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US5818072A
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Integrated heterostructure of group II-VI semiconductor materials including epitaxial ohmic contact and method of fabricating same
Assignee: North Carolina State University
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Filing: 1992-05-12
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Granted: 1998-10-06
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Expires: 2012-05-12
Abstract
Abstract An ohmic contact to a p-type zinc selenide (ZnSe) layer in a Group II-VI semiconductor device, includes a zinc mercury selenide (Zn x Hg 1-x Se) layer on the zinc selenide layer, a mercury selenide (HgSe) layer on the zinc mercury selenide layer and a conductor (such as metal) layer on the mercury selenide layer. The zinc mercury selenide and mercury selenide layers between the p-type zinc selenide and the conductor layer provide an ohmic contact by eliminating the band offset between the wide bandgap zinc selenide and the conductor. Step graded, linear graded, and parabolic graded layers of zinc mercury selenide may be provided. A layer of mercury selenide without the mercury zinc selenide layer may also provide an ohmic contact. The ohmic contact of the present invention produces nearly ideal voltage-current relation, so that high efficiency Group II-VI optoelectronic devices may be obtained. The integrated heterostructure is formed by epitaxially depositing the ohmic contact on the Group II-VI device. A removable overcoat layer may be formed on the Group II-VI device to allow room temperature atmospheric pressure transfer of the device from a zinc based deposition chamber to a mercury based deposition chamber, for deposition of the ohmic contact.
Inventors
- 👤 Jan Frederick Schetzina
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:25
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/83; H10H20/832; B; B82; B82Y; B82Y20/00; H01; H01S; H01S5/00; H01S5/04; H01S5/042; H01S5/0421; H10D; H10D64/00; H10D64/01; H10D64/011; H10H20/01; H10H20/011; H10H20/012; H10H20/81; H10H20/822; H10H20/823; H01S5/02; H01S5/0206; H01S5/0215; H01S5/10; H01S5/18; H01S5/183; H01S5/30; H01S5/305; H01S5/3095; H01S5/32; H01S5/3211; H01S5/3215; H01S5/327; H01S5/34; H01S5/347; Y; Y10; Y10S; Y10S148/00; Y10S148/064; Y10S438/00; Y10S438/936
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
101 words
An ohmic contact for a semiconductor device formed of Group II-VI compound semiconductor materials and including a layer of p-type zinc selenide (ZnSe) or an alloy thereof, said ohmic contact comprising: a zinc mercury selenide (Zn x Hg 1-x Se) layer on said layer of p-type ZnSe or an alloy thereof, where O<x<1; a mercury selenide (HgSe) layer on said Zn x Hg 1-x Se layer; and a conductor layer on said HgSe layer, said Zn x Hg 1-x Se layer and said HgSe layer forming an ohmic contact between said p-type ZnSe or an alloy thereof, and said conductor layer.
Claim 2
Dependent Claim
101 words
An ohmic contact for a semiconductor device formed of Group II-VI compound semiconductor materials and including a layer of p-type zinc selenide (ZnSe) or an alloy thereof, said ohmic contact comprising: a zinc mercury selenide (Zn x Hg 1-x Se) layer on said layer of p-type ZnSe or an alloy thereof, where O<x<1; a mercury selenide (HgSe) layer on said Zn x Hg 1-x Se layer; and a conductor layer on said HgSe layer, said Zn x Hg 1-x Se layer and said HgSe layer forming an ohmic contact between said p-type ZnSe or an alloy thereof, and said conductor layer.
Claim 3
Dependent Claim
29 words
The ohmic contact of claim 1 wherein x is constant in said Zn x Hg 1-x Se layer to provide a step graded Zn x Hg 1-x Se layer.
Claim 4
Dependent Claim
35 words
The ohmic contact of claim 1 wherein x decreases across said Zn x Hg 1-x Se layer, from said ZnSe layer to said HgSe layer, to provide a graded Zn x Hg 1-x Se layer.
Claim 5
Dependent Claim
37 words
The ohmic contact of claim 3 wherein x decreases linearly across said Zn x Hg 1-x Se layer, from said ZnSe layer to said HgSe layer, to provide a linear graded Zn x Hg 1-x Se layer.
Claim 6
Dependent Claim
37 words
The ohmic contact of claim 3 wherein x decreases nonlinearly across said Zn x Hg 1-x Se layer, from said ZnSe layer to said HgSe layer, to provide a nonlinear graded Zn x Hg 1-x Se layer.
Claim 7
Dependent Claim
37 words
The ohmic contact of claim 5 wherein x decreases parabolically across said Zn x Hg 1-x Se layer, from said ZnSe layer to said HgSe layer, to provide a parabolic graded Zn x Hg 1-x Se layer.
Claim 8
Dependent Claim
43 words
The ohmic contact of claim 6 wherein a first half of said Zn x Hg 1-x Se layer adjacent said ZnSe is p-type, and a second half of said Zn x Hg 1-x Se layer adjacent said HgSe layer is of neutral conductivity.
Claim 9
Dependent Claim
21 words
The ohmic contact of claim 1 wherein at least a portion of said Zn x Hg 1-x Se layer is p-type.
Claim 10
Dependent Claim
29 words
The ohmic contact of claim 8 wherein said Zn x Hg 1-x Se layer is p-type adjacent said ZnSe layer, and is of neutral conductivity adjacent said Hgse layer.
Claim 11
Dependent Claim
16 words
The ohmic contact of claim 1 wherein said zinc mercury selenide layer is p-type modulation doped.
Claim 12
Dependent Claim
95 words
An ohmic contact for a semiconductor device formed of Group II-VI compound semiconductor materials and including a layer of p-type Group II-VI compound semiconductor material, said ohmic contact comprising: a ternary compound Group II-VI semiconductor material on said layer of p-type Group II-VI compound semiconductor material; a Group II-VI semimetal on said ternary compound Group II-VI semiconductor material; and a conductor on said Group II-VI semimetal, said ternary compound Group II-VI semiconductor material and said Group II-VI semimetal forming an ohmic contact between said layer of p-type Group II-VI compound semiconductor material and said conductor.
Claim 13
Dependent Claim
95 words
An ohmic contact for a semiconductor device formed of Group II-VI compound semiconductor materials and including a layer of p-type Group II-VI compound semiconductor material, said ohmic contact comprising: a ternary compound Group II-VI semiconductor material on said layer of p-type Group II-VI compound semiconductor material; a Group II-VI semimetal on said ternary compound Group II-VI semiconductor material; and a conductor on said Group II-VI semimetal, said ternary compound Group II-VI semiconductor material and said Group II-VI semimetal forming an ohmic contact between said layer of p-type Group II-VI compound semiconductor material and said conductor.
Claim 14
Dependent Claim
18 words
The ohmic contact of claim 11 wherein said ternary compound Group II-VI semiconductor material is zinc mercury selenide.
Claim 15
Dependent Claim
14 words
The ohmic contact of claim 11 wherein said Group II-VI semimetal is mercury selenide.
Claim 16
Dependent Claim
12 words
The ohmic contact of claim 11 wherein said conductor is a metal.
Claim 17
Dependent Claim
23 words
The ohmic contact of claim 11 wherein said ternary compound Group II-VI semiconductor material and said Group II-VI semimetal form a monocrystalline heterostructure.
Claim 18
Dependent Claim
86 words
An ohmic contact for a semiconductor device formed of Group II-VI compound semiconductor materials and including a layer of p-type zinc selenide (ZnSe) or an alloy thereof, said ohmic contact comprising: a mercury selenide (HgSe) heterostructure on said p-type ZnSe layer; and a conductor layer on said HgSe heterostructure, said conductor layer being spaced from said p-type Z n S e layer by said H g S e heterostructure, said HgSe heterostructure forming an ohmic contact between said layer of p-type ZnSe and said conductor layer.
Claim 19
Dependent Claim
86 words
An ohmic contact for a semiconductor device formed of Group II-VI compound semiconductor materials and including a layer of p-type zinc selenide (ZnSe) or an alloy thereof, said ohmic contact comprising: a mercury selenide (HgSe) heterostructure on said p-type ZnSe layer; and a conductor layer on said HgSe heterostructure, said conductor layer being spaced from said p-type Z n S e layer by said H g S e heterostructure, said HgSe heterostructure forming an ohmic contact between said layer of p-type ZnSe and said conductor layer.
Claim 20
Dependent Claim
14 words
The ohmic contact of claim 16 wherein said conductor layer is a metal layer.
Claim 21
Dependent Claim
105 words
A semiconductor device formed of Group II-VI compound semiconductor materials comprising: an optical emission heterostructure formed of Group II-VI compound semiconductor materials, and including a layer of p-type zinc selenide (ZnSe) or an alloy thereof; a zinc mercury selenide (Zn x Hg 1-x Se) layer on said layer of p-type ZnSe or an alloy thereof, where O<x<1; a mercury selenide (HgSe) layer on said Zn x Hg 1-x Se layer; and a conductor layer on said HgSe layer, said Zn x Hg 1-x Se layer and said HgSe layer forming an ohmic contact between said p-type ZnSe or an alloy thereof, and said conductor layer.
Claim 22
Dependent Claim
105 words
A semiconductor device formed of Group II-VI compound semiconductor materials comprising: an optical emission heterostructure formed of Group II-VI compound semiconductor materials, and including a layer of p-type zinc selenide (ZnSe) or an alloy thereof; a zinc mercury selenide (Zn x Hg 1-x Se) layer on said layer of p-type ZnSe or an alloy thereof, where O<x<1; a mercury selenide (HgSe) layer on said Zn x Hg 1-x Se layer; and a conductor layer on said HgSe layer, said Zn x Hg 1-x Se layer and said HgSe layer forming an ohmic contact between said p-type ZnSe or an alloy thereof, and said conductor layer.
Claim 23
Dependent Claim
29 words
The semiconductor device of claim 18 wherein x is constant in said Zn x Hg 1-x Se layer to provide a step graded Zn x Hg 1-x Se layer.
Claim 24
Dependent Claim
35 words
The semiconductor device of claim 18 wherein x decreases across said Zn x Hg 1-x Se layer, from said ZnSe layer to said HgSe layer, to provide a graded Zn x Hg 1-x Se layer.
Claim 25
Dependent Claim
37 words
The semiconductor device of claim 20 wherein x decreases linearly across said Zn x Hg 1-x Se layer, from said ZnSe layer to said HgSe layer, to provide a linear graded Zn x Hg 1-x Se layer.
Claim 26
Dependent Claim
37 words
The semiconductor device of claim 20 wherein x decreases nonlinearly across said Zn x Hg 1-x Se layer, from said ZnSe layer to said HgSe layer, to provide a nonlinear graded Zn x Hg 1-x Se layer.
Claim 27
Dependent Claim
37 words
The semiconductor device of claim 22 wherein x decreases parabolically across said Zn x Hg 1-x Se layer, from said ZnSe layer to said Hgse layer, to provide a parabolic graded Zn x Hg 1-x Se layer.
Claim 28
Dependent Claim
44 words
The semiconductor device of claim 23 wherein a first half of said Zn x Hg 1-x Se layer adjacent said ZnSe layer is p-type, and a second half of said Zn x Hg 1-x Se layer adjacent said HgSe layer is of neutral conductivity.
Claim 29
Dependent Claim
21 words
The semiconductor device of claim 18 wherein at least a portion of said Zn x Hg 1-x Se layer is p-type.
Claim 30
Dependent Claim
29 words
The semiconductor device of claim 25 wherein said Zn x Hg 1-x Se layer is p-type adjacent said ZnSe layer, and is of neutral conductivity adjacent said HgSe layer.
Claim 31
Dependent Claim
16 words
The semiconductor device of claim 18 wherein said zinc mercury selenide layer is p-type modulation doped.
Claim 32
Dependent Claim
99 words
A semiconductor device formed of Group II-VI compound semiconductor materials, comprising: an optical emission heterostructure formed of Group II-VI compound semiconductor materials and including a layer of p-type Group II-VI compound semiconductor material; a ternary compound Group II-VI semiconductor material on said layer of p-type Group II-VI compound semiconductor material; a Group II-VI semimetal on said ternary compound Group II-VI semiconductor material; and a conductor on said Group II-VI semimetal, said ternary compound Group II-VI semiconductor material and said Group II-VI semimetal forming an ohmic contact between said layer of p-type Group II-VI compound semiconductor material and said conductor.
Claim 33
Dependent Claim
99 words
A semiconductor device formed of Group II-VI compound semiconductor materials, comprising: an optical emission heterostructure formed of Group II-VI compound semiconductor materials and including a layer of p-type Group II-VI compound semiconductor material; a ternary compound Group II-VI semiconductor material on said layer of p-type Group II-VI compound semiconductor material; a Group II-VI semimetal on said ternary compound Group II-VI semiconductor material; and a conductor on said Group II-VI semimetal, said ternary compound Group II-VI semiconductor material and said Group II-VI semimetal forming an ohmic contact between said layer of p-type Group II-VI compound semiconductor material and said conductor.
Claim 34
Dependent Claim
18 words
The semiconductor device of claim 28 wherein said ternary compound Group II-VI semiconductor material is zinc mercury selenide.
Claim 35
Dependent Claim
14 words
The semiconductor device of claim 28 wherein said Group II-VI semimetal is mercury selenide.
Claim 36
Dependent Claim
12 words
The semiconductor device of claim 28 wherein said conductor is a metal.
Claim 37
Dependent Claim
23 words
The semiconductor device of claim 28 wherein said ternary compound Group II-VI semiconductor material and said Group II-VI semimetal form a monocrystalline heterostructure.
Claim 38
Dependent Claim
90 words
A semiconductor device formed of Group II-VI compound semiconductor materials, comprising: an optical emission heterostructure formed of Group II-VI compound semiconductor materials, and including a layer of p-type zinc selenide (ZnSe) or an alloy thereof; a mercury selenide (HgSe) heterostructure on said p-type ZnSe layer; and a conductor layer on said HgSe heterostructure, said conductor layer being spaced from said p-type Z n S e layer by said H g S e heterostructure, said HgSe heterostructure forming an ohmic contact between said layer of p-type ZnSe and said conductor layer.
Claim 39
Dependent Claim
90 words
A semiconductor device formed of Group II-VI compound semiconductor materials, comprising: an optical emission heterostructure formed of Group II-VI compound semiconductor materials, and including a layer of p-type zinc selenide (ZnSe) or an alloy thereof; a mercury selenide (HgSe) heterostructure on said p-type ZnSe layer; and a conductor layer on said HgSe heterostructure, said conductor layer being spaced from said p-type Z n S e layer by said H g S e heterostructure, said HgSe heterostructure forming an ohmic contact between said layer of p-type ZnSe and said conductor layer.
Claim 40
Dependent Claim
14 words
The semiconductor device of claim 33 wherein said conductor layer is a metal layer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2001-10-05 | 2002-04-06 | 2002-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-05 | 2006-04-06 | 2006-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-05 | 2010-04-06 | 2010-10-06 | $7700.00 | Window Closed / Lapsed |