Patent US4908686A successfully refreshed from Google Patents.
US4908686A
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Stacked silicide/silicon mid- to long-wavelength infrared detector
Assignee: California Institute of Technology
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Filing: 1988-08-01
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Granted: 1990-03-13
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Expires: 2008-08-01
Abstract
Abstract The use of stacked Schottky barriers (16) with epitaxially grown thin silicides (10) combined with selective doping (22) of the barriers provides high quantum efficiency infrared detectors (30) at longer wavelengths that is compatible with existing silicon VLSI technology.
Inventors
- 👤 Joseph Maserjian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:42
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/227; H10F39/00; H10F39/10; H10F39/12; H10F39/18; H10F39/184; H10F39/1843
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
74 words
An improved infrared detector comprising at least one unit comprising a thin single crystal metal silicide layer sandwiched between two single crystal silicon layers, each doped to a first doping level, each said silicon layer forming an interface with said silicide layer, the improvement comprising that portion of each said silicon layer adjacent said interface having a second doping level higher than that of said first doping level, thereby forming a reduced Schottky barrier.
Claim 2
Dependent Claim
74 words
An improved infrared detector comprising at least one unit comprising a thin single crystal metal silicide layer sandwiched between two single crystal silicon layers, each doped to a first doping level, each said silicon layer forming an interface with said silicide layer, the improvement comprising that portion of each said silicon layer adjacent said interface having a second doping level higher than that of said first doping level, thereby forming a reduced Schottky barrier.
Claim 3
Dependent Claim
33 words
The detector of claim 1 wherein said metal silicide layer is selected from the group of metal silicides that may be epitaxially grown on silicon, thereby forming a heteroepitaxial interface with said silicon.
Claim 4
Dependent Claim
16 words
The detector of claim 2 comprising a plurality of said units to form repeated Schottky barriers.
Claim 5
Dependent Claim
22 words
The detector of claim 2 wherein said metal silicide is selected from the group consisting of CoSi 2 and NiSi 2 .
Claim 6
Dependent Claim
18 words
The detector of claim 1 wherein said metal silicide has a thickness ranging up to about 10 nm.
Claim 7
Dependent Claim
78 words
An improved infrared detector comprising a plurality of stacked metal silicide layers, each silicide layer sandwiched between two silicon layers, each doped to a first doping level, each said silicon layer forming an interface with an adjacent metal silicide layer to form repeated p-type Schottky barriers, the improvement comprising that portion of each said silicon layer adjacent said interface having a doping level higher than that of said first doping level, thereby providing a reduced effective barrier height.
Claim 8
Dependent Claim
78 words
An improved infrared detector comprising a plurality of stacked metal silicide layers, each silicide layer sandwiched between two silicon layers, each doped to a first doping level, each said silicon layer forming an interface with an adjacent metal silicide layer to form repeated p-type Schottky barriers, the improvement comprising that portion of each said silicon layer adjacent said interface having a doping level higher than that of said first doping level, thereby providing a reduced effective barrier height.
Claim 9
Dependent Claim
25 words
The detector of claim 6 wherein said metal silicide is selected from the group consisting of metal silicides that may be epitaxially grown on silicon.
Claim 10
Dependent Claim
37 words
The detector of claim 7 wherein lateral contacts are provided to a plurality of layers by providing common n + contacting regions to the metal silicides and common p + contacting regions to the interleafing p-silicon layers.
Claim 11
Dependent Claim
22 words
The detector of claim 8 wherein said metal silicide is selected from the group consisting of CoSi 2 and NiSi 2 .
Claim 12
Dependent Claim
18 words
The detector of claim 7 wherein said metal silicide has a thickness ranging up to about 10 nm.
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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) | 1993-03-12 | 1993-09-11 | 1994-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-12 | 1997-09-11 | 1998-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-12 | 2001-09-11 | 2002-03-13 | $7700.00 | Window Closed / Lapsed |