JPH0746347Y2 - Chemical processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chemical treatment apparatus, and more specifically, it facilitates the control of minute amounts of chemicals in a chemical treatment tank for wafers such as cleaning, etching and resist removal in a wafer process of a semiconductor manufacturing process. The present invention relates to a chemical processing device.

During the semiconductor device manufacturing process, in a semiconductor wafer process using silicon, foreign substances such as dust adhering to the wafer surface are cleaned with acid, alkali, organic solvent, etc. or the insulating layer or silicon film is etched with acid. In order to remove the resist film used during the etching, an apparatus as shown in FIG. 1 is used. For example, an appropriate amount of trichlene 1a for wafer cleaning is placed in the chemical supply tank 1 and the trichlene 5a is also placed in the processing tank 5. Next, 25 4-inch silicon wafers are immersed in the trichlene 5a. The wafer is supported by a carrier. When the wafer is immersed in the trichlene 5a for a certain time and the cleaning is completed, the next 25 wafers are similarly immersed in the trichlene 5a to perform the cleaning. As the wafer is continuously cleaned in this way, the trichlene 5a in the processing tank 5 is consumed due to adhesion to the surface of the cleaned wafer, evaporation and the like. In order to make up for this consumed amount, the air valve 3 arranged between the chemical supply tank 1 and the processing tank 5 is manually opened, and the chemical in the chemical supply tank 1 is transferred to the processing tank 5 via the supply pipe. Is supplied in. However, with this conventional apparatus, it was difficult to finely adjust the amount of chemicals in the processing tank for the consumed processing liquid.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to improve the above-mentioned problems, and to provide a chemical treatment apparatus capable of easily supplying an initial supply of a large amount of processing liquid and thereafter supplying a very small amount of processing liquid.

The object of the present invention is to provide a main tank for supplying a chemical solution, a chemical supply tank for storing a certain amount of the chemical solution supplied from the main tank, and a wafer processing tank for storing the chemical solution supplied from the chemical supply tank and processing a wafer. And a pipe for supplying a chemical to the processing tank is provided between the chemical supply tank and the wafer processing tank in two systems, a large flow rate and a small flow rate, against the consumption of the chemical in the processing tank. And a minute amount of the chemical is supplied from the tank to the processing tank to maintain a constant amount of the chemical in the processing tank.

Hereinafter, the present invention will be described in detail based on embodiments.

2 and 3 are schematic explanatory views showing an embodiment according to the present invention.

According to FIG. 2, the chemical supply tank 1 always stores a necessary amount of chemicals such as trichlene 1a in the treatment tank 5, and when the treatment tank 5 is empty, the air valve 3 on the large flow rate system side is opened. After the trichlene 1a in the chemical supply tank 1 is completely supplied to the processing tank 5 through the pipes 2a and 4, the air valve is closed. Thereafter, the required amount of trichlene is again stored in the tank 1 from the main tank 8 via the supply pipe 9. After that, by a so-called semiconductor wafer process, the liquid level of trichlene 5a in the processing tank 5 is lowered due to consumption such as adhesion of trichlene (processing liquid) 5a to the surface of the naturally evaporated wafer. The air valve 6 of this small flow rate system is periodically opened, for example, every 6 minutes for one set of 25 semiconductor wafers of 4 inches for a fixed time, for example, 10 seconds to open the trichlene in the processing tank 5.
The amount of 5a is supplemented via the pipe 2b. By adjusting the flow rate by the needle valve 7 and setting the interval between the needle valve 7 and the air valve 6 to be opened and the time for which the air valve 6 is opened to an optimum state, the liquid level in the processing tank 7 can be always kept constant.

FIG. 3 shows another embodiment of the present invention and is almost the same as FIG. 2, except that the needle valve 7a of the minute amount supply pipe has a motor 7b. The needle valve 7a is of a motor drive type, the liquid level sensor 11 is provided on the liquid surface of the trichlene 5a in the processing tank 5, and the controller 10 for inputting the sensor signal and providing the drive signal to the motor is It is a point that is equipped. In this embodiment, the trichlene 5a is automatically supplied according to the change in the liquid level. Also in this case, the air valve 3 on the large flow rate supply side
The initial supply is performed by opening the pipe 2a, while the air valve 6 and the needle valve 7a on the small flow rate supply side are provided.
A minute amount is supplied through the pipe 2b by appropriate adjustment of. Particularly, in this embodiment, the liquid level sensor 11 and the controller 10 for inputting the sensor signal and supplying the drive signal to the motor are provided so that the flow rate on the small flow rate supply side is changed and supplied according to the change of the liquid level. Therefore, it is particularly effective when the fluctuation of the liquid surface is aperiodic, or when the amount of consumption of the liquid is large and it is necessary to constantly supply a certain amount of chemical.

Although the chemical used in the examples is trichlene, it goes without saying that various chemicals can be used depending on the purpose of the semiconductor process. By setting the flow rate by the needle valve 7 and the interval and time for opening the air valve 6 according to the type of chemical, temperature, frequency of use, volume of processing tank, any chemical,
It can also be applied to processing tanks.

As described above, the present invention fills the processing tank with the chemicals in a short time in the initial state by providing the large flow rate and the small flow rate piping for supplying the chemicals to the processing vessel, and supplies the minute amount of the chemicals during the processing. It is possible to improve the work efficiency because it can be performed easily.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a conventional embodiment, and FIGS. 2 and 3 are explanatory views showing an embodiment of the present invention. 1 ... chemical supply tank, 1a ... trichlene, 2, 2a, 2b ... piping, 3 '... air valve, 3 ... large flow rate supply side air valve, 4 ... piping, 5 ... treatment tank, 5a ... trichlene, 6 ... small flow rate Supply side air valve, 7, 7a ... Needle valve, 7b ... Motor, 8 ... Main tank, 9 ... Piping, 10 ... Controller.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mikio Fujii 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Hideki Miyaji, 1015, Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (1)

[Scope of utility model registration request] 1. A main tank for supplying a chemical solution, a chemical supply tank for storing a fixed amount of the chemical solution supplied from the main tank, and a wafer processing tank for storing the chemical solution supplied from the chemical supply tank and processing a wafer. By disposing two pipes for supplying chemicals to the processing tank between the chemical supply tank and the wafer processing tank, one having a large flow rate and the other having a small flow rate. A chemical treatment apparatus, characterized in that a very small amount of chemical is supplied from the tank to the treatment tank to maintain a constant amount of the chemical in the treatment tank.