Brushing – scrubbing – and general cleaning – Machines – Brushing
Reexamination Certificate
1999-03-05
2001-04-24
Spisich, Mark (Department: 1744)
Brushing, scrubbing, and general cleaning
Machines
Brushing
C015S088200
Reexamination Certificate
active
06219872
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a brush scrubbing apparatus, and more particularly, the present invention relates to the brush scrubbing apparatus for a semiconductor wafer.
This application is a counterpart of Japanese application Serial Number 57166/1998, filed Mar. 9, 1998, the subject matter of which is incorporated herein by reference.
2. Description of the Related Art
In general, a conventional brush scrubbing apparatus has been used for scrubbing a semiconductor wafer. The conventional brush scrubbing apparatus has been disclosed in “SILICON WAFER HYOMEN NO KURINKA-GIJYUTU, KENJI SUGIMOTO et al, REALIZE INC, pp. 293-294”, and Japanese Patent Laid Open No.8-206617.
In the conventional brush scrubbing apparatus, a rotating brush pushes to the surface of the semiconductor wafer and moves along it while a cleaning solution such as deionized water is supplied to the rotating brush. As a result, the conventional brush scrubbing apparatus removes particles hydrodynamically while the rotating brush rubs the surface of the semiconductor wafer.
More particularly, the conventional brush scrubbing apparatus retains the semiconductor wafer on a rotating turntable. The semiconductor wafer turns on a vertical axis while the deionized water is supplied to the surface of the semiconductor wafer. In this circumstances, a rotating brush mounted on a bottom portion of an arm, which moves above the semiconductor wafer, then contacts the surface of the semiconductor wafer via the dieionized water, and then is thrust toward the surface of the semiconductor wafer. And then the rotating brush moves along the surface of the semiconductor wafer. As a result, the conventional brush scrubbing apparatus removes particles.
In the conventional brush scrubbing apparatus, the brush is thrust downward a predetermined distance from a reference position of brush, which influences a cleaning effect and may cause damage to the semiconductor wafer. The reference position is a position that the rotating brush contacts the surface of the semiconductor wafer. The reference position is set with an eye measurement. When adjusting the predetermined distance, it is important to set the reference position precisely.
In the conventional brush scrubbing apparatus, it is desirable to precisely get the reference position for deciding the predetermined distance without using the eye measurement.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a brush scrubbing apparatus that can precisely set a position as the reference position, where the brush contacts the surface of the semiconductor wafer without using an eye measurement.
According to one aspect of the present invention, for achieving the above object, there is provided a brush scrubbing apparatus comprising: a rotating turntable which retains a wafer; a brush which removes a particle on the wafer; and a controller which detects a reference position responding to a change of a driving current value for driving the brush, and which stores a predetermined distance to thrust downward from the reference position; wherein the reference position is a position which the brush contacts to the wafer.
According to another aspect of the present invention, for achieving the above object, there is provided a brush scrubbing apparatus comprising: a rotating turntable which retains a wafer; a brush which removes a particle on the wafer; and a controller which detects a reference position responding to a change of a first current value for driving the brush, which stores a predetermined distance to thrust downward from the reference position, and, and which stores a second current value for driving the brush when making go down the brush until the predetermined distance to thrust downward from the reference position, and which finds a differential value between the first and second current values and compares between the differential value and a predetermined threshold value; wherein the reference position is a position which the brush contacts to the wafer.
According to another aspect of the present invention, for achieving the above object, there is provided a brush scrubbing apparatus comprising: a rotating turntable which retains a wafer; a brush which removes a particle on the wafer; a controller which detects a reference position responding to a change of a driving current value for driving the wafer, and which stores a predetermined distance to thrust downward from the reference position; wherein the reference position is a position which the brush contacts to the wafer.
According to another aspect of the present invention, for achieving the above object, there is provided a brush scrubbing apparatus comprising: a brush holder; a brush; and a controller which detects a reference position responding to a change of a driving current value for driving the brush; wherein the reference position is a position which the brush contacts to the brush holder.
According to another aspect of the present invention, for achieving the above object, there is provided a brush scrubbing apparatus comprising: a rotation holder; a brush; a tachometer which detects a rotation speed of the brush via the rotation holder; and a controller which detects a reference position responding to a signal when the brush contacts to the rotation holder.
REFERENCES:
patent: 4382308 (1983-05-01), Curcio
patent: 4993096 (1991-02-01), D'Amato
patent: 5012526 (1991-05-01), Romans et al.
patent: 5475889 (1995-12-01), Thrasher et al.
patent: 5829087 (1998-11-01), Nishimura et al.
patent: 5943726 (1999-08-01), Eitoku et al.
patent: 5-301082 (1993-11-01), None
patent: 6-464 (1994-01-01), None
patent: 8-206617 (1996-08-01), None
Kenjui Sugimoto et al., Silicon Wafer Hyomen No Kurinka-Gijyutu, pp. 293-295, Realize Inc.
Osako Takashi
Ueki Koji
OKI Electric Industry Co., Ltd.
Rabin & Champagne PC
Spisich Mark
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