JPH03255629A - Cleaning process for semiconductor wafer - Google Patents

Abstract

PURPOSE:To avoid the adherence of any dust, stain, etc., to wafer rear surfaces, etc., during the wafer carriage step by a method wherein both surfaces of wafers contained in a carrier are simultaneously and efficiently cleaned up by mixing a cleaning solution with resin-made cleaning pieces. CONSTITUTION:Within a cleaning vessel 3 composed of an inner vessel 3a and an outer vessel 3b, the inner vessel 3a is overflowed by feeding a cleaning solution 12 comprising acid, alkali or organic solvent, etc., as well as cleaning pieces 7 comprising resin such as Teflon, etc., in diameter of 1-2mm mixed with the cleaning solution 12 by a circulation pump 5. Furthermore, the fed cleaning solution 12 and the cleaning pieces 7 scrub-clean up both surfaces of the wafers 1 contained in a carrier 2 and then fed-back from the outer vessel 3b to a circulation vessel. Accordingly, both surfaces of the wafers 1 are cleaned up with the cleaning solution 12 mixed with the cleaning pieces 7 so that the defects due to any dust, stain, etc., may be prevented from being developed in the next process.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for cleaning semiconductor wafers.

[Conventional technology]

Conventionally, a cleaning apparatus shown in FIG. 4 has been used to clean semiconductor wafers (hereinafter simply referred to as wafers).

That is, while rotating the wafer 1 held by the chuck 13, the cleaning liquid 1 is applied to the wafer surface from the nozzle 12a.
Supply 2. Then, by rotating the cleaning brush 11 and bringing it into contact with the wafer surface, dust, dirt, etc. on the wafer surface is cleaned. Here, 14 and 15 are conveyor belts, respectively.

[Problem to be solved by the invention]

The conventional cleaning method described above cleans only the front surface of the wafer, and due to dust and dirt adhering to the backside of the wafer during wafer transport, these dusts and dirt can be deposited on the wafer surface during wafer processing in the next process. Re-adhesion was the main cause of low yield.

[Means to solve the problem]

The semiconductor wafer cleaning method of the present invention uses a cleaning device that circulates a cleaning liquid consisting of a chemical between a cleaning tank and a circulation tank,
In a semiconductor wafer cleaning method in which the semiconductor wafer is cleaned by immersing it in a cleaning tank, a resin cleaning piece is mixed into the cleaning liquid.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a cleaning device for explaining an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the cleaning tank shown in FIG. 1.

The cleaning tank 3 is composed of an inner tank 3a and an outer tank 3b.

The inner tank 3a is heated by the circulation pump 5 to remove acids, alkalis, etc.
Alternatively, a cleaning liquid 12 made of an organic solvent or the like and a cleaning piece 7 made of a resin such as Teflon with a diameter of 1 to 2 mm mixed in the cleaning liquid are fed to cause an overflow. In addition, the supplied cleaning liquid 12 and cleaning piece 7 are
After scrubbing both sides of the wafer 1 housed in the carrier 2, the wafer 1 is returned to the circulation tank 6 from the outer tank 3b.

As described above, according to this embodiment, since both sides of the wafer 1 are cleaned by the cleaning liquid 12 mixed with the cleaning piece 7, defects due to dust, dirt, etc. will not occur in the next process.

In addition, as shown in FIG. 3, the carrier 2 that stores the wafer 1 may be made to be able to swing up and down in the cleaning tank using a swinging arm 10. In this case, the wafer 1 is always allowed to swing up and down. Because it can enhance the scrubbing effect,
It has the advantage of being able to be cleaned in a short time.

〔Effect of the invention〕

As described above, according to the present invention, both sides of the wafer can be efficiently cleaned simultaneously while the wafer is housed in the carrier, so that it is possible to prevent dust, dirt, etc. from adhering to the back surface of the wafer during wafer transport. In addition, by cleaning both sides of the wafer, it is possible to prevent dust and dirt from being brought in from the back side of the wafer in the conventional next process and re-adhering to the wafer surface, which has a large effect on improving yield.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram of a cleaning apparatus for explaining an embodiment of the present invention, FIGS. 2 and 3 are enlarged sectional views of the cleaning tank shown in FIG. 1, and FIG. 4 is a conventional wafer cleaning device. FIG. 2 is a block configuration diagram of a cleaning device for explaining a cleaning method. Process: Wafer, 2: Carrier, 3: Washing tank, 3a: Inner tank, 3b: Outer tank, 4: Washing tank,
5...Circulation pump, 6...Circulation tank, 7...Cleaning piece, 8...Liquid supply piping, 9...Drainage piping, 10...Swing arm, 11...Washing Brush, 12a... Nozzle, 12... Cleaning liquid, 13... Chuck, 14...
Load belt, 15... Unload belt, 16...
- Supply carrier, 17... storage carrier.

Claims (1)

[Claims] In a semiconductor wafer cleaning method that uses a cleaning device that circulates a cleaning solution consisting of a chemical solution between a cleaning tank and a circulation tank and performs cleaning by immersing the semiconductor wafer in the cleaning tank, a resin cleaning piece is mixed into the cleaning solution. A method for cleaning semiconductor wafers, characterized by: