JPS5824938B2 - Etching Souch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an etching apparatus that can uniformly and efficiently process semiconductor elements.

When etching silicon wafers, air bubbles generated by chemical reactions remain on the wafer surface, which is a factor that impedes the uniformity of the etching process. Therefore, the air bubbles formed on the wafer surface must be quickly removed.

The present invention instantly eliminates the air bubbles generated during the etching process as described above, always brings fresh etching solution into contact with the wafer surface, and performs highly uniform etching. It is an object of the present invention to provide an etching device with high workability and reliability, which reduces the chance of contact of an etching liquid with an operator.

The present invention will be described in detail below with reference to the drawings.

FIGS. 1A and 1B are structural cross-sectional views showing one embodiment of the etching apparatus of the present invention, which includes a processing tank 1 for performing etching processing, a liquid storage tank 2 for storing surplus liquid, and a supply for supplying etching liquid. It has a three-tank structure including a liquid tank 3. The processing tank 1 and the supply liquid tank 3 are connected by a connecting pipe 4, and a spray nozzle 5 is provided at the tip of the connecting pipe 4.

In addition, liquid level control pipes 6 and 6' are provided between the processing tank 1 and the liquid storage tank 2, and the excess liquid in the processing tank 1 is drained to the liquid storage tank 2 through the drain hole 7, and the liquid level in the processing tank 1 is as follows. It can be held at any position by sliding the liquid level control tube 6' up and down.

A movable stopper 8 is provided between the liquid reservoir tank 2 and the supply liquid tank 3, and the movable stopper 8 is opened and closed by 10 pressures of gas (or pressurized air) ejected from the opening of a pressurizing pipe 9 provided directly below. It has a structure that allows

The closed state of the movable stopper 8 is shown in FIG. 1B.

The etching process using the apparatus of this embodiment is shown in Figure 2.
Shown below.

In addition, the dotted line arrow in the same figure shows a pressurized gas flow, and the solid line arrow shows a liquid flow.

First, an etching solution is poured into the processing tank 1, and a specified amount of the etching solution is supplied to the processing tank 1 and the supply liquid tank 3.

At this time, the movable stopper 8 of the liquid storage tank 2 is open, and the processing tank 1
Excess liquid out of the liquid injected into the tank is drained from the liquid drain hole 7 to the liquid storage tank 2.
However, it does not remain in the liquid storage tank 2, but is all injected into the supply liquid tank 3 (I in the same figure).

The liquid level in the processing tank 1 at the end of the supply maintains the surface of the injection nozzle 5, as shown in FIG. 2I.

After injecting and supplying the etching liquid as described above, a pressurized gas 10, such as N2 gas or pressurized air, is supplied from the pressurizing pipe 9 to 0.5 to 3 Ky/CTL (depending on the dimensions of the device, the amount of liquid, and the amount of liquid used). When the movable stopper 8 is closed by the injection gas pressure, the pressure in the supply liquid tank 3 increases, and the liquid in the supply liquid tank 3 increases. is injected into the processing tank 1 from the injection nozzle 5 via the connecting pipe 4.

After the inside of the processing tank 1 is brought into a state of jet liquid as described above, the sample 12 held in the sample holder 11 is inserted into the processing tank 1, and an etching process is performed.

At this time, the sample 12 is placed in front of the injection nozzle 5 at a position ranging from perpendicular to parallel to the flow of the jet liquid (the opposing angle between the flow of the jet liquid and the sample surface differs depending on the sample conditions). is constantly exposed to a rapid jet of liquid, and air bubbles generated from the sample surface are instantly removed without being trapped, and the sample surface is etched with fresh liquid constantly supplied, resulting in a uniform etching process. .

Furthermore, since the process is carried out in a jet liquid, the fine parts of the fine pattern are reliably etched, and since there is no contact between the sample and the gas, no unnecessary reactions occur on the sample (■ in the same figure).
.

In addition, since the excess liquid in the processing tank 1 supplied from the supply liquid tank 3 is removed to the liquid storage tank 2 through the liquid drain hole 7 of the liquid level control pipe 6', the influence of liquid volume fluctuations on the etching conditions is reduced. (■ in the same figure).

After the etching process is completed, the sample is taken out from the processing tank 1, the pressurized gas 10 is stopped, and the supply of liquid from the supply tank 3 to the processing tank 1 is stopped, and the movable stopper 8 is opened, and the liquid storage tank 2 The liquid inside is collected in the supply liquid tank 3 (Fig. 2, ■).

Thereafter, uniform etching can be performed by simply supplying and stopping the pressurized gas 10, inserting and removing the sample 12, and etching can be performed with almost no chance for the operator to come into contact with the dangerous etching solution.

In this actual case, the circulation mechanism includes a liquid level control pipe, a connecting pipe, a movable stopper, a pressurized gas pipe, etc.

In the above description, the injection nozzle 5 is provided at one location, but by providing a plurality of injection nozzles 5, a large amount of etching can be performed at the same time.

It is also possible to simply configure the circulation mechanism with a pressurized gas pipe and a circulation pipe.

As explained above, the etching apparatus of the present invention, which is equipped with a circulation mechanism that circulates excess liquid in the etching liquid in the processing tank and that circulates surplus liquid to the jet nozzle, is capable of handling a rapid jet flow in the etching liquid. Because it performs an etching process, it is particularly effective for removing bubbles from electrolytic etching, aluminum etching, etc., which generate many bubbles, and because there is no contact between the sample and gas, no unnecessary reactions occur in the sample, and it has no practical value. It's expensive.

[Brief explanation of the drawing]

FIGS. 1A and 1B are structural sectional views showing an embodiment of the etching apparatus of the present invention, and FIGS. 2I to 2 are operational functional diagrams during etching processing by the apparatus of this embodiment. DESCRIPTION OF SYMBOLS 1...Touching treatment tank, 2...Excess liquid storage tank, 3...Supply liquid tank, 4...Connecting pipe, 5... ...Injection nozzle, 6,6'...
・Liquid level control pipe, 7... Drain hole, 8... Movable stopper, 9... Pressurized gas pipe, 10... Pressurized gas, 11... ...Sample holder, 12...
··sample.

Claims (1)

[Claims] 1. The etching treatment tank and the supply liquid tank are connected by a connecting pipe that connects to an injection nozzle provided in the etching liquid in the etching treatment tank, and the etching treatment tank and the liquid storage tank are connected to the supply liquid tank in the etching treatment tank. The liquid storage tank and the supply liquid tank are connected by a liquid level control pipe, and the opening connecting the liquid storage tank and the supply liquid tank is opened and closed by a movable stopper provided in the liquid distribution tank using the gas pressure of a pressurized gas pipe in the supply liquid tank. An etching apparatus characterized in that the etching liquid in the supply liquid tank is jetted from the jet nozzle by the gas pressure.