JPS62195130A - Wet type semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To markedly reduce the dirt contained in the chemical solution for surface processing a wafer by a method wherein all the chemical solution in a processing vessel wherein a cassette containing a wafer to be surface-processed is entered is drained from the bottom of vessel to be cleaned up and stored in a storage tank and then returned to the processing vessel again. CONSTITUTION:In order to reduce the dirt contained in a chemical solution, a valve 7 is opened to drain the chemical solution in a processing vessel 2 into a filter 4 through a circulating pipe 6 for cleaning up and then all the chemical solution in the processing vessel 2 stored in a storage tank 8 is returned to the processing vessel 2 again by a pump 5. Through these procedures, the dirt contained in the chemical solution is reduced without fail by collectively filtering the chemical solution in the processing vessel 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a wet semiconductor manufacturing apparatus used in wet process 1, which is one step of a semiconductor manufacturing process.

[Conventional technology]

FIG. 2 is a block diagram schematically showing an example of a circulation system of a conventional wet semiconductor manufacturing apparatus, and FIG. 3 is a perspective view of a chemical tank 1 and a processing tank 2. In these figures, 1 is a chemical tank, and 2 is a processing tank in which a cassette containing wafers to be surface-treated is stored.When the chemical tank 1 and the processing tank 2 are empty, the chemical supply valve 3 The chemical solution is supplied to fill the processing tank 2 to about half of the chemical solution tank 1. Reference numeral 4 denotes a filter for removing dust from the chemical solution, and 5 indicates a pump that sends the chemical solution from the chemical solution tank 1 into the processing tank 2 from the bottom of the processing tank 2 through the filter 4 via a circulating vibro which connects each part.

Next, the operation of the circulation system of a conventional wet semiconductor manufacturing apparatus will be explained.

First, the chemical solution overflowing from the treatment tank 2 accumulates in the chemical solution tank 1, passes through the circulation vibro, flows into the pump 5, passes through the circulation vibro, and is sent to the filter 4 by the pump 5, where dirt is removed. Thereafter, it is returned to the processing tank 2 from the bottom of the processing tank 2. Conventionally, this circulation operation was performed constantly.

[Problem that the invention seeks to solve]

In the conventional circulation system configured as described above, as shown in Fig. 4, turbulent flow occurs in the processing tank 2, and the garbage in the turbulent flow does not leave the processing tank 2 for a long time. There was a problem that the number of garbage in 2 did not decrease.

The present invention was made to solve these problems, and an object of the present invention is to provide a wet semiconductor manufacturing apparatus that can reliably reduce the amount of dust in a processing tank.

[Means for solving problems]

In the wet semiconductor manufacturing apparatus according to the present invention, all of the chemical solution in the processing tank is taken out from the bottom of the processing tank, stored in a storage tank, and purified and returned to the processing tank again.

[Effect]

In this invention, during filtering, all of the chemical solution in the processing tank is transferred to a storage tank, and then purified and returned to the processing tank again, so that dust in the chemical solution is reliably removed.

[Embodiment] FIG. 1 is a schematic block diagram of a wet semiconductor manufacturing apparatus showing an embodiment of the present invention. The same reference numerals as in FIG. 2 indicate the same parts, and the explanation thereof will be omitted.

In FIG. 1, 7 is a valve provided in the middle of the circulation vibro, 8 is a storage tank in which the valve 7 is opened to purify and take out the chemical solution in the processing tank 2 through the filter 4, and is stored there; 9b is a waste liquid valve.

In such a configuration, in order to reduce dust in the chemical solution, by opening the valve 7, the chemical solution in the processing tank 2 flows through the circulation vibro to the filter 4, is purified through the filter 4, and is processed. After all of the chemical solution in the tank 2 is stored in the storage tank 8, it may be returned to the processing tank 2 by the pump 5.

In this way, by collectively filtering the chemical liquid in the processing tank 2, the amount of dust in the chemical liquid is reliably reduced.

Although the filter 4 is placed in front of the storage tank 8 in the embodiment shown in ``-'', the same effect can be obtained even if the filter 4 is placed in front of or after the pump 5.

In addition, in order to transfer the chemical solution from the storage tank 8 to the processing tank 2,
Although the pump 5 is used, the same effect can be obtained by making the storage tank 8 a closed type and supplying pressure with dry air or the like.

〔Effect of the invention〕

As explained above, the present invention has a system in which all the chemical solution in the processing tank containing the cassette containing the wafers to be surface-treated is stored in the storage tank from the bottom of the processing tank, and is purified and returned to the processing tank again. As a result, the amount of dust in the chemical solution used to treat the wafer surface is significantly reduced, which greatly reduces the incidence of wafer defects caused by dust adhering to the backside of the wafer, and improves wafer manufacturing yield. It has the advantage of being measurable.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of a wet-type semiconductor manufacturing apparatus showing an embodiment of the present invention, and FIGS. 2 and 3 are schematic block diagrams showing an example of a circulation system of a conventional wet-type semiconductor manufacturing apparatus, and a chemical tank and processing. FIG. 4, a perspective view of the tank, is a diagram illustrating the turbulent flow of the chemical solution in the processing tank. In the figure, 1 is a chemical tank, 2 is a processing tank, 3 is a chemical supply valve, 4 is a filter, 5 is a pump, 6 is a circulation pipe, and 7
is a valve, 8 is a storage tank, and 9 is a waste liquid valve. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In an apparatus that performs surface treatment of a wafer by immersing a cassette containing a wafer in a processing tank provided in a chemical tank and filled with a chemical solution, all of the chemical solution in the processing tank is removed from the bottom of the processing tank. A wet semiconductor manufacturing apparatus comprising: a storage tank for taking out and storing chemical liquid; a means for returning the chemical liquid in the storage tank to the processing tank; and a filter for purifying the chemical liquid returned to the processing tank.