JPH05326486A - Wet etching tank - Google Patents

Abstract

PURPOSE:To provide a wet etching tank in which an entire surface in the tank can be uniformly overflowed and an entire wafer can be uniformly etched. CONSTITUTION:Chemicals of an outer tank of an overflowing tank 11 are circulated by a pump 13. The chemicals passed through a filter 14 are fed to a plurality of branched tubes 18, and introduced from a discharge port 17 provided at a position directly under a disposing place of a cassette 15 in a bottom of an inner tank 10 thereinto. Thus, the port 17 of the chemicals is provided directly under the cassette 15 so that the chemicals flow uniformly between wafers 16 in the cassette 15 to etch the entire wafer 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet etching treatment tank for semiconductor manufacturing equipment.

[0002]

2. Description of the Related Art Conventionally, in a wet etching process, one cassette or a plurality of cassettes in which wafers are set are put in a tank which is circulated and filtered at the same time.

The conventional wet etching process will be described below. FIG. 2 is a schematic view of a conventional wet etching processing apparatus. 1 is an overflow tank, 2 is a bottom plate, 3 is a pump, 4 is a filter, 5 is a cassette, and 6 is a wafer.

The wet etching treatment tank configured as described above will be specifically described. The chemical solution in the outer tank of the overflow tank 1 is circulated to the inner tank through the filter 4 by the pump 3. The cassette 5 with the wafer 6 set in this inner tank is put on the bottom plate 2 and etched.

[0005]

However, in the conventional wet etching processing tank as described above, the overflow tank bottom plate 2 having a flat discharge port into the overflow tank 1 is used.
Since there is only one location in the center of the overflow tank 1, the liquid flow at the edge of the overflow tank 1 is less than that at the center, and the wafer 6 at the edge is less likely to be soaked in the chemical solution at the contact portion with the groove of the cassette 5 and is not etched. Had.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a wet etching treatment tank for making the flow of the chemical liquid in the overflow tank uniform.

[0007]

In order to achieve this object, a wet etching treatment tank of the present invention comprises a first tank capable of processing a plurality of cassettes and a second tank provided outside the first tank. A tank, a first pipe connected to the second tank, and a second pipe branched from the pipe into a plurality of pipes through a filter.
And the discharge ports of the second pipe are connected to the positions of the plurality of cassettes.

[0008]

In addition, since the circulation pipe to the overflow tank is branched and a plurality of discharge ports are provided directly below the cassette, the chemical liquid can flow uniformly to the wafer in the cassette, and the wafer can be uniformly etched. .

[0009]

EXAMPLE FIG. 1 is a schematic view of a wet etching treatment tank in which a circulation pipe is branched in one embodiment of the present invention.

In FIG. 1, 10 is an inner tank, 11 is an overflow tank formed of quartz or a fluorine compound capable of treating a plurality of cassettes, 12 is a bottom plate for mounting the cassette, and 13 is a chemical solution of the overflow tank 11. A pump for circulating, 14 is a filter for circulating and filtering the chemical solution in the overflow tank 11, 15 is a cassette made of quartz or a fluorine compound, 16 is a wafer, 1
Reference numeral 7 is a discharge port where the chemical solution in the overflow tank 11 is circulated and filtered and enters the inner tank 10, and 18 is a circulation pipe.

The chemical solution in the outer tank of the overflow tank 11 is circulated in the direction of arrow A by the pump 13. Filter 14
The circulation pipe 18 after flowing through the above is branched and the discharge port 17 is provided directly below the cassette 15. By providing the chemical solution discharge port 17 just below the cassette 15, the chemical solution can flow uniformly to the wafer 16 in the cassette 15, and the entire surface of the wafer 16 can be etched. In particular, since the overflow tank 11 for processing the wafer 16 having a large diameter of 6 inches or more is large, the effect is great.

In the conventional example, when the nitride was etched by using high temperature phosphoric acid, the residue of the nitride was found on the wafer 16 at the end of the inner tank 10 at the contact portion with the groove of the cassette 15. Thus, the wafer 16 in the inner tank 10
Was difficult to uniformly etch, but by using the apparatus according to the present invention, there was no etching residue and the entire surface of the wafer 16 could be uniformly etched.

[0013]

As described above, according to the wet processing apparatus of the present invention, the circulation pipe is branched and the discharge port is provided directly below the cassette so that the chemical solution uniformly flows to the wafer in the cassette and the entire surface of the wafer is processed. Can be uniformly etched.

[Brief description of drawings]

FIG. 1 is a schematic view of a wet etching treatment tank in one embodiment of the present invention.

FIG. 2 is a schematic view of a conventional wet etching processing apparatus.

[Explanation of symbols]

 10 Inner Tank 11 Overflow Tank 12 Bottom Plate 13 Pump 14 Filter 15 Cassette 16 Wafer 17 Discharge Port 18 Piping

Claims (1)

[Claims] 1. A first tank capable of processing a plurality of cassettes, a second tank provided outside the first tank, a first pipe connected to the second tank, and the pipe. And a second pipe that is branched into a plurality of parts via a filter, and the discharge port of the second pipe is connected to the positions of the plurality of cassettes, respectively.