JPS60200530A - Method for terminating etching of semiconductor wafer - Google Patents

Abstract

PURPOSE:To process a quantity of large-diameter wafers simultaneously by a method wherein an etching tub is quickly submerged in a water tub upon completion of etching. CONSTITUTION:An etchant 4 is placed in an etching tub 11 capable of processing a great number of wafers. An ordinary wafer holder 6 containing wafers 5 is placed in the etching tub 11. The tub 11 is then caused to float on pure water in a water tub 7. The wafer holder 6 is coupled to an automatic rocking unit 8 for vertical movement. When the removal is completed as prescribed from the wafer surface, an arm 9 belonging to the automatic rocking unit 8 is extended. As the result, the wafer holder 6 applies pressure to the bottom of the etching tub 11 to cause a stopper 10 to be released. The etching tub 11 and wafer holder 6 carrying the wafers go down into the water tub 7. With the unit being designed as such, etching can be brought to a stop very quickly, which contributes to the realization of an etching process wherein large-diameter wafers are etched in great quantities.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for rapidly stopping an etching reaction at the end of etching a semiconductor wafer (hereinafter referred to as a wafer), particularly a silicon wafer.

Conventionally, when finishing the etching of the wafer and stopping the etching reaction, as shown in Fig. 1, approximately 2 L of an etching solution of, for example, +f, HNO3-HF system, was put into the 1' etching bath 1, and the wafer was etched. The holder 2 loaded with about 20 wafers is placed in the etching tank 1, and the holder 2 is manually rocked up and down to advance the etching reaction. After a predetermined time has elapsed, a predetermined removal amount on the wafer surface is obtained. In order to stop the etching reaction, the etching tank 1 was held in both hands, and water was rapidly poured into the tank 1 from above to stop the reaction.

However, in this method of stopping the reaction, water is manually injected from the soil in the etching tank 1 all at once, so there is a fK limit for the water that can be injected, and in order to stop the reaction stably, it is necessary to The maximum number of wafers that can be etched at one time is limited to 20 wafers, and the diameter is limited to 3" or less. When etching a large number of wafers, it is necessary to perform etching many times, so it is necessary to prepare the etching solution and stop the reaction. It is necessary to repeat the steps repeatedly, which reduces work efficiency and increases fatigue.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, to perform etching on large diameter wafers at one time, and to rapidly and reliably stop the etching reaction.

The gist of the present invention is to rapidly stop the etching reaction by rapidly sinking the etching tank into the water tank after etching has been completed.

Hereinafter, the present invention will be described in detail according to an embodiment shown in the drawings.

FIGS. 2, 3, and 4 are diagrams showing an embodiment of rapid termination of an etching reaction according to the present invention. FIG. 2 is a perspective view showing the etching tank 11 placed in the water tank 7, and FIG. 3 is a cross section taken along the line A-A in FIG. FIG. 3 shows the enching reaction in progress.

FIG. 4 also shows the reaction stopped state.

For example, an NHO3 + HF-based etching solution 4 is placed in an etching tank 11, and a normal wafer holder 6 filled with a wafer 5 is immersed in the water tank 7 filled with pure water.
Floating on. The etching tank 11 has a semi-cylindrical shape, holds about 15 wafers of etching liquid, can have a diameter of 5 or 6 wafers, and can etch about 100 wafers at a time. Next, the wafer holder 6 loaded with the wafer is connected to an automatic movement device 8 (mechanism not shown) and automatically moves up and down to advance the etching reaction. After a predetermined machining allowance for the wafer surface is obtained, the arm 9 attached to the automatic movement device 8 is extended. To extend the arm 9, for example, the arm 9 is a combination of a thin rod and a pipe, and a hook is provided in the middle, and when the etching is finished, the hook is automatically removed and the thin rod is removed using a timer set to the etching time. The arm 9 can be extended by extending it from inside the via. As a result, the wafer holder 6
pushes the bottom of the etching tank 11, the stopper 10 is released, and the etching tank 11 and the wafer holder 6 loaded with wafers sink into the water tank 7.

FIG. 4 shows the state in which it has sunk in this manner.

In this way, the etching reaction can be rapidly stopped.

In this embodiment, the etching reaction can be rapidly stopped by removing the stopper 10 by extending the arm 9, or by removing the stopper 10 manually or automatically using a timer set at the end of a predetermined etching time.

Further, the arm 9 is fixed to the wafer holder 6 and the self-moving machine 8, and after etching is completed, the stopper is removed manually or automatically by a timer, and the etching process is completed (only the wafer holder 6 and the wafer holder 6 and the wafer holder 6 and the wafer wafer 11 are lowered into the water tank 7). S
It is also possible to rapidly stop the etching reaction by leaving position 5 as it is.

A stopper 13 is installed on the opposite side of the stopper 10 from the etching tank 11 to provide balance.

As a result of various experiments using each of the methods described above, it has become possible to etch about 100 sheets of 5 or 60 diameter wafers at a time, and to stop the etching quickly. It has become possible to perform wafer etching work, and it has also become possible to stably obtain a good wafer surface.

When performing lock and large-volume etching work, the work efficiency has been greatly improved, making it safer and reducing work fatigue.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a conventional etching reaction termination device. FIG. 2 is a partial perspective view of an embodiment according to the present invention. FIG. 3 and FIG. 4 are partial cross-sectional views of one embodiment of the present invention. 4... Etching liquid, 5...
...Wafer, 6...Wafer holder, 7.
...Aquarium 8...Automatic rocker, 9...
・・Arm, 10・・・・Strong bar-111・・・・
・Etching type, 12...Rotating support rod patent applicant Komatsu Denshi Kinkyu Co., Ltd. Figure 7 Figure 2

Claims (1)

[Claims] 1. A method for terminating the etching reaction of a semiconductor wafer and stopping the etching reaction, characterized in that the etching reaction is rapidly stopped by rapidly lowering the etching tank into a water tank. A method for stopping the etching reaction. 2. Remove the stopper 10 by extending the arm 9,
Etching 4111 and wafer holder 6 in water tank 7
2. The method of terminating an etching reaction according to claim 1, wherein the etching reaction is rapidly submerged in the etching process. 3. The stopper 10 is removed by automatically extending the arm 9 using a timer, and the etching bath 11 and the wafer holder 6 are rapidly lowered into the water 41#7. Etching stop device.