US4267259A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exposure process
Assignee: International Business Machines Corp
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Filing: 1979-02-16
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Granted: 1981-05-12
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Expires: 1999-02-16
Abstract
Abstract Radiation sensitive layers are x-ray exposed by providing a metal mask pattern on the layer through which the layer is exposed. The metal mask pattern is formed by applying a blanket metal layer to the radiation sensitive layer followed by an electron beam sensitive resist layer which is patterned by an electron beam exposure process. The exposed portions of the metal layer are then etched away to form the metal mask pattern.
Inventors
- 👤 Harald Bohlen
- 👤 Johann Greschner
- 👤 Werner Kulcke
- 👤 Peter Nehmiz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:14
CPC Classifications
H; H10; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2045; G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/095; H10P76/2047; Y; Y10; Y10S; Y10S430/00; Y10S430/167; Y10S430/168
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
191 words
A process for x-ray exposing a radiation sensitive layer comprising the following steps: (a) applying a first, x-ray sensitive layer to a semiconductor wafer, used for the manufacture of a plurality of integrated circuits, on which are provided alignment marks between the individual surface areas destined to accomodate said integrated circuits, (b) applying a second, superimposed x-ray absorbing metal layer only to the individual surface areas destined to accomodate said integrated circuits, (c) applying a third, superimposed electron beam sensitive layer, (d) removing the areas of the x-ray sensitive layer and the electron beam sensitive layer over the alignment marks by exposure and development to bare the alignment marks, (e) electron beam exposing the third layer in the form of a pattern defining the areas of the first layer which are to be x-ray exposed after alignment of the individual surface areas using electron beams and said alignment masks, (f) removing the exposed areas of the third layer by development, (g) removing the bared areas of the second layer by etching, and (h) exposing the first layer to x-rays through the opening in the second layer which serves as a mask.
Claim 2
Dependent Claim
191 words
A process for x-ray exposing a radiation sensitive layer comprising the following steps: (a) applying a first, x-ray sensitive layer to a semiconductor wafer, used for the manufacture of a plurality of integrated circuits, on which are provided alignment marks between the individual surface areas destined to accomodate said integrated circuits, (b) applying a second, superimposed x-ray absorbing metal layer only to the individual surface areas destined to accomodate said integrated circuits, (c) applying a third, superimposed electron beam sensitive layer, (d) removing the areas of the x-ray sensitive layer and the electron beam sensitive layer over the alignment marks by exposure and development to bare the alignment marks, (e) electron beam exposing the third layer in the form of a pattern defining the areas of the first layer which are to be x-ray exposed after alignment of the individual surface areas using electron beams and said alignment masks, (f) removing the exposed areas of the third layer by development, (g) removing the bared areas of the second layer by etching, and (h) exposing the first layer to x-rays through the opening in the second layer which serves as a mask.
Claim 3
Dependent Claim
17 words
The process in accordance with claim 1, in which the x-ray absorbing layer is a heavy-metal layer.
Claim 4
Dependent Claim
23 words
The process in accordance with claim 1 in which the first, x-ray sensitive layer is a 1 to 10 μm thick photoresist layer.
Claim 5
Dependent Claim
19 words
The process in accordance with claim 1 in which the x-ray absorbing layer is 0.1 to 0.5 μm thick.
Claim 6
Dependent Claim
23 words
The process in accordance with claim 1 in which the third, x-ray sensitive layer is a 0.1 to 0.5 μm thick photoresist layer.
Claim 7
Dependent Claim
21 words
The process in accordance with claim 1 in which the third, electron beam sensitive layer is removed prior to x-ray exposure.
Claim 8
Dependent Claim
29 words
The process in accordance with claim 1 in which the first and third layers are applied by spinning, with the deviations from the nominal thickness being less than ±10%.
Claim 9
Dependent Claim
21 words
The process in accordance with claim 1 in which the x-ray absorbing layer is applied by vapor deposition through a mask.
Claim 10
Dependent Claim
27 words
The process in accordance with claim 1 in which exposure of the electron beam sensitive layer is effected by means of a computer-controlled electron beam line recorder.
Claim 11
Dependent Claim
43 words
The process in accordance with claim 9 in which exposure of the electron beam sensitive layer is effected at low beam acceleration voltages of 1 to 10 KV, the electron beams not penetrating or penetrating only a small part of the second layer.
References Cited (Backward Citations)
US3849136A
Cited
US4165395A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-11 | 1984-11-10 | 1985-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-11 | 1988-11-10 | 1989-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-11 | 1992-11-10 | 1993-05-12 | $7700.00 | Window Closed / Lapsed |