US3895147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fabrication mask using divalent rare earth element
Assignee: International Business Machines Corp
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Filing: 1971-12-27
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Granted: 1975-07-15
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Expires: 1991-12-27
Abstract
Abstract A mask for the manufacture of semiconductor and various small components. Rare earth elements capable of existing in the divalent state (Eu2 , Sm2 , Yb2 ) are combined with group VI elements (O, S, Se, Te) to provide the masking material. Trivalent rare earth elements, such as Eu3 , are also suitable if proper dopants are present. An example is Eu2O3 doped with Fe2O3. This masking material is harder than the components being manufactured and is opaque to the wavelength used in photoresist techniques while being transparent to visible wavelengths over broad thickness ranges. The mask can comprise a patterned layer on a substrate or patterned bulk crystals having regions of different thickness. Substrates such as soda-lime glass, sapphire, quartz, etc. are suitable. The masking material can be deposited as large area films having good uniformity and good optical properties. The material is readily etched but is not attacked by materials used in photoresist processing. Its reflectivity is very low, thereby providing easy alignment and good image definition during use.
Inventors
- 👤 Kie Y Ahn
- 👤 Frank P Laming
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:56
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; Y; Y10; Y10T; Y10T428/00; Y10T428/20; Y10T428/22; Y10T428/24; Y10T428/24479; Y10T428/24802
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
113 words
A MASK SUITABLE FOR USE IN THE FABRICATION OF COMPONENTS BY PROCESSES UTILIZING RADIIATION, COMPRISING: A SUPPORTING MEDIUM TRANSPARENT TO SAID RADIATION FOR SUPPORTING A MASKING MATERIAL THEREON, A MASKING MATERIAL LOCATED ON SAID SUPPORTING MEDIUM AND HAVING A GEOMETRIC PATERN USEFUL IN SAID FABRICATION PROCESS SAID PATTERN DEFINING FIRST AREAS OF SAID MASKING MATERIAL WHICH ARE TRANSPARENT TO SAID RADIATION AND SECOND AREAS OF SAID MASK WHICH ARE SUBSTANTIALLY OPAQUE TO SAID RADIATION WHEREIN SAID MASKING LAYER IS SUBSTANTIALLY COMPRISED OF A DIVALENT RARE EARTH ELEMENT SELECTED FROM THE GROUP CONSISTING OF SM2+ , EU2+, AND YB2+ COMBINED WITH AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF 0, S, SE AND TE.
Claim 2
Dependent Claim
113 words
A MASK SUITABLE FOR USE IN THE FABRICATION OF COMPONENTS BY PROCESSES UTILIZING RADIIATION, COMPRISING: A SUPPORTING MEDIUM TRANSPARENT TO SAID RADIATION FOR SUPPORTING A MASKING MATERIAL THEREON, A MASKING MATERIAL LOCATED ON SAID SUPPORTING MEDIUM AND HAVING A GEOMETRIC PATERN USEFUL IN SAID FABRICATION PROCESS SAID PATTERN DEFINING FIRST AREAS OF SAID MASKING MATERIAL WHICH ARE TRANSPARENT TO SAID RADIATION AND SECOND AREAS OF SAID MASK WHICH ARE SUBSTANTIALLY OPAQUE TO SAID RADIATION WHEREIN SAID MASKING LAYER IS SUBSTANTIALLY COMPRISED OF A DIVALENT RARE EARTH ELEMENT SELECTED FROM THE GROUP CONSISTING OF SM2+ , EU2+, AND YB2+ COMBINED WITH AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF 0, S, SE AND TE.
Claim 3
Dependent Claim
20 words
The mask of claim 1, where the thickness of said masking material is between about 1000 angstroms and 6000 angstroms.
Claim 4
Dependent Claim
17 words
The mask of claim 1, where the thickness of said masking material is greater than 6000 angstroms.
Claim 5
Dependent Claim
28 words
The mask of claim 1, where said masking material is a layer supported by said medium having holes etched in it which extend substantially to said supporting medium.
Claim 6
Dependent Claim
17 words
The mask of claim 1, wherein said masking material is buried in regions in said supporting medium.
Claim 7
Dependent Claim
108 words
A mask suitable for use in the fabrication of components by processes utilizing electromagnetic radiation, comprising: a supporting medium transparent to said radiation for supporting a masking material thereon, a masking material substantially opaque to said radiation located on said supporting medium and having a geometric pattern useful in said fabrication process, said pattern defining areas of said masking material which are transparent to said radiation, wherein said masking material consists of Eu3 combined with an element selected from the group consisting of O, S, Se and Te, said masking material further including Fe in an amount sufficient to make said masking material substantially opaque to said radiation.
Claim 8
Dependent Claim
108 words
A mask suitable for use in the fabrication of components by processes utilizing electromagnetic radiation, comprising: a supporting medium transparent to said radiation for supporting a masking material thereon, a masking material substantially opaque to said radiation located on said supporting medium and having a geometric pattern useful in said fabrication process, said pattern defining areas of said masking material which are transparent to said radiation, wherein said masking material consists of Eu3 combined with an element selected from the group consisting of O, S, Se and Te, said masking material further including Fe in an amount sufficient to make said masking material substantially opaque to said radiation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |