JPS6327025A - Washing method for semiconductor wafer - Google Patents

Abstract

PURPOSE:To wash wafers and jigs uniformly, and to obtain a product having high reliability by washing and treating the wafer and the jig separately. CONSTITUTION:Each wafer 1 is taken out of a carrier 2 at a position P2', and shifted into a washing tank for a wafer washing treating section 4. Only the wafers 1 are washed and treated in the washing tank. An empty carrier 2' from which the wafer 1 is carried out is transported to a washing tank for a carrier washing treating section 5. The carrier 2 is washed by the treating section 5. The washed carrier 2' is transferred, and arranged at a wafer housing position P3'. The washed wafers 1 are aligned and housed in the washed carrier 2' at the position P3'. Accordingly, all the wafer 1 and carrier 2 are washed uniformly, thus acquiring products having high reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaning semiconductor wafers in the manufacturing process of semiconductor devices.

1. In the process of manufacturing a semiconductor device for sitting, it is common to wash the surface of the semiconductor wafer with pure water or the like as a pretreatment for the oxidation or diffusion treatment process of the semiconductor wafer. This cleaning of the semiconductor wafer is intended to equalize the thickness and improve the quality of the film formed on the surface of the semiconductor wafer in the oxidation or diffusion process.

The conventional method for cleaning semiconductor wafers will be explained with reference to FIG. In the figure, (1) is a semiconductor wafer (hereinafter simply referred to as a wafer), (2) is a semiconductor wafer (hereinafter simply referred to as a wafer), and (2) is a semiconductor wafer (1) (1)... that is aligned and held vertically with a fixed pinch, for example, Teflon (registered trademark). [hereinafter referred to as carrier], (3) is a box-shaped transport box that stores a predetermined number of carriers (2), and is used for transporting wafers between each process in the manufacture of semiconductor devices. be done. (4)
is a wafer cleaning processing section, which is not shown in the figure, but the wafer (
1) A cleaning tank containing a cleaning chemical such as pure water for cleaning the surface is provided.

In this conventional method of wafer cleaning, as shown in FIG. A carrier that holds ... in alignment (
2) is taken out and placed at supply position P2. The carrier (2) placed at this supply position P2 is transferred to the wafer cleaning processing section (4) by an appropriate transport mechanism (not shown).
) to the cleaning tank. Then, the carrier (2) is immersed in pure water in this cleaning tank, and the wafers (1) (1)... are removed together with the carrier (2) by shaking the carrier (2) in the pure water, etc. Clean and process. After this wafer cleaning, the carrier (2) in which the cleaned wafers (1), (1), etc. are aligned and held is taken out from the cleaning tank by the transport mechanism and placed at the discharge position P3, and this discharge position P3 The carrier (2) placed in the carry-in position P! From there, it is stored in an express delivery box (3) transferred to a carry-out position P4, and then transferred to the next process such as a drying process.

By the way, in the conventional method of wafer cleaning described above, with a plurality of wafers (1), (1), etc. being aligned and held on the carrier (2), It is washed together with the carrier (2). Therefore, the above wafers (1) (1)... and carrier (2)
Uncleaned areas remained on the wafer (1) (1) near the contact area with the wafer (1) (1), making it difficult to uniformly clean the entire wafer (1) (1). . Furthermore, the contamination of the carrier (2) cannot be ignored, and there is a risk that the wafers (1), (1), etc. may be contaminated by the contamination of the carrier (2).

Furthermore, since the inside of the transport box (3) is only cleaned periodically,
There is a high probability that foreign objects such as dust are present in the transport box (3) that has simply been transferred from the transport box (3) to the transport position P4, and the cleaned wafer (1) stored in the transport box (3) is (1) ... was sometimes contaminated.

The present invention has been proposed in view of the above-mentioned problem, and the technical means for solving this problem is to hold a plurality of semiconductor wafers aligned at a constant pitch in a jig. When cleaning the semiconductor wafer, the semiconductor wafer is taken out from the jig and cleaned, the jig is cleaned in parallel with the semiconductor wafer cleaning, and the semiconductor wafer is stored in the jig. This is a cleaning method for semiconductor wafers.

According to the method of the present invention, each wafer that is aligned and held in a jig is separated from the jig, and each wafer and the jig are individually and separately cleaned, thereby thoroughly cleaning both of them. By uniformly cleaning the wafer and storing the cleaned wafer in a jig that is cleaned separately from the wafer, the wafer is almost never contaminated.

An embodiment of the method for cleaning a semiconductor wafer according to the present invention will be described with reference to FIG. The same or equivalent parts as in FIG. 2 are given the same reference numerals, and their explanation will be omitted. Note that (5) and (6) in FIG.
2) and the transport box (3), a cleaning tank containing a cleaning chemical solution such as pure water is provided.

In the method of the present invention, as shown in FIG.
1) Take out the carrier (2) holding the... in alignment and place it at the supply position P2. Furthermore, the carrier (2) placed at this supply position P2 is transferred to the wafer unloading position P2'', and each wafer (1) (1)... is transferred from the carrier (2) to the wafer loading machine 1 at this position P2''. ] [not shown] and transferred to the cleaning tank of the wafer cleaning processing section (4).In this cleaning tank, the transferred wafers (1) (1)... are aligned in pure water. A wafer storage section (not shown) is provided to hold the wafers, and only the wafers (1), (1), etc. are cleaned.

On the other hand, the empty carrier (2°
) is transferred to the cleaning tank of the carrier cleaning processing section (5), where only the carrier (2') is cleaned in parallel with the above-mentioned wafer cleaning. The cleaned carrier (2'') that has been cleaned and taken out in the carrier cleaning processing section (5) is transferred and placed in the wafer storage position P,'.In this wafer storage position P3', the wafer cleaning process is performed. The wafers (1) (1)... cleaned in section (4) are taken out by a wafer unloading mechanism (not shown) and placed in the cleaned carrier (
2°).

Also, loading position P! The transport box (3) placed in the transport box (3) is transferred to the cleaning tank of the transport box cleaning processing section (6), and the transport box (3) is cleaned in parallel with the wafer and carrier cleaning described above. The cleaned transport box (3) taken out from the transport box cleaning processing section (6)
) is placed at the carry-out position P4, and at this carry-out position P4, the above-mentioned cleaned wafers (1), (1), and
The carrier (2) in which the ... are aligned and held is stored in the transport box (3) and transported to the next process.

According to the method of the present invention, by cleaning the wafer and the jig individually and separately, it is possible to uniformly clean the wafer and the jig to every corner. There is no possibility that the carrier will be recontaminated with dirty carriers, resulting in a significant improvement in yield and the provision of highly reliable products.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining an embodiment of the semiconductor wafer cleaning method according to the present invention, and FIG. 2 is a schematic diagram for explaining a conventional semiconductor wafer cleaning method. (1') -・Semiconductor wafer [wafer], (2)
(2”) - Jig [carrier]. Patent applicant: Kaisai NEC Co., Ltd.
Rinto Gangwon Province Go 1st r.
A, f Meikata J Murimaro, P4 in Figure 2

Claims (1)

[Claims] (1) When cleaning a plurality of semiconductor wafers that are aligned and held at a fixed pitch in a jig, the semiconductor wafers are taken out from the jig and cleaned, and the jig is used in parallel with cleaning the semiconductor wafers. 1. A method for cleaning a semiconductor wafer, comprising: cleaning the semiconductor wafer; and storing the semiconductor wafer in the jig.