US4394673A
Expired / Lapsed
US
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Rare earth silicide Schottky barriers
Assignee: International Business Machines Corp
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Filing: 1980-09-29
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Granted: 1983-07-19
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Expires: 2000-09-29
Abstract
Abstract In the practice of this disclosure, rare earth disilicide low Schottky barriers ( APPROXLESS 0.4 eV) are used as low resistance contacts to n-Si. Further, high resistance contacts to p-Si (Schottky barrier of APPROXGREATER 0.7 eV) are also available by practice of this disclosure. A method is disclosed for forming contemporaneously high ( APPROXGREATER 0.8 eV) and low ( APPROXLESS 0.4 eV) energy Schottky barriers on an n-doped silicon substrate. Illustratively, the high energy Schottky barrier is formed by reacting platinum or iridium with silicon; the low energy Schottky barrier is formed by reacting a rare earth with silicon to form a disilicide. Illustratively, a double layer of Pt/on W is an effective diffusion barrier on Gd and prevents the Gd from oxidation.
Inventors
- 👤 Richard D. Thompson
- 👤 Boryeu Tsaur
- 👤 King-Ning Tu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:08
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/64; H10D64/01; H10D64/012; H10D64/0121
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
47 words
A disilicide Schottky barrier contact having a barrier potential of about 0.4 eV, comprising: an n-type silicon substrate; and a rare earth metal deposited on said n-type silicon substrate, wherein said disilicide Schottky barrier contact is formed by heating said silicon substrate and said rare earth metal.
Claim 2
Dependent Claim
47 words
A disilicide Schottky barrier contact having a barrier potential of about 0.4 eV, comprising: an n-type silicon substrate; and a rare earth metal deposited on said n-type silicon substrate, wherein said disilicide Schottky barrier contact is formed by heating said silicon substrate and said rare earth metal.
Claim 3
Dependent Claim
31 words
A disilicide Schottky barrier contact as set forth in claim 1 wherein said rare earth metal is a member of the group consisting of Ho, Gd, Er, Dy, Y and La.
Claim 4
Dependent Claim
23 words
A disilicide Schottky barrier contact as set forth in claim 2 wherein said heating is at approximately 400° C. for about 30 minutes.
Claim 5
Dependent Claim
22 words
A disilicide Schottky barrier contact as set forth in claim 3 including an oxidation barrier layer deposited on said rare earth metal.
Claim 6
Dependent Claim
39 words
A disilicide Schottky barrier contact as set forth in claim 4 wherein said oxidation barrier layer is one member of the group consisting of a transition metal Pt, Pd, Ni and refractory metals W, V, Cr, Mo and Ti.
Claim 7
Dependent Claim
47 words
A disilicide Schottky barrier contact having a barrier potential of about 0.7 eV, comprising: an p-type silicon substrate; and a rare earth metal deposited on said p-type silicon substrate, wherein said disilicide Schottky barrier contact is formed by heating said silicon substrate and said rare earth metal.
Claim 8
Dependent Claim
47 words
A disilicide Schottky barrier contact having a barrier potential of about 0.7 eV, comprising: an p-type silicon substrate; and a rare earth metal deposited on said p-type silicon substrate, wherein said disilicide Schottky barrier contact is formed by heating said silicon substrate and said rare earth metal.
Claim 9
Dependent Claim
31 words
A disilicide Schottky barrier contact as set forth in claim 6 wherein said rare earth metal is a member of the group consisting of Ho, Gd, Er, Dy, Y and La.
Claim 10
Dependent Claim
23 words
A disilicide Schottky barrier contact as set forth in claim 7 wherein said heating is at approximately 400° C. for about 30 minutes.
Claim 11
Dependent Claim
22 words
A disilicide Schottky barrier contact as set forth in claim 8 including an oxidation barrier layer deposited on said rare earth metal.
Claim 12
Dependent Claim
39 words
A disilicide Schottky barrier contact as set forth in claim 9 wherein said oxidation barrier layer is one member of the group consisting of a transition metal Pt, Pd, Ni and refractory metals W, V. Cr, Mo and Ti.
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) | 1986-07-18 | 1987-01-17 | 1987-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-18 | 1991-01-17 | 1991-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-18 | 1995-01-17 | 1995-07-19 | $7700.00 | Window Closed / Lapsed |