US4170818A
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Barrier height voltage reference
Assignee: HP Inc
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Filing: 1977-10-03
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Granted: 1979-10-16
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Expires: 1997-10-03
Abstract
Abstract A barrier height voltage reference includes two field-effect transistors which are substantially identical except for their gate-to-channel potential barrier characteristics and which are biased to carry equal drain currents at equal drain voltages. The resulting difference in potential between the gate contacts of the two field effect transistors produces a voltage reference which is substantially independent of operating point, supply potential, and temperature.
Inventors
- 👤 Morley C. Tobey, Jr.
- 👤 David J. Giuliani
- 👤 Peter B. Ashkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:57
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/24; G05F3/242; G05F3/247; G05F3/245; H; H10; H10D; H10D30/00; H10D30/60; H10D30/67; H10D30/6729; H10D30/6737; H10D30/6738; H10D30/674; H10D30/675; H10D62/00; H10D62/80; H10D62/85; H10D62/86; H10D62/8603; H10D62/874; H10D64/00; H10D64/60; H10D64/602; H10D64/64; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0135; H10D84/014; H10D84/02; H10D84/03; H10D84/038; H10D84/80; H10D84/86; H10D84/87
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
255 words
A method of fabricating a voltage reference comprising the steps of: growing an epitaxial layer on a substrate material having higher resistivity than that of the epitaxial layer; growing a field oxide layer on the epitaxial layer; opening a first isolation diffusion window, a second isolation diffusion window and a third isolation diffusion window in the field oxide layer; forming isolation diffusions in the low resistivity epitaxial layer within each of the first, second and third isolation diffusion windows; etching a first source window, a first drain window, a second source window and a second drain window in the field oxide layer; forming source diffusions in the epitaxial layer within the first and second source windows and drain diffusions in the epitaxial layer within the first and second drain windows; etching a first gate window in the field oxide layer; etching a first source contact window, a first drain contact window, a second source contact window and a second drain contact window in the field oxide layer; depositing a first metal on the epitaxial layer through the first gate window, the first source contact window, the first drain contact window, the second source contact window and the second drain contact window; etching a second gate window in the field oxide layer; and depositing a second metal through the first gate window, the first source contact window, the first drain contact window, the second source contact window, the second drain contact window and the second gate window, the second metal being different from said first metal.
Claim 2
Independent Claim
255 words
A method of fabricating a voltage reference comprising the steps of: growing an epitaxial layer on a substrate material having higher resistivity than that of the epitaxial layer; growing a field oxide layer on the epitaxial layer; opening a first isolation diffusion window, a second isolation diffusion window and a third isolation diffusion window in the field oxide layer; forming isolation diffusions in the low resistivity epitaxial layer within each of the first, second and third isolation diffusion windows; etching a first source window, a first drain window, a second source window and a second drain window in the field oxide layer; forming source diffusions in the epitaxial layer within the first and second source windows and drain diffusions in the epitaxial layer within the first and second drain windows; etching a first gate window in the field oxide layer; etching a first source contact window, a first drain contact window, a second source contact window and a second drain contact window in the field oxide layer; depositing a first metal on the epitaxial layer through the first gate window, the first source contact window, the first drain contact window, the second source contact window and the second drain contact window; etching a second gate window in the field oxide layer; and depositing a second metal through the first gate window, the first source contact window, the first drain contact window, the second source contact window, the second drain contact window and the second gate window, the second metal being different from said first metal.
Claim 3
Dependent Claim
40 words
A method as in claim 1 comprising the additional step after the step of forming source and drain diffusions in the epitaxial layer of separating the semiconductor substrate into two parts, each part having one source and one drain diffusion.
Claim 4
Dependent Claim
63 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type AlAs and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and Pt, the first and second metals being different.
Claim 5
Dependent Claim
67 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type CdS and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Pt, Au, Pd, Cu, Ag, and Ni, the first and second metals being different.
Claim 6
Dependent Claim
65 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type CdSe and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Pt, Au, Ag, and Cu, the first and second metals being different.
Claim 7
Dependent Claim
65 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type CdTe and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pt, Ag, and Al, the first and second metals being different.
Claim 8
Dependent Claim
67 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type GaAs and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pt, Be, Ag, Cu, and Al, the first and second metals being different.
Claim 9
Dependent Claim
63 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on p-type GaAs and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and Al, the first and second metals being different.
Claim 10
Dependent Claim
67 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type GaP and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Cu, Al, Au, Pt, Mg and Ag, the first and second metals being different.
Claim 11
Dependent Claim
63 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type Ge and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and Al, the first and second metals being different.
Claim 12
Dependent Claim
63 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type InP and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and Ag, the first and second metals being different.
Claim 13
Dependent Claim
66 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type PbO and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Ag, Bi, Ni, Pb, and In, the first and second metals being different.
Claim 14
Dependent Claim
65 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type Si and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Mo, PtSi and W the first and second metals being different.
Claim 15
Dependent Claim
63 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on p-type Si and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and PtSi, the first and second metals being different.
Claim 16
Dependent Claim
63 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type SiC and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and Al the first and second metals being different.
Claim 17
Dependent Claim
64 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type SnO2 and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Ag and Cu, the first and second metals being different.
Claim 18
Dependent Claim
65 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type ZnO and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pt, Pd, and Ag, the first and second metals being different.
Claim 19
Dependent Claim
70 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type ZnS and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pd, Pt, Cu, Ag, In, Al, Ti, and Mg, the first and second metals being different.
Claim 20
Dependent Claim
65 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type ZnSe and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pt, Cu, and Mg the first and second metals being different.
Claim 21
Dependent Claim
67 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on n-type ZnO and the step of depositing a first metal comprises the step of depositing a metal selected from the group consisting of In and Ti and the step of depositing a second metal comprises the step of depositing Cu.
Claim 22
Dependent Claim
73 words
A method as in claim 1 wherein the step of growing an epitaxial layer on a substrate material comprises the step of growing an epitaxial layer on a substrate material selected from the group consisting of n-type AlAs, n-type CdS, n-type CdSe, n-type CdTe, n-type GaAs, p-type GaAs, n-type GaP, n-type Ge, n-type InP, n-type PbO, n-type Si, p-type Si, n-type SiC, n-type SnO 2 , n-type ZnO, n-type ZnS, and n-type ZnSe.
Claim 23
Independent Claim
266 words
A method of fabricating a voltage reference comprising the steps of: growing an epitaxial layer on a first substrate material having higher resistivity than that of the epitaxial layer; growing a field oxide layer on the epitaxial layer; opening an isolation diffusion window in the field oxide layer; forming isolation diffusion in the epitaxial layer within the isolation diffusion window; etching source and drain windows in the field oxide layer; forming source and drain diffusions in the epitaxial layer within the source and drain windows; etching a source contact window, a drain contact window and a gate window in the field oxide layer; depositing a first metal through the etched source contact window, the etched drain contact window and the etched gate window; growing a second epitaxial layer which is substantially identical to the first epitaxial layer on a second substrate material; growing a second field oxide layer on the second epitaxial layer; opening a second isolation diffusion window in the second field oxide layer; forming isolation diffusions in the second epitaxial layer within the second isolation diffusion window; etching a second source window and a second drain window in the second field oxide layer; forming source and drain diffusions in the second epitaxial layer within the second source window and the second drain window; etching a second source contact window, a second drain contact window and a second gate window in the second field oxide layer; and depositing a second metal through the etched second source contact window, second drain contact window and second gate window, the second metal being different from the first metal.
Claim 24
Independent Claim
266 words
A method of fabricating a voltage reference comprising the steps of: growing an epitaxial layer on a first substrate material having higher resistivity than that of the epitaxial layer; growing a field oxide layer on the epitaxial layer; opening an isolation diffusion window in the field oxide layer; forming isolation diffusion in the epitaxial layer within the isolation diffusion window; etching source and drain windows in the field oxide layer; forming source and drain diffusions in the epitaxial layer within the source and drain windows; etching a source contact window, a drain contact window and a gate window in the field oxide layer; depositing a first metal through the etched source contact window, the etched drain contact window and the etched gate window; growing a second epitaxial layer which is substantially identical to the first epitaxial layer on a second substrate material; growing a second field oxide layer on the second epitaxial layer; opening a second isolation diffusion window in the second field oxide layer; forming isolation diffusions in the second epitaxial layer within the second isolation diffusion window; etching a second source window and a second drain window in the second field oxide layer; forming source and drain diffusions in the second epitaxial layer within the second source window and the second drain window; etching a second source contact window, a second drain contact window and a second gate window in the second field oxide layer; and depositing a second metal through the etched second source contact window, second drain contact window and second gate window, the second metal being different from the first metal.
Claim 25
Dependent Claim
87 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type AlAs; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type AlAs; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and Pt, the first and second metals being different.
Claim 26
Dependent Claim
91 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type CdS; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type CdS; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Pt, Au, Pd, Cu, Ag and Ni, the first and second metals being different.
Claim 27
Dependent Claim
89 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type CdSe; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type CdSe; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Pt, Au, Ag and Cu, the first and second metals being different.
Claim 28
Dependent Claim
89 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type CdTe; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type CdTe; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pt, Ag and Al, the first and second metals being different.
Claim 29
Dependent Claim
91 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type GaAs; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type GaAs; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pt, Be, Ag, Cu and Al, the first and second metals being different.
Claim 30
Dependent Claim
87 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on p-type GaAs; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on p-type GaAs; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and Al, the first and second metals being different.
Claim 31
Dependent Claim
91 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type GaP; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type GaP; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Cu, Al, Au, Pt, Mg, and Ag, the first and second metals being different.
Claim 32
Dependent Claim
87 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type Ge; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type Ge; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and Al, the first and second metals being different.
Claim 33
Dependent Claim
87 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type InP; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type InP; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and Ag the first and second metals being different.
Claim 34
Dependent Claim
91 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type PbO; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type PbO; and the steps of depositing the first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Ag, Bi, Ni, Pb, and In, the first and second metals being different.
Claim 35
Dependent Claim
89 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type Si; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type Si; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Mo, PtSi and W, the first and second metals being different.
Claim 36
Dependent Claim
87 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on p-type Si; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on p-type Si; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and PtSi, the first and second metals being different.
Claim 37
Dependent Claim
87 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type SiC; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type SiC; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au and A1, the first and second metals being different.
Claim 38
Dependent Claim
88 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type SnO2; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type SnO2; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Ag and Cu, the first and second metals being different.
Claim 39
Dependent Claim
89 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type ZnO; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type ZnO; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pt, Pd and Ag, the first and second metals being different.
Claim 40
Dependent Claim
94 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type ZnS; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type ZnS; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pd, Pt, Cu, Ag, In, Al, Ti, and Mg, the first and second metals being different.
Claim 41
Dependent Claim
89 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type ZnSe; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type ZnSe; and the steps of depositing first and second metals comprise the steps of depositing first and second metals selected from the group consisting of Au, Pt, Cu and Mg, the first and second metals being different.
Claim 42
Dependent Claim
74 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on a substrate material selected from the group consisting of n-type AlAs, n-type CdS, n-type CdSe, n-type CdTe, n-type GaAs, p-type GaAs, n-type GaP, n-type Ge, n-type InP, n-type PbO, n-type Si, p-type Si, n-type SiC, n-type SnO 2 , n-type ZnO, n-type ZnS, and n-type ZnSe.
Claim 43
Dependent Claim
142 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on a substrate material selected from the group consisting of n-type AlAs, n-type CdS, n-type CdSe, n-type CdTe, n-type GaAs, p-type GaAs, n-type GaP, n-type Ge, n-type InP, n-type PbO, n-type Si, p-type Si, n-type SiC, n-type SnO 2 , n-type ZnO, n-type ZnS, and n-type ZnSe; and the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on a substrate material selected from the group consisting of n-type AlAs, n-type CdS, n-type CdSe, n-type CdTe, n-type GaAs, p-type GaAs, n-type GaP, n-type Ge, n-type InP, n-type PbO, n-type Si, p-type Si, n-type SiC, n-type SnO 2 , n-type ZnO, n-type ZnS, and n-type ZnSe.
Claim 44
Dependent Claim
91 words
A method as in claim 22 wherein the step of growing an epitaxial layer on a first substrate material comprises the step of growing an epitaxial layer on n-type ZnO; the step of growing an epitaxial layer on a second substrate material comprises the step of growing an epitaxial layer on n-type ZnO; the step of depositing a first metal comprises the step of depositing a metal selected from the group consisting of In and Ti; and the step of depositing a second metal consists of the step of depositing Cu.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1982-10-15 | 1983-04-16 | 1983-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-15 | 1987-04-16 | 1987-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-15 | 1991-04-16 | 1991-10-16 | $7700.00 | Window Closed / Lapsed |