JPS5892225A - Wafer washing device - Google Patents

Abstract

PURPOSE:To increase washing effect and to reduce a floor area by a method wherein a vertical washing processing tank which successively moves wafers inserted from the upper part into a low-layer processing tank under its own weight is provided. CONSTITUTION:A washing processing tank 1 is vertically positioned and a basket 8, a belt conveyor 9, and a handling mechanism 10 are positioned at the upper part of the tank 1. A handling mechanism 10a, an air track 12, and a basket 13 are positioned at the lower part of the tank 1. To move a wafer 20 completed washing in an upper-layer processing tank 2a into a low-layer processing tank 2b, a washing solution in the upper-layer processing tank 2a is previously drawn out under the condition that the valve rod 26 of a gate valve is open, and the low-layer processing tank 2b is simultaneously filled with a washing solution. Then, when the valve rod 26 is open, the wafer 20 passes through a through hole 25 by tare weight and slowly moves to the low-layer processing tank 26.

Description

DETAILED DESCRIPTION OF THE INVENTION <1) Technical Field of the Invention The present invention relates to a silicon wafer cleaning apparatus, and more particularly to an in-line vertical cleaning apparatus.

(2) Background of the Technology As the steps in manufacturing semiconductor devices become more complex and the number of steps increases, automation of the manufacturing process is becoming increasingly important. The purpose of such automation is to improve quality, improve yield, and reduce production costs, but cleaning of semiconductor wafers is one of the most important factors that determines the performance and reliability of semiconductor devices. Therefore, great care and attention is required when automating wafer cleaning.

What must be considered in the above-mentioned automation is whether to process one wafer or to punch a wafer. In general, batch processing seems to be more advantageous in terms of mass production, but this problem should be selected in relation to the processes before and after wafer cleaning. In other words, care must be taken to ensure that the wafer is processed without stagnation, and in this respect, the recent trend toward single-wafer processing in manufacturing processes, such as resist processing using a spin code method, plasma etching, or chemical vapor deposition method, is important. Looking at the trend toward single-wafer processing in (CVD), vapor deposition, etc., we can see that even in cleaning processing, in-line methods
It is desired to realize a cleaning device that can process sheets one by one.

(3) Conventional technology and problems Conventionally, wafer cleaning has mainly been carried out by batch processing, in which approximately 25 wafers are usually placed in one basketball throat.
Cleaning is performed by sequentially moving through each processing tank arranged horizontally.

By the way, various contaminants such as organic substances, heavy metals, and ionic contaminants are attached to the wafer surface, and many processing tanks are provided for cleaning and removing these contaminants. Therefore, the floor area occupied by the cleaning equipment inevitably becomes large, and since the process is a batch process, there is a problem in that it is difficult to perform the cleaning process following the single-sheet processing operations in other processes mentioned above. .

(4) Purpose of the Invention The present invention has been made in view of the above-mentioned drawbacks of the prior art, and its primary purpose is to provide a wafer cleaning apparatus that can process one wafer using an in-line method, has a large cleaning effect, and has excellent production efficiency. .

(5) Structure of the Invention The present invention consists of a plurality of processing tanks stacked vertically and a gate valve forming a joint between the processing tanks, and each processing tank can be opened and closed independently by opening and closing the gate valve. A vertical cleaning tank is provided which is functional and allows wafers inserted from above to be moved sequentially by their own weight to lower processing tanks, a spin dryer is provided below the cleaning tank, and a spin dryer is installed below the cleaning tank. A wafer cleaning device is provided, characterized in that wafer conveyance and handling mechanisms are provided at upper and lower positions.

(6) Embodiments of the invention Hereinafter, embodiments of the invention will be described based on the accompanying drawings.

FIG. 1 shows an operating system of a wafer cleaning apparatus according to the present invention, partially in sectional view and partially in perspective view. In the figure, reference numeral 1 denotes a cleaning treatment tank, and a treatment tank 2°- and a cleaning tank 2. - gate valves interconnecting 3. - are arranged in the vertical direction, and a wafer insertion opening 4 is provided at the upper end, and each processing tank 2 is arranged vertically.
．． There is a water inlet at the bottom of one side of 5.・-, and drain port 6. above the opposite side. -・- (represented by a dashed-dotted line) is provided. Note 7. - represents the valve stem. Here, processing tank 2. -. As shown in the cross-sectional view of FIG. 2, rails 22. -, and the wafer 20 moves along the rails 22°- while maintaining a substantially vertical state.

Also, gate valve 3. - As shown in the vertical cross-sectional view of FIG. A processing tank 2a is provided on the upper and lower end surfaces of the body 24.
, 2b is Pol)27. - Fixed by. With this configuration, for example, when trying to transfer the wafer 20 that has been cleaned in the upper processing tank 2a to the lower processing tank 2b,
With the valve stem 26 of the gate valve open, the cleaning liquid from the upper processing tank 2a is drawn out in advance, and at the same time, the cleaning liquid from the lower processing tank 2b is filled, and then when the valve stem 26 is opened, the wafer 20 is moved by its own weight. As a result, it passes through the through hole 25 and slowly moves to the lower processing tank 2b. Then valve stem 2 again
6 is closed, and cleaning in the next lower layer processing tank 2a is started. In this way, the wafers that have been cleaned can be sequentially transferred to the lower processing tank, and new cleaning can be performed one after another.

The cleaning treatment tank 1 configured as described above is arranged vertically,
As shown in FIG. 1, a basket 8, a belt conveyor 9, and a handling mechanism 10 are arranged above it, and a handling mechanism 10a1, an air track 12, and a basket 13 are arranged below it. Spin dry wA11 is
For example, one pair of upper rollers lla and one pair of lower rollers ll
The upper rollers lla can each move in the horizontal direction, and the lower rollers llb move upward to pick up the processed wafer 20, and then descend to chuck it with four rollers. It then rotates and has the function of mechanically blowing away the water that has adhered to it.

With this mechanism, the belt conveyor 9 is transferred from the basket 8 to the belt conveyor 9.
The transferred wafer 20 is transported above the cleaning tank 1 and inserted into the insertion port 4 by the handling mechanism 10. The wafer 20, which has completed the specified cleaning while passing through the cleaning treatment tank l, is dried by the spin dryer 11, and then transferred to the air track 1 by the handling mechanism 10a.
2, and after being conveyed in a non-contact manner on the air trunk I2, it overlaps the basket 13. This flow of wafers 20 is shown by white arrows in FIG.
It is processed one by one and all automatically.

Therefore, each processing tank 2 constituting the cleaning processing tank 1, ---
The number of processing tanks and cleaning steps can be changed arbitrarily depending on the degree of contamination of the target wafer, but in this example, as shown in FIG. I did this. Here, the cleaning liquid in each treatment tank is as follows.

Processing tank Cleaning liquid 1 820 U NHIlOH+ H2O2+ 820 (
heating) m I (20 IV I20 V H (J!+H2O2+H20 (warming) VI
I20 ■ I20 In addition, (NHlloH+ H2O1
+H20) liquid was used by recirculation.

As a result of processing under the above conditions, a great cleaning effect could be obtained.

(7) Effects of the Invention As explained in detail above, the present invention is capable of processing a single wafer by organically combining a cleaning treatment tank, a spin dryer, and other peripheral devices, such as a transfer device and a handling mechanism. In particular, the cleaning treatment tank has a structure in which multiple treatment tanks with independent cleaning functions can be arranged vertically, increasing the degree of freedom in the cleaning process. The cleaning effect is great, and the floor space can be reduced, which has great effects. In addition, processing liquids can be disposed of or recycled depending on their type, allowing rational use of various processing liquids.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a wafer cleaning processing apparatus according to the present invention, Fig. 2 is a cross-sectional view showing the structure of a processing tank, Fig. 3 is a longitudinal sectional view showing the structure of a gate valve, and Fig. 4 is a cleaning It is a block diagram for explaining the cleaning process in a processing tank. 1--Cleaning treatment tank, 2.2a, 2b--Processing tank, 3.
- Gate valve, 4 - Insertion port, 5... Water supply port, 6
- Drain port, 7.26 - Valve stem, 8... Basket,
9.-Belt conveyor, 10.10a... Handling mechanism, 11- Spin dryer, lla, l1b-Roller, 12-4 Atlas Tsuk, 13... Basket, 2
0... Ueno%, 2l-18 bodies, 22- rail, 2
3--valve seat, 24--valve body, 25--through hole, 2
7-...Bolt 22 22 Figure 2 Figure 3 Figure 4 (Nl

Claims (1)

[Claims] A cleaning tank consisting of a plurality of processing tanks stacked vertically and a gate valve that can be opened and closed is provided to form a joint between the processing tanks, and spin drying is provided below the cleaning tank. 1. A wafer cleaning device capable of processing one wafer at a time, characterized in that a wafer cleaning device is provided above and below the cleaning processing tank, and a transfer device and a handling mechanism are provided above and below the cleaning processing tank.