Cleaning and liquid contact with solids – Apparatus – With means to movably mount or movably support the work or...
Reexamination Certificate
2000-08-11
2001-08-21
Coe, Philip R. (Department: 1746)
Cleaning and liquid contact with solids
Apparatus
With means to movably mount or movably support the work or...
C134S902000
Reexamination Certificate
active
06276378
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for cleaning both sides of substrates, such as LCD substrates or semiconductor wafers.
In a process for manufacturing semiconductor devices, both sides of semiconductor wafers must be cleaned. Therefore, contamination, such as particles, organic contaminants and metal impurity, allowed to adhere to the both sides of the wafers must be removed. To remove contamination from the both sides of the semiconductor wafers, a single wafer type apparatus for cleaning both sides of semiconductor wafers has been employed with which semiconductor wafers are sequentially processed.
As the apparatus for cleaning both surfaces of semiconductor wafer, there are apparatuses of two types, i.e., a reversing type wherein the front-side and the back-side surfaces of wafer are cleaned independently, and a non-reversing type wherein both-side surfaces are cleaned simultaneously.
Since the apparatus of the reversing type (the former) is provided with a reversing unit for reversing the wafer W in addition to the cleaning unit, it becomes large-sized and has low throughput.
As shown in
FIG. 1
, a conventional apparatus
100
for cleaning both sides of wafers incorporates a cup
108
disposed in a case
109
, a spin chuck
101
, a motor
102
, a back-side cleaning mechanism
106
and a front-side cleaning mechanism (not shown). The spin chuck
101
is connected to a rotational drive shaft
103
of the motor
102
, the spin chuck
101
incorporating four support arms
104
radially extending from the center of rotation of the spin chuck
101
and holding members
105
. Each of the holding members
105
is joined to the leading end of each of the support arms
104
. The foregoing holding members
105
are brought into contact with an outer end of a wafer W so as to horizontally hold the wafer W. The back-side cleaning mechanism
106
is disposed below the spin chuck
101
. The back-side cleaning mechanism
106
has a nozzle
107
for discharging and supplying process liquid to the back side of the wafer W.
As shown in
FIG. 2
, the nozzle
107
supplies the process liquid to the back side of the wafer W through a space
110
between the support arms
104
of the spin chuck
101
. However, a gas-liquid interface is undesirably generated on the back side of the wafer W on which the supply of the process liquid to the same is obstructed by the support arms
104
. Thus, the back side of the wafer W cannot sufficiently be rinsed. What is worse, foreign matter, such as particles, can easily be allowed to adhere to the portion in the vicinity of the gas-liquid interface. Thus, there is apprehension that the back side of the wafer W is contaminated. Moreover, the rotating support arms
104
reject the process liquid, thus causing a great quantity of the process liquid to be consumed wastefully. Thus, the running cost is enlarged excessively.
As a conventional apparatus of another type, an apparatus
120
for rinsing two sides of wafers is known, the apparatus
120
incorporating a nozzle
126
structured as shown in
FIG. 3. A
rotational table
124
arranged to be rotated by a rotating mechanism
130
is disposed in a cup
121
of the apparatus
120
. A nozzle
126
is disposed to face a central portion of the back side of a wafer W held by the rotational table
124
. The rotating mechanism
130
is provided with a motor
134
, a driving pulley
133
, an idle pulley, a belt
132
, and a rotating shaft
123
. The rotational driving force of the motor
134
is transmitted to the rotating shaft
123
through the belt
132
. A supply pipe
125
of the nozzle
126
passes through a rotating shaft
123
, and then the supply pipe
125
is allowed to communicate with a process liquid supply unit (not shown).
The process liquid splattered from the rotating wafer W generates a great quantity of splashes of the process liquid in the cup
121
. On the other hand, particles are generated in the rotating mechanism
130
. To prevent contamination of the wafer W, the communication between the processing atmosphere in the cup
121
and the atmosphere in the rotating mechanism
130
must be prevented.
However, a small gap
127
exists between the rotating shaft
123
and the cup
121
. Therefore, fine dust generated in the rotating mechanism
130
is introduced from the rotating mechanism
130
into the cup
121
through the gap
127
. Thus, the introduced dust is allowed to adhere to the back side of the wafer W. Splashes of the process liquid is introduced into the rotating mechanism
130
from the cup
121
through the small gap
127
. Thus, the rotating mechanism
130
is contaminated. Since a small gap
128
exists in a portion in which the nozzle
126
projects over the rotational table
124
, the process liquid is introduced into the supply pipe
125
through the gap
128
. Thus, the rotating mechanism
122
disposed below the supply pipe
125
is contaminated. As a result, the rotating mechanism
130
easily produces trouble.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide an apparatus for cleaning both sides of substrate with which contamination of the back side of the substrate can be prevented and which is able to improve the efficiency to clean the back side of the substrate, and which provides a high throughput and is small-sized.
Another object of the present invention is to provide an apparatus for cleaning both sides of substrates with which contamination of the back sides of the substrates can be prevented and a rotating mechanism of a spin chuck is not contaminated.
An apparatus for cleaning both sides of a substrate, comprising: a spin chuck for holding a substrate such that contact with at least a central portion of the substrate is prevented; rotating means having a hollow shaft connected to the spin chuck to transmit rotating force to the spin chuck; front-side cleaning means for cleaning a front side of the substrate held by the spin chuck; and back-side cleaning means for cleaning a back side of the substrate held by the spin chuck, wherein the back-side cleaning means is disposed to face the back-side of the substrate held by the spin chuck through hollow portions of the hollow shaft.
An apparatus for cleaning both sides of a substrate, comprising: a rotational table having a holding portion for holding a substrate such that contact with at least a central portion of the substrate is prevented; a hollow rotating shaft connected to a lower portion of the rotational table and rotatively supporting the rotational table; front-side cleaning means for cleaning a front side of the substrate held by the rotational table; back-side cleaning means for cleaning the back side of the substrate held by the rotational table, the back-side cleaning means having a nozzle disposed to face the back side of the substrate held by the rotational table through a hollow portion of the rotating shaft; a process liquid supply unit for supplying process liquid to the nozzle; a cover for covering the hollow rotating shaft; and a first sealing member for sealing a portion between the cover and the rotational table.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
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patent: 5061144 (1991-10-01), Akimoto et al.
patent: 5081733 (1992-01-01), Kudo
patent: 5092011 (1992-03-01), Gommori et al.
patent: 5144711 (1992-09-01), Gill, Jr.
patent: 5213118 (1993-05-01), Kamikawa
patent: 5226437 (1993-07-01), Kamikawa
patent: 5236515 (1993-08-01), Ueno et al.
patent: 5261431 (1993-11-01), Ueno et al.
patent: 5278821 (1994-01-01), Kawamura et al.
patent: 5282289 (1994-02-01), Hasegawa et al.
patent: 5297910 (1994-03-01), Yoshioka et al.
patent: 5327921 (1994-07-01), Mokuo et al.
Arihisa Toshikazu
Taniyama Hiroki
Coe Philip R.
Morrison & Foerster
Tokyo Electron Limited
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