US3884698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for achieving uniform exposure in a photosensitive material on a semiconductor wafer
Assignee: HP Inc
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Filing: 1972-08-23
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Granted: 1975-05-20
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Expires: 1992-08-23
Abstract
Abstract A method of fabricating semiconductor devices on a wafer, in which an antireflection layer is interposed between a layer of insulating material and a photosensitive layer. The use of this antireflection layer allows suppression of the optical interference between an incident light wave and a light wave that is ordinarily reflected back into the photosensitive layer. Also, this layer provides a surface to which a positive photoresist material generally used as the photosensitive layer will adhere tenaciously.
Inventors
- 👤 Sanehiko Kakihama
- 👤 Edward B Stoneham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:24
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/091; H; H10; H10P; H10P95/00; Y; Y10; Y10S; Y10S430/00; Y10S430/135
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
93 words
A METHOD OF PREPARING A SUBSTRATE FOR TRANSFER OF A PATTERN TO SAID SUBSTRATE FROMA MASK IMPRINTED WITH AN PATTERN, SAID METHOD COMPRISING: DEPOSITING AN INSULATING LAYER OF ONE OR MORE SOLID INSULATING MATERIALS ONTO SAID SUBSTRATE, DEPOSITING AN ANTIREFLECTION LAYER OF ONE OR MORE SOLID MATERIALS ONTO SAID INSULATING LAYER; AND DEPOSITING A LAYER OF PHOTOSENSITIVE MATERIAL ONTO SAID ANTIREFLECTION LAYER, THE THICKNESS OF SAID ANTIREFLECTION LAYER AND THE THICKNESS OF SAID INSULATING LAYER BEING CHOSEN TO ACHIEVE CANCELLATION AMONG LIGHT WAVES REFLECTED BACK INTO SAID PHOTOSENSITIVE LAYER FROM THE OTHER LAYERS.
Claim 2
Independent Claim
93 words
A METHOD OF PREPARING A SUBSTRATE FOR TRANSFER OF A PATTERN TO SAID SUBSTRATE FROMA MASK IMPRINTED WITH AN PATTERN, SAID METHOD COMPRISING: DEPOSITING AN INSULATING LAYER OF ONE OR MORE SOLID INSULATING MATERIALS ONTO SAID SUBSTRATE, DEPOSITING AN ANTIREFLECTION LAYER OF ONE OR MORE SOLID MATERIALS ONTO SAID INSULATING LAYER; AND DEPOSITING A LAYER OF PHOTOSENSITIVE MATERIAL ONTO SAID ANTIREFLECTION LAYER, THE THICKNESS OF SAID ANTIREFLECTION LAYER AND THE THICKNESS OF SAID INSULATING LAYER BEING CHOSEN TO ACHIEVE CANCELLATION AMONG LIGHT WAVES REFLECTED BACK INTO SAID PHOTOSENSITIVE LAYER FROM THE OTHER LAYERS.
Claim 3
Dependent Claim
138 words
A method as in claim 1 wherein the thickness of said insulating layer is chosen so that in the photosensitive layer a first light wave reflected from the boundary between said substrate and said insulating layer will be 180 * out of phase with a second light wave reflected from said antireflection layer back into said layer of photosensitive material, and the thickness of said antireflection layer is chosen so that the fraction of light transmitted through it is such that in the photosensitive layer the amplitude of said first wave will be equal to the combined amplitudes of said second wave and a third wave reflected a second time from the substrate-insulator boundary after having been reflected once from the substrate-insulator boundary back to said antireflection layer and thence from said antireflection layer to the substrate-insulator boundary.
Claim 4
Dependent Claim
80 words
A method as in claim 1 wherein: the material comprising said substrate is one of the group consisting of silicon, germanium, gallium arsenide, tantalum nitride, molybdenum, and epitaxially grown germanium on gallium arsenide; the materials comprising said insulating layer are from the group consisting of silicon dioxide (SiO2), sputtered quartz, silicon nitride (Si3N4), aluminum oxide (Al2O3), silicon monoxide (SiO); and the materials comprising said antireflection layer are from the group consisting of molybdenum, chromium, gold, aluminum, nickel, or tantalum nitride.
References Cited (Backward Citations)
US3567506A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |