US4183035A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inverted heterojunction photodiode
Assignee: Boeing North American Inc
•
Filing: 1978-06-26
•
Granted: 1980-01-08
•
Expires: 1998-06-26
Abstract
Abstract A low-leakage, heterojunction photodiode for use as a detector sensitive to infrared radiation is provided. The diode structure comprises a PbTe substrate of n-type conductivity with an n-type epitaxial buffer layer on the substrate and an epitaxial active layer on the buffer layer. The buffer layer is either Pb(1-x)SxTe or Pb1-xSexTe with the atomic fraction of S or Se, x, being greater than 0 but less than 0.1. The active layer is Pb1-ySnyTe with the atomic fraction of Sn, y, being greater than 0 but less than 0.3. There is a p-n junction created in the active layer with the n side of the junction being adjacent the buffer layer. Metal is deposited on the substrate and on the active layer to provide electrical contact to the diode.
Inventors
- 👤 Cheng-Chi Wang
- 👤 John G. Pasko
- 👤 Joseph T. Longo
- 👤 John E. Clarke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:00
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/40; H04B10/43; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/222; H10F30/24; H10F39/00; H10F39/10; H10F39/12; H10F39/18; H10F39/184; H10F77/00; H10F77/10; H10F77/12; H10F77/127; Y; Y10; Y10S; Y10S438/00; Y10S438/912
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
138 words
A semiconducting device comprising: a substrate comprising a PbTe crystal of n-type conductivity; an epitaxial buffer layer of Pb.sub.(1-x) X x Te of n-type conductivity on said substrate, wherein X is a Group VI element selected from the group consisting of S and Se and wherein x is a value greater than 0 but less than 0.1; an epitaxial active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wherein y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and electrical contact means coupled to said substrate and to said active layer.
Claim 2
Dependent Claim
138 words
A semiconducting device comprising: a substrate comprising a PbTe crystal of n-type conductivity; an epitaxial buffer layer of Pb.sub.(1-x) X x Te of n-type conductivity on said substrate, wherein X is a Group VI element selected from the group consisting of S and Se and wherein x is a value greater than 0 but less than 0.1; an epitaxial active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wherein y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and electrical contact means coupled to said substrate and to said active layer.
Claim 3
Dependent Claim
149 words
A focal plane comprising: a plurality of mesa photodiodes on a PbTe substrate of n-type conductivity, and wherein each of said mesa diodes comprises: an epitaxial buffer layer of Pb.sub.(1-x) X x Te of n-type conductivity on said substrate, wherein X is a Group VI element selected from the group consisting of S and Se and wherein x is a value greater than 0 but less than 0.1; an epitaxial active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wheren y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and electrical contact means coupled to said substrate and to said active layer.
Claim 4
Dependent Claim
149 words
A focal plane comprising: a plurality of mesa photodiodes on a PbTe substrate of n-type conductivity, and wherein each of said mesa diodes comprises: an epitaxial buffer layer of Pb.sub.(1-x) X x Te of n-type conductivity on said substrate, wherein X is a Group VI element selected from the group consisting of S and Se and wherein x is a value greater than 0 but less than 0.1; an epitaxial active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wheren y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and electrical contact means coupled to said substrate and to said active layer.
Claim 5
Dependent Claim
120 words
A photodiode comprising: a substrate comprising a PbTe crystal of n-type conductivity; an epitaxial buffer layer of Pb.sub.(1-x) S x Te of n-type conductivity on said substrate, wherein x is a value greater than 0 but less than 0.1; an epitaxial active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wherein y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and electrical contact means coupled to said substrate and to said active layer.
Claim 6
Dependent Claim
120 words
A photodiode comprising: a substrate comprising a PbTe crystal of n-type conductivity; an epitaxial buffer layer of Pb.sub.(1-x) S x Te of n-type conductivity on said substrate, wherein x is a value greater than 0 but less than 0.1; an epitaxial active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wherein y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and electrical contact means coupled to said substrate and to said active layer.
Claim 7
Dependent Claim
120 words
A photodiode comprising: a substrate comprising a PbTe crystal of n-type conductivity; an epitaxial buffer layer of Pb.sub.(1-x) Se x Te on n-type conductivity on said substrate, wherein x is a value greater than 0 but less than 0.1; an epitaxial active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wherein y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and electrical contact means coupled to said substrate and to said active layer.
Claim 8
Dependent Claim
120 words
A photodiode comprising: a substrate comprising a PbTe crystal of n-type conductivity; an epitaxial buffer layer of Pb.sub.(1-x) Se x Te on n-type conductivity on said substrate, wherein x is a value greater than 0 but less than 0.1; an epitaxial active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wherein y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and electrical contact means coupled to said substrate and to said active layer.
Claim 9
Independent Claim
165 words
A method of fabricating a semiconducting device comprising the steps of: providing a substrate comprising PbTe crystal of n-type conductivity; epitaxially growing a buffer layer of Pb.sub.(1-x) X x Te n-type conductivity on said substrate, wherein X is a Group VI element selected from the group consisting of S and Se and wherein x is a value greater than 0 but less than 0.1; epitaxially growing an active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wherein y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; annealing said substrate, buffer layer, and active layer at approximately 450° C. for approximately 20 hours to form a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and depositing electrical contact means coupled to said substrate and to said active layer.
Claim 10
Independent Claim
165 words
A method of fabricating a semiconducting device comprising the steps of: providing a substrate comprising PbTe crystal of n-type conductivity; epitaxially growing a buffer layer of Pb.sub.(1-x) X x Te n-type conductivity on said substrate, wherein X is a Group VI element selected from the group consisting of S and Se and wherein x is a value greater than 0 but less than 0.1; epitaxially growing an active layer of Pb.sub.(1-y) Sn y Te on said buffer layer, wherein y is a value greater than 0 but less than 0.3, said active layer forming a heterojunction between said active layer and said buffer layer; annealing said substrate, buffer layer, and active layer at approximately 450° C. for approximately 20 hours to form a p-n junction located outside said buffer layer in either said active layer or in said heterojunction, the n side of said p-n junction being adjacent said buffer layer; and depositing electrical contact means coupled to said substrate and to said active layer.
References Cited (Backward Citations)
US4021836A
Cited
US4048535A
Cited
US4053919A
Cited
US4075043A
Cited
US4064621A
Cited
US4080723A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-07 | 1983-07-09 | 1984-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-07 | 1987-07-09 | 1988-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-07 | 1991-07-09 | 1992-01-08 | $7700.00 | Window Closed / Lapsed |