Brushing – scrubbing – and general cleaning – Machines – Brushing
Reexamination Certificate
2001-03-07
2004-11-02
Chin, Randall (Department: 1744)
Brushing, scrubbing, and general cleaning
Machines
Brushing
C015S021100, C015S088200, C015S088300
Reexamination Certificate
active
06810548
ABSTRACT:
FIELD OF THE INVENTION
The present invention generally relates to a cleaning apparatus for precision cleaning of various products made of semiconductor, glass, plastic, metal, etc., such as an IC (Integrated Circuit) wafer, a semiconductor wafer of the IC wafer, a liquid crystal panel, a glass substrate of the liquid crystal panel, a plasma display, a glass substrate of the plasma display, an optical device, an optical fiber, precision components (metal precision components) for semiconductor, or the like, and more particularly relates to a cleaning apparatus for precision cleaning of such products using a cleaning brush and an ultrasonic vibrator.
BACKGROUND OF THE INVENTION
For the precision processing of substrates such as glass substrates for a semiconductor wafer, a liquid crystal panel, etc., is generally performed in the following manner. Wires, an insulating film, and a film such as a semiconductor layer, etc., are formed, and the structure as desired is produced by a similar technique to the photographic printing technique, called photolithography. However, when performing precision processing by photolithography, the problem arises in that particulate contaminant (dust particles) adhering to the surface of the substrate causes defects such as disconnection, shorting, and inferior patterning, which lower the yield.
Therefore, conventionally, the substrate is always subjected to the precision cleaning before precision-processing it by the photolithography, and for this precision cleaning of the substrate, various cleaning apparatuses have been proposed.
In the conventional cleaning apparatus, a brush cleaning vessel and an ultrasonic cleaning vessel are provided separately, and a brush scrubbing cleaning and an ultrasonic cleaning are performed independently in the brush cleaning vessel and the ultrasonic cleaning vessel respectively. For this structure, the conventional cleaning apparatus is required to have a large size, and a large footprint (area of the bottom surface of the apparatus).
As an example of such conventional cleaning apparatus, a conveyer-type single wafer cleaning apparatus will be explained in reference to FIG.
5
and FIG.
6
.
This type of conventional cleaning apparatus is provided with a brush cleaning vessel
101
illustrated in FIG.
5
. As illustrated in
FIG. 5
, the brush cleaning vessel
101
includes a roll brush
102
for cleaning a substrate
110
, shower nozzles
103
for blowing an aqueous cleaning agent
111
against the substrate
110
for shower-cleaning, and transport rollers
104
for transporting the substrate
110
in a horizontal direction.
The roll brush
102
has a rotation mechanism (not shown) and scrubs the upper surface of the substrate
110
while rotating thereon for brush cleaning. The shower nozzles
103
are provided for applying the aqueous cleaning agent
111
onto the surface of the substrate
110
by blowing thereto the aqueous cleaning agent
111
and also for shower-cleaning the surface of the substrate
110
. The transport rollers
104
are provided for transporting the substrate
110
in the horizontal direction while rotating on the lower surface of the substrate
110
. The brush cleaning vessel
101
is provided in the cleaning apparatus as an independent vessel. After the brush cleaning is performed in the cleaning vessel
101
, the substrate
110
is placed in the ultrasonic cleaning vessel
105
illustrated in
FIG. 6
for the subsequent ultrasonic cleaning.
As shown in
FIG. 6
, the ultrasonic cleaning vessel
105
includes an ultrasonic nozzle
106
for ultrasonically cleaning the substrate
110
from thereabove, and transport rollers
107
for transporting the substrate
110
in the horizontal direction.
The ultrasonic nozzle
106
blows the aqueous cleaning agent
111
from its leading end against the upper surface of the substrate
110
and ultrasonically vibrates the aqueous cleaning agent
111
by means of an ultrasonic vibrator (not shown) stored therein, thereby ultrasonically cleaning the upper surface of the substrate
110
. The transport rollers
107
are provided for transporting the substrate
110
in the horizontal direction while rotating on the lower surface of the substrate
110
.
As described, in the conventional cleaning apparatus, the brush scrubbing cleaning and the ultrasonic cleaning are performed in different vessels respectively. However, in the conventional cleaning apparatus of the foregoing structure, the removal of particulate contamination (dust particles) to the sufficient level of cleanliness cannot be ensured. Moreover, an overall footprint area of the cleaning apparatus becomes larger.
In response, another cleaning apparatus has been proposed wherein brush cleaning and ultrasonic cleaning are performed in the same vessel.
For example, Japanese Unexamined Patent Publication No. 87288/1999 (Tokukaihei 11-87288) published on Mar. 30, 1999 discloses a substrate cleaning apparatus wherein a cleaning brush and an ultrasonic nozzle are provided in parallel on one side of the substrate, so that the brush scrubbing cleaning and the ultrasonic cleaning can be performed simultaneously to effectively remove from the surface of the substrate the particulate contamination (dust particles) as well as fiber particles released from the cleaning brush.
Japanese Unexamined Patent Publication No. 86222/1995 (Tokukaihei 7-86222) published on Mar. 31, 1995 discloses another substrate cleaning apparatus wherein a cleaning brush and an ultrasonic nozzle are provided adjacently to improve the cleaning power of the substrate and at the same time to suppress the contamination of the cleaning brush.
Japanese Unexamined Patent Publication No. 5577/1994 (Tokukaihei 6-5577) published on Jan. 14, 1994 discloses still another substrate cleaning apparatus which performs a brush scrubbing cleaning in a cleaning vessel, wherein an overflow vessel storing therein an ultrasonic vibrator is adopted as a cleaning vessel to eliminate the problem of the contamination of the cleaning brush.
However, according to the cleaning apparatus of Japanese Unexamined Patent Publication No. 87288/1999, the cleaning brush and the ultrasonic nozzle always clean different parts of the substrate as is clear when thinking about only one particular part on the surface of the substrate. Specifically, for example, immediately after the cleaning brush has passed on the part for the brush cleaning, the ultrasonic nozzle passes that part for the ultrasonic cleaning. Therefore, precisely speaking, these two kinds of cleaning system are not applied to one part simultaneously but sequentially in a short time.
The foregoing structure merely offers an effect as achieved by reducing the switch time from the brush cleaning to the ultrasonic cleaning, i.e., the likelihood of the problem that the fibrous particles adhering to the substrate are dried and become difficult to be removed from the surface of the substrate can be suppressed. In this structure, however, an improvement in removing power of particulate contamination (dust particles) as well as an improvement in suppressing a reduction in yield due to the particulate contamination (dust particles) can be hardly expected as compared to the aforementioned cleaning apparatus of the structure wherein the brush cleaning and the ultrasonic cleaning are performed independently in different vessels. Therefore, the foregoing cleaning apparatus cannot provide a sufficient level of cleanliness to meet the increasing demand for cleaning of an improved precision (fineness).
Moreover, in the foregoing structure, the cleaning brush and the ultrasonic nozzle are provided in parallel on the same plane, and thus the cleaning brush itself is not subjected to the ultrasonic cleaning. Therefore, the longer is the operation time of the cleaning apparatus, the more is likely that the cleaning brush takes in the particulate contamination (dust particles) once removed out of the substrate surface, and such contamination once captured by the cleaning brush are redeposited on the surface of the substrate. There
Hara Takeshi
Kobayashi Kazuki
Ono Hitoshi
Yoshioka Hiroto
Chin Randall
Conlin David G.
Edwards & Angell LLP
Hatnell, III George W.
Sharp Kabushiki Kaisha
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