US4839714A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-gain photodetectors made from NIPI mesas with selective lateral contacts
Assignee: HP Inc
•
Filing: 1988-03-14
•
Granted: 1989-06-13
•
Expires: 2008-03-14
Abstract
Abstract A selective contact to a NIPI doping superlattice having a trap free (or low trap density) contact in contact with the layers of the superlattice. In a NIPI superlattice, the trap free region is a doped region that can be produced: by diffusion of dopant ions from a doped metal contact; by overdoping of the edges of the superlattice; or by overgrowth of the edges of the superlattice with a doped material that is trap free.
Inventors
- 👤 Gottfried H. Doehler
- 👤 Caroline J. Scott
- 👤 Gary R. Trott
- 👤 Betty Boatman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:42
CPC Classifications
B; B82; B82Y; B82Y20/00; H; H10; H10F; H10F77/00; H10F77/10; H10F77/14; H10F77/146; H10F77/1468; H10F77/20; H10F77/206
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
74 words
A selective contact to a NIPI superlattice having n-doped and p-doped layers, said contact comprising: a first doped region that is substantially free of trap states and that is in contact with the n- and p-doped layers of the superlattice, said trap state free doped region forming an ohmic contact with a first one of the n- and p-doped layers and forming pn junctions with a second one of the n- and p-doped layers.
Claim 2
Dependent Claim
74 words
A selective contact to a NIPI superlattice having n-doped and p-doped layers, said contact comprising: a first doped region that is substantially free of trap states and that is in contact with the n- and p-doped layers of the superlattice, said trap state free doped region forming an ohmic contact with a first one of the n- and p-doped layers and forming pn junctions with a second one of the n- and p-doped layers.
Claim 3
Dependent Claim
56 words
A selective contact as in claim 1 wherein said first doped region comprises a region of the NIPI superlattice that has been doped by vapor phase diffusion by an amount of dopant that overrides the amount of dopant in the layers of the superlattice, whereby this entire first doped region has a single dominant dopant type.
Claim 4
Dependent Claim
76 words
A selective contact as in claim 2 further comprising: a second doped region containing trap states, said second doped region being in contact with the trap state free doped region, but making no contact with the portion of the superlattice outside of the first doped region; and a metal contact in contact with the second doped region, but not in contact with that part of the NIPI superlattice that is outside of the first doped region.
Claim 5
Dependent Claim
55 words
A selective contact as in claim 1 wherein said first doped region comprises a region of the NIPI superlattice that has been doped by ion implantation by an amount of dopant that overrides the amount of dopant in the layers of the superlattice, whereby this entire first doped region has a single dominant dopant type.
Claim 6
Dependent Claim
76 words
A selective contact as in claim 4 further comprising: a second doped region containing trap states, said second doped region being in contact with the trap state free doped region, but making no contact with the portion of the superlattice outside of the first doped region; and a metal contact in contact with the second doped region, but not in contact with that part of the NIPI superlattice that is outside of the first doped region.
Claim 7
Dependent Claim
25 words
A selective contact as in claim 1 wherein said first doped region comprises an overgrown doped region in contact with the layers of the superlattice.
Claim 8
Dependent Claim
37 words
A selective contact as in claim 6 further comprising a second doped region containing trap states, said second doped region being in contact with the trap state free doped region, but making no contact with the superlattice.
Claim 9
Dependent Claim
113 words
A selective contact as in claim 1 further comprising: a doped metal contact; and a second doped region containing trap states, said second doped region being in contact with the trap state free doped region, but making no contact with the n- and p-doped layers of the superlattice; wherein said metal contact is in contact with the second doped region, said first doped region comprises a region of the NIPI superlattice that has been doped by diffusion of dopant from said doped metal contact by an amount of dopant that overrides the amount of dopant in the layers of the superlattice, whereby this entire first doped region has a single dominant dopant type.
Claim 10
Dependent Claim
26 words
A selective contact as in claim 8 wherein the superlattice is a doped GaAs superlattice and wherein the doped metal consists essentially of nickel and tin.
Claim 11
Dependent Claim
20 words
A selective contact as in claim 9 wherein said metal contact contains between 9 and 11 percent nickel by volume.
Claim 12
Dependent Claim
18 words
A selective contact as in claim 9 wherein the doped metal is between 50 and 60 nm thick.
Claim 13
Dependent Claim
26 words
A selective contact as in claim 8 wherein the superlattice is a doped GaAs superlattice and wherein the doped metal consists essentially of gold and zinc.
Claim 14
Dependent Claim
18 words
A selective contact as in claim 12 wherein said metal contact contains at least 0.5 molar percent zinc.
Claim 15
Dependent Claim
42 words
A selective contact as in claim 12 wherein the metal contact comprises: a layer of gold between 50 and 500 nm thick; a layer of zinc between 10 and 40 nm thick; and a layer of gold at least 100 nm thick.
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) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |