JPH04278530A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To eliminate ununiformity of etching amount which is generated in a wafer surface while chemical liquid in a treating vessel is replaced with pure water. CONSTITUTION:A chemical liquid.pure water compounding part pipe 8 which mixes chemical liquid and pure water to be supplied to a treating vessel 3 in a desired ratio before they are supplied in the treating vessel 3 is installed, and the etching process of a wafer 4 is performed in an uniformly mixed state.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to semiconductor manufacturing equipment.
In particular, the present invention relates to semiconductor manufacturing equipment that performs processes such as etching and cleaning wafers using chemical solutions.

0002

[Prior Art] Conventionally, this type of semiconductor manufacturing equipment is shown in FIG.
As shown in the cross-sectional view, first, the valve 2 of the chemical liquid supply pipe 1 is opened, the chemical liquid is stored in the processing tank 3, and then the carrier 5 containing the wafers 4 is immersed in the processing tank 3, and the wafers are 4 is subjected to wet processing such as etching and cleaning for a certain period of time. Thereafter, the valve 7 of the pure water supply pipe 6 is opened to continue supplying pure water into the processing tank 3, and the chemical solution in the processing tank 3 is replaced with pure water, thereby removing the wafers 4 in the carrier 5.
Replace the chemical solution adhering to the surface with pure water and clean it. After the wafers 4 have been washed with pure water, a series of processes is performed in which the carrier 5 containing the wafers 4 is taken out of the processing tank 3.

0003

In this conventional processing method using semiconductor manufacturing equipment, a processing tank using a chemical solution and a processing tank using pure water are separated and processing is performed separately. This treatment is performed to reduce the adhesion of particles to the wafer surface, but on the other hand, etching of the wafer surface progresses while the chemical solution is replaced with pure water. While supplying pure water, the concentration of the chemical solution becomes lower as it approaches the pure water supply section, and this state continues until the chemical solution is completely replaced by pure water, resulting in the wafer There is a problem in that the amount of etching is non-uniform within the surface, and this problem is further aggravated by the shapes of the carrier and the processing tank. This non-uniformity in the amount of etching is a major problem in improving yield and reliability as LSIs have become larger in diameter, finer fabricated, and more highly integrated in recent years.

0004

[Means for Solving the Problems] A semiconductor manufacturing apparatus of the present invention includes a processing tank for immersing a carrier containing wafers in a chemical solution and pure water, piping and a valve for supplying pure water, and a tank for supplying pure water. The chemical solution supply piping and valve that supplies the chemical solution into the piping, and the chemical solution/pipe that mixes the chemical solution and pure water.
Equipped with pure water mixing section piping.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a longitudinal sectional view of Embodiment 1 of the present invention. In this embodiment, it is assumed that an oxide film is etched using buffered hydrofluoric acid as a chemical solution and as an initial etching substance, for example. First, inside the treatment tank 4, there is a pure water supply pipe 6.
By opening the valve 7, 1000 to 2000 liters/hour of pure water is supplied. Thereafter, the carrier 5 containing the wafers 4 is immersed in the processing tank 3. Thereafter, the valve 2 of the chemical supply pipe 1 is opened, and after pure water and buffered hydrofluoric acid are uniformly mixed in the chemical/pure water mixing section pipe 8, they are supplied to the processing tank 3, where they are mixed with the wafers 4. oxide film is etched for a certain period of time. After that, the valve 2 of the chemical supply pipe 1 is closed, and only the pure water supplied through the valve 7 of the pure water supply pipe 6 is supplied to the processing tank 4, and the buffered hydrofluoric acid attached to the wafer 4 in the carrier 5 is removed. Replace with pure water and wash. After the cleaning of the wafers 4 with pure water is completed, the carrier 5 containing the wafers 4 is taken out of the processing tank 3.

FIG. 3 is a correlation diagram of actually measured values between the position in the plane of the wafer 4 and the amount of etching when a material to be processed with the wafer 4, for example, an oxide film, is etched using the conventional semiconductor manufacturing equipment and the semiconductor manufacturing equipment of the present invention. It is. In the case of conventional semiconductor manufacturing equipment, the wafer 4 closest to the pure water supply section
While the etching rate at in-plane positions is slow and the etching amount is non-uniform, in the semiconductor manufacturing apparatus of the present invention, the uniformity of the etching amount is significantly improved and the processing accuracy is improved.

FIG. 2 is a longitudinal sectional view of a second embodiment of the present invention. In this example, the in-plane uniformity of the etching amount is further improved than in Example 1 by reducing the flow rate of the chemical solution in stages after the etching process is completed using the mass flow rate adjustment mass flow 9 attached to the chemical supply pipe 1. ing.

[0008]

[Effects of the Invention] As explained above, in the present invention, after a wafer is immersed in a processing tank to which pure water is supplied, a chemical solution is introduced into the pure water supply pipe, and the chemical solution and pure water mixing pipe are After mixing pure water and chemical solution uniformly, the wafer is etched by supplying it into the processing tank. After the processing is completed,
Only pure water is continuously supplied to the processing tank, and the chemical solution adhering to the wafer is replaced with pure water for cleaning.

[0009] Therefore, in conventional semiconductor manufacturing equipment, it is possible to eliminate the etching unevenness caused by the positional unevenness of the chemical concentration that occurs while replacing the chemical liquid with pure water, and to significantly improve the in-plane uniformity of the etching amount. let In addition, the semiconductor manufacturing apparatus of the present invention eliminates particles that are brought into the processing tank together with the chemical liquid when the chemical liquid is introduced in the conventional semiconductor manufacturing apparatus.
It decreases because pure water continues to flow into the processing tank while the wafers are on standby. The above-mentioned effects of uniformity of etching amount, improvement of processing accuracy, and reduction of particles have been achieved by the recent LS
High integration, microfabrication, and large diameter cages have great effects on improving yield and reliability.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of Example 1 of the present invention.

FIG. 2 is a longitudinal sectional view of Example 2 of the present invention.

FIG. 3 is a correlation diagram of actually measured values of the in-plane position of the wafer and the amount of etching in the conventional semiconductor manufacturing apparatus and the semiconductor manufacturing apparatus of the present invention.

FIG. 4 is a longitudinal cross-sectional view of a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

1. Chemical solution supply piping 2 Valve 3. Processing tank 4 Wafer 5. Career 6 Pure water supply piping 7 Valve 8　　　Chemical solution/pure water mixing section piping 9 Mass flow for flow rate adjustment

Claims (1)

[Claims] Claim 1: In a semiconductor manufacturing apparatus that performs wet processing such as cleaning with a chemical solution and etching in the same processing tank, and then cleansing the chemical solution attached to the wafer with pure water,
A semiconductor manufacturing device characterized by having a chemical solution/pure water mixing section piping for mixing a chemical solution and pure water supplied to the processing tank in a desired ratio before supplying the processing tank.