US3661436A
Expired / Lapsed
US
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Transparent fabrication masks utilizing masking material selected from the group consisting of spinels, perovskites, garnets, fluorides and oxy-fluorides
Assignee: International Business Machines Corp
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Filing: 1970-06-30
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Granted: 1972-05-09
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Expires: 1990-06-30
Abstract
Abstract A mask for the manufacture of semiconductor and other very small components. The mask is comprised of patterns of multi-component oxides and fluorides, such as spinels, perovskites, and garnets. In general, the materials are harder than the components being manufactured and are opaque to the wavelength used in photoresist techniques, while being transparent to the visible wavelengths. Materials with an energy gap between approximately 2.8 eV and 5 eV satisfy these optical properties, a particular example being GaFeO3. These masks are not damaged by surface defects on the components and can be visually aligned.
Inventors
- 👤 Ronald S Horwath
- 👤 Varadachari Sadagopan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:22
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/943; Y10S438/945
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
19 words
The mask of claim 1 wherein said masking material has a thickness between approximately 500 angstroms and 3 microns.
Claim 2
Dependent Claim
29 words
The mask of claim 1, where said masking material is a layer supported by said medium, said layer having holes etched in it which extend substantially to said medium.
Claim 3
Dependent Claim
16 words
The mask of claim 1 wherein said masking material is buried in regions in said medium.
Claim 4
Dependent Claim
88 words
A mask suitable for use in device manufacturing processes wherein ultraviolet radiation is used, said mask being a medium which is continuous and pin hole free and having first regions of lesser thickness which are opaque to said radiation and transparent to visible light and second regions which are of greater thickness and are opaque to visible light and to said radiation, said first and second regions defining a geometric pattern, and wherein said masking medium is chosen from the group consisting of spinels, perovskites, fluorides, and oxy-fluorides.
Claim 5
Dependent Claim
11 words
The mask of claim 5, where the masking material is GaFeO3.
Claim 6
Dependent Claim
88 words
A mask for use in the production of components by photoresist techniques wherein ultraviolet radiation is used to expose said photoresist comprising: a first medium which is transparent to said radiation and to visible wavelengths; a second medium opaque to said ultraviolet radiation and transparent to said visible wavelengths formed in a pattern on said first medium, said second medium being continuous and pin hole free and defining the desired mask pattern, said second medium being chosen from the group consisting of spinels, perovskites, garnets, fluorides, and oxy-fluorides.
Claim 7
Dependent Claim
26 words
The mask of claim 4, wherein said second medium is a layer on said first medium having apertures therein, said apertured layer defining said mask pattern.
Claim 8
Dependent Claim
23 words
The mask of claim 4, wherein said second medium is located in regions of said first medium, said regions defining said masked pattern.
Claim 9
Dependent Claim
17 words
The mask of claim 4, wherein said second medium is 500 angstroms to 3 microns in thickness.
Claim 10
Dependent Claim
56 words
A mask used in device fabrication processes, comprising: a first medium which is transparent to both visible and ultraviolet radiation; a second medium on said first medium, said second medium comprising continuous, pin hole free regions of GaFeO3, said GaFeO3 regions forming the desired mask pattern and having a thickness between 500 angstroms and 3 microns.
Claim 11
Dependent Claim
28 words
A mask of claim 11, wherein said regions are located in portions of said first medium and are transparent to visible radiation while being opaque to ultra-violet radiation.
Claim 12
Dependent Claim
31 words
A mask of claim 11, wherein said regions are portions of a continuous film of GaFeO3 having apertures therein, said GaFeO3 being opaque to ultra-violet light and transparent to visible radiation.
Claim 13
Dependent Claim
80 words
A mask suitable for use in the fabrication of components by processes utilizing radiation, comprising: a medium transparent to said radiation and to visible light, a masking material located on said supporting medium, said masking material being continuous and pinhole free and having a geometric pattern useful in said fabrication process, said masking material having an energy gap between 8eV and 5.0eV and being selected from the group consisting of spinels, perovskites, garnets, rare earth fluorides, and rare earth oxy-fluorides.
Claim 14
Dependent Claim
76 words
A mask suitable for use in the fabrication of components by processes utilizing radiation, comprising: a medium transparent to said radiation and to visible light; a masking material located on said supporting medium, said masking material being continuous and pinhole free and having a geometric pattern useful in said fabrication process, said masking material being comprised of GaFeO3 having an energy gap between 2.8eV and 5.0eV and a thickness between approximately 500 angstroms and 3 microns.
Claim 15
Dependent Claim
92 words
A mask for use in the production of components by photoresist techniques wherein radiation is used to expose said photoresist, comprising: a first medium which is transparent to said radiation and to visible wavelengths; a second medium formed in a pattern on said first medium, said second medium being continuous and pin hole free and defining the desired mask pattern, where said second medium is chosen from the group consisting of spinels, perovskites, fluorides, and oxy-fluorides, said materials being selected from the group consisting of GaFeO3, MgFe2O4, YIG, LaF3, CeF3, and LaOF.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |