US4937162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of obtaining relatively aligned patterns on two opposite surfaces of an opaque slice
Assignee: US Philips Corp
•
Filing: 1988-12-12
•
Granted: 1990-06-26
•
Expires: 2008-12-12
Abstract
Abstract The invention relates to a method of obtaining relatively aligned patterns on two opposite surfaces of an opaque slice (2). This can be realized in that the opaque slice (2) carrying a reference pattern (3) is glued on a transparent plate (1) on the side of the said pattern (3) and an alignment pattern (8) aligned with respect to the reference pattern (3) is transferred by photolithography to the plate (1). This alignment pattern (8) is used to form on the other surface of the opaque slice (2) the desired patterns (9) aligned with respect to the alignment pattern (8).
Inventors
- 👤 Pierre Goirand
- 👤 Jacques Schneider
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:13
CPC Classifications
G; G03; G03F; G03F9/00; G03F9/70; G03F7/00; G03F7/20; G03F7/2022
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
220 words
A method of obtaining relatively aligned patterns on first and second opposite surfaces of an opaque slice having on the first surface at least one reference pattern, characterized in that (a) joining the first surface of the opaque slice to a first surface of the transparent plate having larger dimensions than the opaque slice; (b) providing a photoresist layer on the second surface of the slice and on the part of the first surface of the transparent plate, which projects from the outline of the opaque slice; (c) aligning an alignment mask with respect to the reference pattern; (d) exposing through the alignment mask and the second surface of the transparent plate opposite to its first surface so as to generate an alignment pattern on the photoresist projecting from the outline of the opaque slice; (e) developing the photoresist exposed during the step (d) so as to cause the alignment pattern to appear; (f) aligning a realignment mask arranged opposite to the second surface of the slice with the said alignment pattern; (g) exposing through the realignment mask so as to generate on the photoresist covering the second surface of the slice a functional pattern aligned with respect to the alignment pattern; (h) developing the photoresist exposed during the step (g) so as to cause the functional pattern to appear.
Claim 2
Independent Claim
220 words
A method of obtaining relatively aligned patterns on first and second opposite surfaces of an opaque slice having on the first surface at least one reference pattern, characterized in that (a) joining the first surface of the opaque slice to a first surface of the transparent plate having larger dimensions than the opaque slice; (b) providing a photoresist layer on the second surface of the slice and on the part of the first surface of the transparent plate, which projects from the outline of the opaque slice; (c) aligning an alignment mask with respect to the reference pattern; (d) exposing through the alignment mask and the second surface of the transparent plate opposite to its first surface so as to generate an alignment pattern on the photoresist projecting from the outline of the opaque slice; (e) developing the photoresist exposed during the step (d) so as to cause the alignment pattern to appear; (f) aligning a realignment mask arranged opposite to the second surface of the slice with the said alignment pattern; (g) exposing through the realignment mask so as to generate on the photoresist covering the second surface of the slice a functional pattern aligned with respect to the alignment pattern; (h) developing the photoresist exposed during the step (g) so as to cause the functional pattern to appear.
Claim 3
Dependent Claim
18 words
A method as claimed in claim 1, characterized in that the opaque slice (2) is a semiconductor crystal.
Claim 4
Independent Claim
22 words
A method as claimed in any one of claims 1 and 2, characterized in that the transparent plate (1) consists of glass.
Claim 5
Dependent Claim
30 words
A method as claimed in claim 3, characterized in that the opaque slice (2) and the transparent plate are joined together by means of a layer (4) of transparent wax.
Claim 6
Dependent Claim
28 words
A method as claimed in claim 4, characterized in that the steps of alignment and exposure are carried out by means of a single-face apparatus operating in projection.
Claim 7
Dependent Claim
28 words
A method as claimed in claim 4, characterized in that the alignment pattern (8) is symmetrical, and in that the alignment mask and the realignment mask are identical.
References Cited (Backward Citations)
DE1060717B
Cited
US3963489A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-25 | 1993-12-25 | 1994-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-25 | 1997-12-25 | 1998-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-25 | 2001-12-25 | 2002-06-26 | $7700.00 | Window Closed / Lapsed |