Information
-
Patent Grant
-
6334581
-
Patent Number
6,334,581
-
Date Filed
Thursday, September 28, 200023 years ago
-
Date Issued
Tuesday, January 1, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Scherbel; David A.
- Hwu; Davis
Agents
-
CPC
-
US Classifications
Field of Search
US
- 239 589
- 239 600
- 239 5871
- 239 5875
- 239 5872
- 239 69
- 222 533
- 222 522
- 222 568
- 901 43
-
International Classifications
- B05B1508
- B05B100
- A62C3102
-
Abstract
A spray nozzle resetting device comprises a spray nozzle for spraying resist onto a midpoint of a wafer, a rotary robotic arm that has a resist-delivering duct connected to the spray nozzle, a covering nut, a resetting ring, and a fixing ring. The covering nut has an opening of diameter D. The resetting ring has a rotary part of a diameter less than or equal to D, which fits in the opening of the covering nut, and at least two protrusions. The fixing ring, having two recesses that correspond to the two protrusions and interact with them, is used to connect the covering nut and the rotary robotic arm.
Description
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention provides a resist spray nozzle resetting device, namely a device for achieving uniformity of resist coating on a semiconductor wafer.
2. Description of the Prior Art
In semiconductor manufacturing processes, a semiconductor wafer must go through many coating processes from start to finish, such as lithographic resist and developer coating processes. With the narrowing line width in semiconductor processes, photolithographic technology has become critical, for it is with photolithography that all the MOS components, metallic wires, thin film patterns and dopant regions are made. Moreover, the pattern-transferring process, mandatory in photolithography, is complicated and subtle, and so only a precise pattern of resist can ensure the reliability of later processes.
In today's market, most resist coating processes are performed by spin-coating liquid resist over a wafer to form a resist layer with an even thickness. This forms a light-sensitive photo-emulsion layer. Since the uniformity of the thickness of a resist layer can later affect the resolution, the depth of focus (DOF), and even the quality of the wafer, it is important in wafer production to know how to achieve and maintain the uniformity of the resist layer.
Please refer to FIG.
1
.
FIG. 1
is a front view of a resist coating device
10
according to the prior art. As shown here, the resist coating device
10
comprises a rotary robotic arm
12
and a spray nozzle
14
. The spray nozzle
14
has a covering nut
16
fastened on the rotary arm
12
. The spray nozzle
14
sprays resist
18
over a wafer's surface
20
which, positioned on a vacuum rotary station
22
, is kept in rotating motion. Ideally, the spray nozzle aims straight at the midpoint
26
of the wafer
20
; in other words, it forms a line with the central axis
24
, so that the resist
18
drops directly on the midpoint
26
of the wafer
20
and coats the wafer surface. Unfortunately, sometimes the spray nozzle
14
might move astray from the center axis
24
due to maintenance errors or operating negligence, causing the resist
18
to fall off the midpoint
26
, resulting in a non-uniform resist coating. Even though resetting of the spray nozzle
14
can be done manually, if it is off of the central axis
24
, it wastes both time and money, and alignment errors after manual resetting are not negligible.
SUMMARY OF THE INVENTION
The purpose of the present invention is to provide a spray nozzle resetting device to correct the weaknesses of the conventional counterpart described above.
Another purpose of the present invention is to provide a spray nozzle resetting device to avoid misalignment problems, so as to improve the uniformity of the resist layer.
In a preferred embodiment of the present invention, a spray nozzle resetting device comprises a spray nozzle for spraying resist on the midpoint of a wafer, a rotary robotic arm, a resist-delivering duct connected to one end of the spray nozzle, a covering nut, a resetting ring, a fixing ring connecting the covering nut to the rotary robotic arm, and a spring positioned between the covering nut and the resetting ring. The covering nut has an opening of diameter D. The resetting ring has a rotary part with a diameter equal to or less than D, and at last two protrusions. The rotary part fits in the opening of the covering nut. The fixing ring is used to fix the covering nut to the rotary robotic arm, and it has two recesses corresponding to the two protrusions to interact with the two protrusions.
In the preferred embodiment, the midpoint of the resetting ring is not aligned with the two protrusions. To move the spray nozzle, the operator can lift up the rotary part of the fixing ring and rotate it to a desired angle, with the spray nozzle rotating along with it. For performing the resist coating process, the operator can rotate the rotary part in the reverse direction until the two protrusions re-catch on the two recesses, so as to again aim the spray nozzle at the midpoint of the wafer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a front view of a resist spray nozzle according to the prior art.
FIG. 2
is an exploded diagram of a spray nozzle resetting device according to the present invention.
FIG. 3A
is a side view of a resetting ring of the present invention.
FIG. 3B
is a front view of a resetting ring of the present invention.
FIG. 3C
is a rear view of a resetting ring of the present invention.
FIG. 4A
is a cross-sectional view of a fixing ring of the present invention.
FIG. 4B
is a front view of a fixing ring of the present invention.
FIG. 5
is a perspective view of a spray nozzle resetting device according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Please refer to FIG.
2
.
FIG. 2
is an exploded diagram of a spray nozzle resetting device
30
according to the present invention. As shown here, the spray nozzle resetting device
30
comprises a spray nozzle
34
bent at a 90 degree angle that is used to spray resist on the midpoint of a wafer, a rotary robotic arm
32
for resist delivery, a covering nut
36
with an opening
36
a
of diameter D, a spring
44
, a resetting ring
38
and a fixing ring
42
for connecting the covering nut
36
to the rotary robotic arm
32
. The spring
44
is located between the covering nut
36
and the resetting ring
38
, and is fixed resiliently on the rotary part
38
a
, providing a tightening force between the resetting ring
38
and the fixing ring
42
. The rotary robotic arm
32
has a resist-delivering duct
32
a
connected to one end of the spray nozzle
34
.
In the preferred embodiment, the spray nozzle
34
is made of stainless steel, and is bent at
90
degrees. Additionally, the spraying end of the spray nozzle
34
is equipped with a plastic head
34
a
. The spray nozzle
34
of the present invention, however, is not restricted to this particular material and bending angle. Other materials and bending angles can be used for the spray nozzle
34
.
Please refer to
FIG. 3A
, which is an enlarged side view of the resetting ring
38
according to the present invention. The resetting ring
38
comprises a rotary part
38
a
on one side, and at least two protrusions
38
b
on the opposite side. The rotary part
38
a
fits into the opening
36
a
of the covering nut
36
. Additionally, the rotary part
38
a
has at least one screw hole
38
c
that accommodates a bolt to secure the spray nozzle
34
. The resetting ring
38
has in its center a hole
38
d
to accommodate the spray nozzle
34
. The hole
38
d
extends through the resetting ring
38
, including the rotary part
38
a
. There are in the rotary part
38
a
two screw holes
38
c
going through the hole
38
d
for securing the spray nozzle
34
with a screw bolt, making the spray nozzle
34
and the rotary part
38
a
rotate together.
Please refer to
FIG. 3B
, which is a front view of the resetting ring
38
according to the present invention. The rotary part
38
a
is located on one side of the resetting ring
38
, and the two protrusions
38
b
are on the opposite side. The diameter of the rotary part
38
is equal to or less than D, so that it may pass through the opening
36
a
of the covering nut
36
.
“Please refer to
FIG. 3C
, which is a rear view of the resetting ring
38
according to the present invention The two protrusions
38
b
and
38
e
have distances of d
1
and d
2
from the center of the circle, respectively. In the preferred embodiment, d
1
is not equal to d
2
, and d
1
and d
2
are less than the diameter
39
of the resetting ring
38
. Additionally, the two protrusions
38
b
and
38
e
are not aligned together with the center point of the circle.”
“Please refer to FIG.
4
A and FIG.
4
B. FIG.
4
A and
FIG. 4B
are, respectively, a cross-sectional side view and a front view of the fixing ring
42
according to the present invention. As shown in
FIG. 4A
, the fixing ring
42
comprises a front part
45
and a rear part
46
. The front part
45
is screwed tightly to the covering nut
36
, and the rear part
46
to the rotary robotic arm
32
. In other words, the main function of the fixing ring
42
is to join together the covering nut
36
and the rotary robotic arm
32
. Moreover, the fixing ring
42
has in its center an opening
42
a
that accommodates the spray nozzle
34
and the resist-delivering duct
32
a
. There are two screw holes
42
b
in the rear part
46
for securing the resist-delivering duct
32
a
, which runs across the rear part.”
The fixing ring
42
has an the inner side
47
of the rear part
45
two recesses
42
c
, which correspond to and interact with the two protrusions
38
b
of the resetting ring
38
. In the preferred embodiment, the center point of the fixing ring
42
is not aligned with the two recesses
42
c
. As shown in FIG.
3
C and
FIG. 4B
, the diameter
43
of the inner circle of the front part
45
of the fixing ring
42
is slightly longer than the diameter
39
(in
FIG. 3C
) of the resetting ring
38
.
What is worth noticing is that because the distances d
1
and d
2
from the two protrusions
38
b
and
38
c
to the center point of the circle, respectively, are not the same, and because the two protrusions
38
b
and
38
c
, and the center point of the resetting ring
38
are not aligned, the spray nozzle can have only one reset position.
Please refer to
FIG. 5
, which is a perspective view of the spray nozzle resetting device
30
according to the present invention. As shown here, to move the spray nozzle
34
for regular maintenance, the operator first pulls out the rotary part
38
a
in the direction of the arrow
51
, and rotates it clockwise or counter clockwise through an angle. Since the spray nozzle
34
has been screwed securely to the rotary part
38
a
, the spray nozzle
34
moves together through the same angle as the rotary part
38
a
. When the operator releases the rotary part
38
a
, the resetting ring
38
and the fixing ring
42
are kept in contact by the force provided by he spring
44
, allowing the spray nozzle
34
and the resetting device
30
to remain in the maintenance position. After the maintenance procedure has been completed, and when the operator needs to run another resist coating process, he or she may rotate the rotary part
38
a
in the reverse direction until the two protrusions
38
b
re-catch the two recesses
42
c
, ensuring that the spray nozzle
34
points at the midpoint
86
of the wafer
80
, and aligning it with the center axis.
It should be remembered that before using the spray nozzle resetting device
30
, the operator should correct the spray nozzle
34
by aiming it at the midpoint
86
of the wafer
80
and aligning it with the center axis
84
. It is only after the correction that the operator may secure with screw bolts the spray nozzle
34
to the rotary part
38
a
of the resetting ring
38
. In this manner, the operator ensures that the spray nozzle points precisely at the midpoint
86
of the wafer
80
for each run.
In comparison to the prior art, the present invention is superior in that it solves the resetting problem of the spray nozzle
34
, which the operator often encounters after a maintenance procedure. Because of this invention, the spray nozzle
34
can now be accurately aimed at the midpoint
86
of the wafer
80
in resist coating processes, thus improving the uniformity of resist and the reliability of the later photolithographic processes.
The above disclosure is based on the preferred embodiment of the present invention. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Claims
- 1. A resist spray nozzle reposition device comprising:a spray nozzle with an approximately rectangular shape being used to spray resist onto a midpoint of a spinning semiconductor wafer; a rotary robot arm comprising a resist-transmitting line, the resist-transmitting line connected to an end of the spray nozzle; a covering nut having an opening with a diameter D; a reposition ring comprising a rotary part with a diameter less than or equal to D, and at least two protrusions, the rotary part positioned through the opening of the covering nut; a fixing ring used to connect the covering nut and the rotary robot arm, the fixing ring comprising two recesses that are positioned to correspond with the two protrusions; and a spring used to provide a force to keep the reposition ring in tight contact with the fixing ring, the spring being positioned between the covering nut and the reposition ring; wherein to move the spray nozzle, the rotary part of the reposition ring is pulled out against the force of the spring and rotated together with the spray nozzle by an angle, and by continuing to rotate the rotary part, the spray nozzle can be self-aligned and repositioned on the midpoint of the semiconductor wafer due to interaction between the protrusions and the recesses.
- 2. The spray nozzle reposition device of claim 1 wherein at least one screw is used to fix the spray nozzle on the rotary part of the reposition ring so that the spray nozzle and the rotary part are rotated together.
- 3. The spray nozzle reposition device of claim 1 wherein the spray nozzle has a right-angled shape.
- 4. The spray nozzle reposition device of claim 1 wherein the spray nozzle is made of stainless steel.
- 5. The spray nozzle reposition device of claim 1 wherein the spray nozzle further comprises a plastic head positioned on another end of the spray nozzle.
- 6. The spray nozzle reposition device of claim 1 wherein a midpoint of the reposition ring is not aligned with the two protrusions.
- 7. The spray nozzle reposition device of claim 1 wherein a midpoint of the fixing ring is not aligned with the two recesses.
- 8. A liquid process spray nozzle reposition device used in the manufacturing of semiconductor devices, the liquid process spray nozzle reposition device comprising:a spray nozzle with an approximately rectangular shape; a rotary robot arm comprising a liquid-transmitting line, the liquid-transmitting line connected to an end of the spray nozzle; a covering nut having an opening with a diameter D; a reposition ring comprising a rotary part with a diameter less than or equal to D, and at least two protrusions; a fixing ring used to connect the covering nut and the rotary robot arm, the fixing ring comprising two recesses that are positioned to correspond to the two protrusions; and a spring that provides a force to keep the reposition ring tightly in contact with the fixing ring, the spring being positioned between the covering nut and the reposition ring.
- 9. The spray nozzle reposition device of claim 8 wherein at least one screw on the rotary part of the reposition ring fixes the spray nozzle so that the spray nozzle and the rotary part are rotated together.
- 10. The spray nozzle reposition device of claim 8 wherein the spray nozzle has a right-angled shape.
- 11. The spray nozzle reposition device of claim 8 wherein the spray nozzle is made of stainless steel.12.The spray nozzle reposition device of claim 8 wherein the spray nozzle further comprises a plastic head positioned on another end of the spray nozzle.
- 13. The spray nozzle reposition device of claim 8 wherein a midpoint of the reposition ring is not aligned with the two protrusions.
- 14. The spray nozzle reposition device of claim 8 wherein a midpoint of the fixing ring is not aligned with the two recesses.
US Referenced Citations (5)
Number |
Name |
Date |
Kind |
3107056 |
Hunter |
Oct 1963 |
A |
4634052 |
Grizzle et al. |
Jan 1987 |
A |
4723713 |
Dahlquist |
Feb 1988 |
A |
5088628 |
Knickerbocker |
Feb 1992 |
A |
5161716 |
Knickerbocker |
Nov 1992 |
A |