectional view showing a first embodiment of the present invention.

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

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

FIG. 4 is a schematic view 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]

 DESCRIPTION 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 (2)

(57) [Claims] 1. A jet flow type comprising: a nozzle for jetting an etching solution into a chamber; and a drain hole for discharging an etching solution provided below the nozzle and away from the nozzle. In a wet etching apparatus, a wafer is fixed outside the chamber, and is grounded.
An etching solution that includes an electrically connected conductive vacuum chuck, sprays an etching solution onto the wafer surface in a jet-flow state with the surface of the wafer fixed downward, etches, and drops the etching solution while hitting the wafer surface. Is discharged through the drain hole. 2. The jet-type wet etching apparatus according to claim 1, further comprising a current plate between the nozzle and a surface of the wafer.