Patent US4640846A successfully refreshed from Google Patents.
US4640846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor spin coating method
Assignee: Individual
•
Filing: 1984-09-25
•
Granted: 1987-02-03
•
Expires: 2004-09-25
Abstract
Abstract An improved method for coating a semiconductor wafer with a uniform layer of photoresist or other liquid film is provided. The liquid is first semi-uniformly deposited on the wafer by spraying or otherwise. Thereafter, the wafer is rotated about an axis perpendicular to the plane of the wafer and removed from the wafer. In the preferred embodiment, a number of wafers are placed about the perimeter of a large, flat disc which is rotated about its center. The liquid is spread over the surface of each wafer by the centrifugal force generated by such rotation. By placing the wafers at a distance from the axis of rotation, the centrifugal force on all points of each wafer is approximately the same, thereby providing for a uniform spreading of the film over the wafer.
Inventors
- 👤 Yue Kuo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:45
CPC Classifications
B; B05; B05D; B05D1/00; B05D1/002; B05D1/005; G; G03; G03F; G03F7/00; G03F7/16; G03F7/162
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
81 words
A method for coating semiconductor wafers with a liquid film comprising: first, depositing a continuous non-uniform layer of the liquid film on the top of the wafers; second, rotating the wafers about an axis perpendicular to the plane of the wafers and removed from the wafers to spread said film substantially uniformly across said wafers; and third, preventing liquid film deposited on one wafer from contacting another wafer during said rotation without reflecting said liquid film back onto said first wafer.
Claim 2
Independent Claim
81 words
A method for coating semiconductor wafers with a liquid film comprising: first, depositing a continuous non-uniform layer of the liquid film on the top of the wafers; second, rotating the wafers about an axis perpendicular to the plane of the wafers and removed from the wafers to spread said film substantially uniformly across said wafers; and third, preventing liquid film deposited on one wafer from contacting another wafer during said rotation without reflecting said liquid film back onto said first wafer.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein said wafer is allowed to float so that it will rotate about an axis through its center and perpendicular to the plane of said wafer while it is rotating about said removed axis.
Claim 4
Dependent Claim
36 words
The method of claim 1 further comprising the step of rotating said wafer about an axis through its center and perpendicular to the plane of said wafer while said wafer is rotating about said removed axis.
Claim 5
Independent Claim
112 words
A method for coating a plurality of semiconductor wafers with a liquid film comprising: mounting said plurality of wafers proximate the perimeter of a disc sufficiently large to hold said wafers; depositing a continuous non-uniform layer of said liquid film on said wafers; rotating said disc about an axis through its center and perpendicular to the plane of said disc; preventing said liquid film deposited on each wafer from contacting any other of said wafers during said rotating without reflecting said liquid film back onto a wafer; and allowing each wafer to rotate about an axis through its center and perpendicular to the plane of said wafer while said disc is rotating.
Claim 6
Independent Claim
112 words
A method for coating a plurality of semiconductor wafers with a liquid film comprising: mounting said plurality of wafers proximate the perimeter of a disc sufficiently large to hold said wafers; depositing a continuous non-uniform layer of said liquid film on said wafers; rotating said disc about an axis through its center and perpendicular to the plane of said disc; preventing said liquid film deposited on each wafer from contacting any other of said wafers during said rotating without reflecting said liquid film back onto a wafer; and allowing each wafer to rotate about an axis through its center and perpendicular to the plane of said wafer while said disc is rotating.
Claim 7
Independent Claim
109 words
A method for coating a plurality of wafers with a liquid film comprising: mounting said plurality of wafers proximate the perimeter of a disc sufficiently large to hold said wafers; depositing a continuous non-uniform layer of said liquid film on said wafers; rotating said disc about an axis through its center and perpendicular to the plane of said disc; rotating each wafer about an axis through its center and perpendicular to the plane of said wafer while said disc is rotating; and preventing said liquid film deposited on each wafer from contacting any other of said wafers during said rotating without reflecting said liquid film back onto a wafer.
Claim 8
Independent Claim
109 words
A method for coating a plurality of wafers with a liquid film comprising: mounting said plurality of wafers proximate the perimeter of a disc sufficiently large to hold said wafers; depositing a continuous non-uniform layer of said liquid film on said wafers; rotating said disc about an axis through its center and perpendicular to the plane of said disc; rotating each wafer about an axis through its center and perpendicular to the plane of said wafer while said disc is rotating; and preventing said liquid film deposited on each wafer from contacting any other of said wafers during said rotating without reflecting said liquid film back onto a wafer.
Claim 9
Independent Claim
64 words
An apparatus for uniformly spreading a liquid film over a plurality of semiconductor wafers comprising: means for rotating the wafers about an axis perpendicular to the plane of the wafers and removed from the wafers; and baffle means located between each of said wafers and spaced from said wafers for preventing liquid film deposited on each wafer from contacting another wafer during said rotating.
Claim 10
Independent Claim
64 words
An apparatus for uniformly spreading a liquid film over a plurality of semiconductor wafers comprising: means for rotating the wafers about an axis perpendicular to the plane of the wafers and removed from the wafers; and baffle means located between each of said wafers and spaced from said wafers for preventing liquid film deposited on each wafer from contacting another wafer during said rotating.
Claim 11
Dependent Claim
42 words
The apparatus of claim 6 further comprising means for allowing each said wafer to float so that it will rotate about an axis through its center and perpendicular to the plane of said wafer while it is rotating about said removed axis.
Claim 12
Dependent Claim
36 words
The apparatus of claim 6 further comprising means for rotating each said wafer about an axis through its center and perpendicular to the plane of said wafer while said wafer is rotating about said removed axis.
Claim 13
Independent Claim
132 words
An apparatus for uniformly spreading a continuous non-uniform coating of a liquid film on a plurality of semiconductor wafers comprising: disc means, sufficiently large to hold said wafers, for supporting said wafers; means for mounting said plurality of wafers proximate the perimeter of said disc means; means for rotating said disc means about an axis through its center and perpendicular to the plane of said disc means; means for preventing said liquid film deposited on each wafer from contacting any other of said wafers while said disc means is rotating without reflecting said liquid film back into a wafer; and means for allowing each wafer to float so that it will rotate about an axis through its center and perpendicular to the plane of said wafer while said disc means is rotating.
Claim 14
Independent Claim
132 words
An apparatus for uniformly spreading a continuous non-uniform coating of a liquid film on a plurality of semiconductor wafers comprising: disc means, sufficiently large to hold said wafers, for supporting said wafers; means for mounting said plurality of wafers proximate the perimeter of said disc means; means for rotating said disc means about an axis through its center and perpendicular to the plane of said disc means; means for preventing said liquid film deposited on each wafer from contacting any other of said wafers while said disc means is rotating without reflecting said liquid film back into a wafer; and means for allowing each wafer to float so that it will rotate about an axis through its center and perpendicular to the plane of said wafer while said disc means is rotating.
Claim 15
Independent Claim
115 words
An apparatus for coating a plurality of semiconductor wafers comprising: disc means, sufficiently large to hold said wafers, for supporting said wafers; means for mounting said plurality of wafers proximate the perimeter of said disc means; means for rotating said disc means about an axis through its center and perpendicular to the plane of said disc means; means for rotating each wafer about an axis through its center and perpendicular to the plane of said wafer while said disc means is rotating; and means for preventing said liquid film deposited on each wafer from contacting any other of said wafers while said disc means is rotating without reflecting said liquid film back onto a wafer.
Claim 16
Independent Claim
115 words
An apparatus for coating a plurality of semiconductor wafers comprising: disc means, sufficiently large to hold said wafers, for supporting said wafers; means for mounting said plurality of wafers proximate the perimeter of said disc means; means for rotating said disc means about an axis through its center and perpendicular to the plane of said disc means; means for rotating each wafer about an axis through its center and perpendicular to the plane of said wafer while said disc means is rotating; and means for preventing said liquid film deposited on each wafer from contacting any other of said wafers while said disc means is rotating without reflecting said liquid film back onto a wafer.
Claim 17
Dependent Claim
38 words
The apparatus of claim 6 wherein said means for rotating comprises a disc, said wafers being mounted on said disc proximate the outer edge of said disc in a position elevated above a top surface of said disc.
Claim 18
Independent Claim
114 words
An apparatus for coating a plurality of semiconductor wafers with a uniform liquid film comprising: a disc having a flat top surface; a motor coupled to said disc for rotating said disc about its center; a plurality of platforms attached to said disc proximate the edge of said disc, each said platform being adapted to hold a wafer above said top surface of said disc, each said platform being rotatable about its center; and a plurality of elongated baffles mounted to said disc intermediate and spaced from said platforms, each of said baffles extending from a first point proximate the center of said disc to a second point proximate the edge of said disc.
Claim 19
Independent Claim
114 words
An apparatus for coating a plurality of semiconductor wafers with a uniform liquid film comprising: a disc having a flat top surface; a motor coupled to said disc for rotating said disc about its center; a plurality of platforms attached to said disc proximate the edge of said disc, each said platform being adapted to hold a wafer above said top surface of said disc, each said platform being rotatable about its center; and a plurality of elongated baffles mounted to said disc intermediate and spaced from said platforms, each of said baffles extending from a first point proximate the center of said disc to a second point proximate the edge of said disc.
References Cited (Backward Citations)
US3436259A
Cited
US3475867A
Cited
US3636492A
Cited
US3853091A
Cited
US4267212A
Cited
US4347302A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-02 | 1990-08-04 | 1991-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-02 | 1994-08-04 | 1995-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-02 | 1998-08-04 | 1999-02-03 | $7700.00 | Window Closed / Lapsed |