JPH04171934A - Wet type processing equipment for semiconductor - Google Patents

Abstract

PURPOSE:To prevent captured dust from flowing out again on account of the pulsation of a filter, by installing a buffering equipment for absorbing the pulsation between a pump and a filter which is generated from the pump. CONSTITUTION:The title equipment is constituted of a processing tank 6 for processing a semiconductor substrate and an N2 pressurizing type buffering equipment for absorbing pulsation generated from a circulation pump 1. Chemical liquid in the processing tank is sent to a buffer tank 7 by the pump 1. The chemical liquid in the buffer tank 7 is returned to the processing tank 6 through a filter 3, thereby performing circulation filtering. The buffer tank 7 always monitors the pressure change of the chemical liquid sent from the pump 1 with a pressure control equipment 4, and controls the pressure of N2 to be supplied to the buffer tank to be always constant. Thereby the chemical liquid is supplied to a filter mesh with a constant pressure. Hence it can be prevented that captured dust flows out again on account of the pulsation of the filter mesh. A check valve 2 prevents the chemical liquid from inversely flowing from the buffer tank 7 to the pump 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wet processing apparatus for semiconductor substrates, and more particularly to a chemical circulation type wet processing apparatus for etching and cleaning used in the manufacture of semiconductor devices.

[Conventional technology]

Conventionally, in this type of wet processing apparatus, as shown in FIG. 3, circulation filtration has been performed by returning chemical liquid to the processing tank through a filter 2 provided immediately after the pump by a chemical pump 1 in a processing tank 3.

[Problem to be solved by the invention]

In the conventional semiconductor wet processing equipment described above, the filter is placed immediately after the pump for circulating the chemical solution, so the pulsation of the pump is directly received by the filter mesh, and due to the deformation of the mesh, it is captured once by the filter mesh. There is a drawback that the dust is re-flowed and the dust that returns to the processing tank is reattached when the semiconductor substrate is pulled up.

In recent years, with the miniaturization of integrated circuits, re-adhesion of dust to processed semiconductor substrates has become a major hindrance to semiconductor manufacturing.

An object of the present invention is to prevent trapped dust from flowing out again due to pulsation of the filter, thereby improving filtration speed and filtration ability, effectively removing dust during semiconductor substrate processing, and removing semiconductor substrates from the processing tank. An object of the present invention is to provide a semiconductor wet processing device that can reduce re-adhesion of dust during lifting.

[Means to solve the problem]

The circulating wet treatment device of the present invention provides a buffer device between the pump for circulating the chemical solution through the filter and the filter for filtering it, which absorbs the pulsations generated from the pump, so that the pressure is always constant. The feature is that the chemical solution is sent to the filter side to prevent pulsation of the filter mesh.

As a buffer device for absorbing pulsation, the purpose can be achieved by inserting a N2 pressurized buffer tank between the pump for circulating the chemical solution and the filter, or by using a buffer tank using a torque motor.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a schematic diagram of an embodiment of the present invention. In this example,
It consists of a processing tank 6 for processing semiconductor substrates and an N2 pressurized buffer device that absorbs pulsations generated from the circulation pump 1.
The chemical solution in the processing tank is sent to the buffer tank 7 by the pump 1, and the chemical solution in the buffer tank 7 is returned to the processing tank 6 through the filter 3, thereby performing circulation filtering.

The buffer tank 7 constantly monitors pressure fluctuations of the chemical solution sent by the pump 1 by the pressure control device 4, and controls the N2 pressure applied to the buffer tank to always be constant. As a result, the chemical solution is always supplied to the filter mesh at a constant pressure, so it is possible to prevent trapped dust from flowing out again due to pulsation of the filter mesh.

The check valve 2 is provided to prevent the chemical solution from flowing back into the pump 1 from the buffer tank '7.

FIG. 4 is a graph comparing the amount of dust reduction in a chemical solution due to circulation filtering with that of the prior art. Compared to the conventional technology, the present invention can improve the dust removal speed by about twice and the amount of dust in the final chemical solution by about 1/3.

FIG. 2 is a schematic diagram of the configuration of another embodiment of the present invention. This embodiment has a pump 1 and a filter 2 similar to the first embodiment.
A buffer tank is provided between the pump and the pump to absorb the pulsation of the pump.

The buffer tank of this embodiment has a structure in which the chemical liquid in the tank is sent to the filter 3 by the pressure of the piston 5, and the pressure fluctuations applied to the chemical liquid in the buffer tank by the pump 1 are detected by the torque motor 4. The pressure applied to the chemical solution through the piston 5 is always kept constant. As a result, the chemical solution is always supplied to the filter mesh at a constant pressure.
Prevents trapped dust from flowing out again due to pulsation of the filter mesh.

Compared to the first embodiment, this embodiment does not use N2 gas, so there are no problems such as leakage.

〔Effect of the invention〕

As explained above, the present invention prevents the trapped dust from flowing out again due to the pulsation of the filter by providing a buffer device between the pump and the filter to absorb the pulsation generated by the pump. This improves filtration speed and filtration ability, effectively removes dust during semiconductor substrate processing, and reduces re-adhesion of dust when semiconductor substrates are pulled up from the processing tank.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the configuration of one embodiment of the present invention, Fig. 2 is a schematic diagram of the configuration of another embodiment of the present invention, Fig. 3 is a sectional view of the configuration of the prior art, and Fig. 4 is a chemical solution by circulation filtration. It is a graph comparing the amount of dust reduction inside the conventional example and the present example. 1... Pump, 2... Check valve, 3... Filter, 4... Pressure control device (torque motor), 5...
Viston, 6...processing tank, 7...buffer tank.

Claims (1)

[Claims] 1. A semiconductor wet processing device having a circulation filtering mechanism includes a buffer device that suppresses pulsation of the filter mesh that occurs when a chemical solution is circulated, and prevents dust once captured by the filter mesh from flowing out. A semiconductor wet processing device characterized by: 2. The method according to claim 1, characterized in that an N_2 pressurized buffer tank is provided between the pump for circulating the chemical solution and the filter as a buffer device for suppressing the pulsation of the filter mesh that occurs when the chemical solution is circulated. Semiconductor wet processing equipment. 3. Claim 1 characterized in that a buffer tank using a torque motor is provided between the pump for circulating the chemical solution and the filter as a buffer device for suppressing pulsation of the filter mesh that occurs when circulating the chemical solution. The semiconductor wet processing apparatus described above.