JPS60246639A - Wet processing method for wafer - Google Patents

Abstract

PURPOSE:To enhance washing effect while reducing the volume of necessary washing liquid by a method wherein a plurality of wafers is arranged to radiate from the center of a cylindrical holder and the wafer surfaces are slightly dislocated to face though not fully the center of the holder so that they may be exposed to a washing liquid effused from the central position in the holder. CONSTITUTION:A nozzle section 15 for the effusion of a washing liquid is arranged on the central axle 13 of a holder 12 accommodating wafers 11. The nozzle section 15 should be separate from the central axle 13. The nozzle section 15 may be suspended from above or installed slidably on the central axle 13. A washing liquid, pure water for example, is effused under high pressure out of a plurality of nozzles, to strike the wafers 11. The water then flows down on the surfaces of the wafers 11, cleaning the surfaces. Effusion of a sufficiently large volume of water results in a situation wherein the water reaches the rear surfaces of the wafers 11 for further cleaning. A washing method wherein the wafer surfaces are constantly in contact with fresh, pure water is more effective than a conventional method wherein wafers are submerged in a washing liquid. In addition, the flow-down method requires less liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION fal Technical Field of the Invention The present invention relates to a method for wet processing of wafers, and more particularly to a novel cleaning method for performing cleaning with pure water.

(t+1) Background of the Technology As is well known, semiconductor devices such as ICs are formed on semiconductor wafers, and are made into semiconductor elements (chips) through a wafer process.

In such a wafer process, F6 liquid treatment (wet treatment) is repeatedly performed, and the solution treatment is accompanied by cleaning with pure water, for example, etching treatment for opening windows. Cleaning with pure water is always performed afterwards. Also, before the heat treatment process, etching cleaning with chemicals and pure water cleaning are performed, and the cleaning before this process is called pretreatment, but pretreatment is not heat treatment and is also performed in other processes. As described above, the wafer process is a process that requires a large amount of cleaning.

On the other hand, semiconductor devices such as ICs have made amazing progress, and wafer processes have become significantly more mass-produced and automated, but semiconductor wafers (hereinafter referred to as wafers) have also become extremely large in diameter. The diameter of the wafer is expected to increase from the current 3 to 5 inches to 6 to 8 inches in the near future.

(C1 Prior Art and Problems) The conventional cleaning processing method for such wafers is to store a large number of wafers in a wafer holder, and to use the wafer holder in a processing container filled with a cleaning solution (for example, pure water). A sectional view of this treatment method is shown in Figure 1.
The wafer holter 93 is a processing container filled with a solution.
The cleaning liquid is constantly flowing in and out of the processing container 3, and the wafer holder is immersed in the processing container, and the handle 21 of the wafer holder is pushed and shaken downward, or the handle 21 is 1-1 with an automatic machine. Clean by applying downward motion.

1m], and in the upper notinku treatment, the enotinku solution is placed in the same treatment container and the same treatment method is carried out.

However, when such a processing method is carried out, there is a problem that as the diameter of the wafer becomes larger, the processing container 3 becomes larger, the amount of cleaning liquid used increases, and the cost per stroke of wafer processing increases. In addition to pure water, chemicals such as dilute hydrofluoric acid and alcohol are used as the cleaning liquid.

Further, in this method of cleaning by immersing the wafer in a container, it is desirable that the cleaning liquid is quickly replaced so that the wafer comes into contact with fresh cleaning liquid. However, when the diameter of the wafer becomes larger and the processing container 3 becomes larger, the above method has the problem that it takes a long time to circulate the cleaning liquid and that the cleaning result becomes low F. This is a major problem in Obu City, and has an extremely negative impact on the quality of wafers.

fd+ OBJECT OF THE INVENTION The present invention proposes a cleaning method that solves the above-mentioned problems, that is, a cleaning method that reduces the amount of solution used and improves the cleaning effect.

tel Structure of the Invention The purpose of the invention is to arrange a plurality of wafers in a cylindrical wafer holder radially from the center of the wafer holder, with the wafer surface slightly oriented toward the center, This is achieved by a wet wafer processing method in which a processing liquid is sprayed onto the wafer surface from a wafer.

(“) Examples of the invention Examples will be described in detail below with reference to nine drawings.

FIG. 2 is a perspective view 7 of a P2 Ever Holter which is used in the wet processing method according to the present invention, and FIG. 3 1 is a plan view thereof. As shown, a large number of wafers 1
The wafer 1 is placed in the holder 12 radially from the central axis 13 of the boulder, with the wafer surface facing slightly toward the center, and the surrounding wall and bottom of the holder are exposed to the solution. Porous (= 8 pores) so you can go in and out freely.
It is attached to a wall. In addition, in order to hold the wafer 11 in the wafer handle 12, three claws 4 are provided for each wafer in the holder, and the claws 14 are shown in FIG. ing.

FIG. 4 is a cross-sectional view of the curve ΔΔ in FIG. 3.

Here, the wafer holder 12 shown in FIGS. 2 to 4 is one embodiment, and the structure shown in FIG. For example, instead of using the claws 14 for holding the wafer, there is a method in which the inner wall around the holter and around the central axis are formed into an uneven shape, and the wafer is held by fitting into the recess. Alternatively, the wall surface of the wafer holder may have a net-like structure.

Next, a typical example of a cleaning treatment method using the above-mentioned wafer boulder will be explained with reference to FIG.

Figure 5 ta+ is a side sectional view of the wafer holter, Figure 5-1
(11) is a plan view taken at 813 in FIG. is separate from the central axis 13, I:'
The nozzle 8jt is suspended from -8rX, or the nozzle part and the central axis are slid together.

When a cleaning liquid such as pure water is applied at high pressure from multiple nozzles, the pure water hits a part of the wafer 11, and the hit pure water flows down the wafer 7 and cleans the wafer. The surface is cleaned. In addition, if the amount of sprayed water is large enough, the deionized water will penetrate to the back side of the wafer, cleaning both sides of the wafer. In this cleaning method, the wafer surface is constantly in contact with fresh deionized water. Therefore, the cleaning effect is greater than that of the immersion method.Furthermore, this flow-down method has the effect of requiring less liquid.

History ζ This processing method is the first Fl! -L of the stage 16 that slides the wafer holder 12 without leaving the 1tal.
When placed in the wafer holder, the pure water injection pressure
- Can rotate itself. Then -IN
Uniform cleaning can be performed.

Furthermore, when using a wafer boulder that is compatible with the present invention,
In contrast to the above-mentioned cleaning method, cleaning can also be carried out by spraying a cleaning liquid over the entire surface of the wafer holter 12 from the F side, and the cleaning effect is similarly great. (1) In the above cleaning processing method, when drying gas is injected from the 7' nozzle part 15, the drying time after cleaning becomes l1Jti. The etching solution can be stirred by bubbling.

Therefore, the cleaning processing method according to the present invention can be incorporated into the entire solution processing system and adapted to automated processing, and in that case, there is a meli-node that allows the processing area to be compact despite the wafer being made into a doll.

(g) Effects of the Invention As is clear from the above explanation, the wafer processing according to the present invention can reduce the amount of processing solution used and improve the cleaning efficiency, which can be useful for improving the quality of wafers.

This feature greatly contributes to reducing the downtime and improving the quality of semiconductor devices such as ICs.

[Brief explanation of drawings]

Figure 1 is a diagram showing the conventional solution processing method for wafers;
The figure is a perspective view of a wafer holder that is applicable to the solution processing method according to the present invention, FIG. 3 is a plan view thereof, FIG. 4 is an AA lli side view of FIG. FIG. 5 is a cross-sectional view of an example of a wafer holder for explaining the method (BL is a plan view taken along HB of fat in the figure. In the figure, 1.1.1 is a wafer, and 2 is a conventional wafer holder. 13 is a processing container, +2 is a wafer holder according to the present invention, 13 is a central axis, 14 is a claw, 15 is a nozzle part,
16 indicates a stage. Figure 1 Figure 2 Figure 3 Figure 4 Figure 50

Claims (1)

[Claims] A plurality of wafers are arranged in a cylindrical wafer holder radially from the center of the wafer holder, with the wafer surface slightly oriented toward the center, and a processing liquid is sprayed onto the wafer surface from the center of the wafer holder. A wafer wet processing method characterized in that: