← Back to Patent Explorer
US5396103A Expired / Lapsed US ⏱️ 0.0 years remaining

Graded composition ohmic contact for P-type II-VI semiconductors

Assignee: 3M Co
•
Filing: 1993-02-12
•
Granted: 1995-03-07
•
Expires: 2013-02-12
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A II-VI laser diode including a substrate, a device layer of p-type II-VI semiconductor, an electrode and an ohmic contact layer between the electrode and device layer. The ohmic contact layer comprises a graded composition semiconductor compound including ZnTe. The relative amount of ZnTe in the semiconductor compound increases with increasing distance of the ohmic contact layer from the device layer. In a first embodiment the ohmic contact layer comprises a graded composition semiconductor alloy including the semiconductor compound of the device layer and ZnTe. The amount of ZnTe in the alloy increases with increasing distance of the ohmic contact layer from the device layer in the first embodiment. In a second embodiment the ohmic contact layer includes layers of ZnTe spaced between layers of the semiconductor compound of the device layer. The thickness of the layers of ZnTe increase, or the thickness of the layers of the semiconductor compound of the device layer decrease, with increasing distance of the ohmic contact layer from the device layer in the second embodiment.

Inventors

  • 👤 Jun Oiu
  • 👤 James M. DePuydt
  • 👤 Hwa Cheng
  • 👤 Michael A. Haase

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 19:13
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/30; H01S5/305; H01S5/3054; H01S5/3059; B; B82; B82Y; B82Y20/00; H01S5/04; H01S5/042; H01S5/0421; H01S5/20; H01S5/22; H01S5/2205; H01S5/2211; H01S5/223; H01S5/2231; H01S5/3068; H01S5/32; H01S5/327; H01S5/34; H01S5/3403; H01S5/347; H10; H10D; H10D64/00; H10D64/60; H10D64/62; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/012; H10H20/0125; H10H20/032; H10H20/80; H10H20/81; H10H20/816; H10H20/8162; H10H20/822; H10H20/823; H10H20/8232; H10H20/83; H10H20/831; H10H20/832

Claims Analysis

Total Claims: 40
Claim 1
Independent Claim 64 words
A semiconductor device including: a substrate; a p-type II-VI semiconductor compound device layer; an electrode; and a p-type ohmic contact layer between the device layer and electrode and including: a first semiconductor compound; a second semiconductor compound including ZnTe; and the relative average amount of ZnTe in the ohmic contact layer increases with increasing distance of the ohmic contact layer from the device layer.
Claim 2
Dependent Claim 64 words
A semiconductor device including: a substrate; a p-type II-VI semiconductor compound device layer; an electrode; and a p-type ohmic contact layer between the device layer and electrode and including: a first semiconductor compound; a second semiconductor compound including ZnTe; and the relative average amount of ZnTe in the ohmic contact layer increases with increasing distance of the ohmic contact layer from the device layer.
Claim 3
Dependent Claim 46 words
The semiconductor device of claim 1 wherein the composition of the first semiconductor compound varies throughout the p-type ohmic contact layer and an average lattice constant of the ohmic contact layer is close to the lattice constant of the device layer throughout the ohmic contact layer.
Claim 4
Dependent Claim 15 words
The semiconductor device of claim 1 wherein the composition of the first semiconductor compound varies.
Claim 5
Dependent Claim 25 words
The semiconductor device of claim 1 wherein the first semiconductor compound of the p-type ohmic contact layer includes the semiconductor compound of the device layer.
Claim 6
Dependent Claim 26 words
The semiconductor device of claim 1 wherein the first semiconductor compound of the p-type ohmic contact layer consists of the semiconductor compound of the device layer.
Claim 7
Dependent Claim 48 words
The semiconductor device of claim 1 wherein the p-type ohmic contact layer comprises a graded composition semiconductor alloy including the first and second semiconductor compounds, and the relative average amount of ZnTe in the alloy increases with increasing distance of the ohmic contact layer from the device layer.
Claim 8
Dependent Claim 56 words
The semiconductor device of claim 6 wherein: the device layer includes a layer of p-type ZnSe; and the ohmic contact layer comprises a graded composition semiconductor alloy including ZnSe and ZnTe in which the amount of ZnTe increases and the amount of ZnSe decreases with increasing distance of the ohmic contact layer from the device layer.
Claim 9
Dependent Claim 46 words
The semiconductor device of claim 7 wherein the semiconductor alloy of the ohmic contact layer includes ZnSe 1-x Te x , where x increases from a value of about 0 adjacent the device layer to a value greater than or equal to 0.1 adjacent the electrode.
Claim 10
Dependent Claim 18 words
The semiconductor device of claim 7 wherein the semiconductor alloy of the ohmic contact layer includes nitrogen-doped ZnSeTe.
Claim 11
Dependent Claim 56 words
The semiconductor device of claim 6 wherein: the device layer includes a layer of p-type ZnS; and the ohmic contact layer comprises a graded composition semiconductor alloy including ZnS and ZnTe in which the amount of ZnTe increases and the amount of ZnS decreases with increasing distance of the ohmic contact layer from the device layer.
Claim 12
Dependent Claim 18 words
The semiconductor device of claim 10 wherein the semiconductor alloy of the ohmic contact layer includes nitrogen-doped ZnSeTe.
Claim 13
Dependent Claim 26 words
The semiconductor device of claim 1 wherein the ohmic contact layer includes layers of the second semiconductor compound spaced between layers of the first semiconductor compound.
Claim 14
Dependent Claim 14 words
The semiconductor device of claim 12 wherein the second semiconductor compound consists of ZnTe.
Claim 15
Dependent Claim 17 words
The semiconductor device of claim 12 wherein the first semiconductor compound is lattice-matched to the device layer.
Claim 16
Dependent Claim 32 words
The semiconductor device of claim 12 wherein the composition of the first semiconductor compound varies throughout the p-type ohmic contact layer so the ohmic contact layer is lattice-matched to the device layer.
Claim 17
Dependent Claim 19 words
The semiconductor device of claim 12 wherein the first semiconductor compound includes the semiconductor compound of the device layer.
Claim 18
Dependent Claim 30 words
The semiconductor device of claim 12 wherein the spacing between the layers of the second semiconductor compound decreases with increasing distance of the ohmic contact layer from the device layer.
Claim 19
Dependent Claim 31 words
The semiconductor device of claim 12 wherein the average thickness of the layers of the second semiconductor compound increases with increasing distance of the ohmic contact layer from the device layer.
Claim 20
Dependent Claim 13 words
The semiconductor device of claim 1 wherein the electrode includes a metallic electrode.
Claim 21
Dependent Claim 13 words
The semiconductor device of claim 1 wherein the device is a laser diode.
Claim 22
Dependent Claim 14 words
The semiconductor device of claim 1 wherein the device is a light emitting diode.
Claim 23
Dependent Claim 56 words
The semiconductor device of claim 6 wherein: the device layer includes a layer of p-type ZnSSe; and the ohmic contact layer comprises a graded composition semiconductor alloy including ZnSe and ZnTe in which the amount of ZnSe decreases and the amount of ZnTe increases with increasing distance of the ohmic contact layer from the device layer.
Claim 24
Dependent Claim 56 words
The semiconductor device of claim 6 wherein: the device layer includes a layer of p-type ZnSSe; and the ohmic contact layer comprises a graded composition semiconductor alloy including ZnS and ZnTe in which the amount of ZnS decreases and the amount of ZnTe increases with increasing distance of the ohmic contact layer from the device layer.
Claim 25
Dependent Claim 29 words
The semiconductor device of claim 12 wherein: the device layer includes a layer of p-type ZnSSe; the first semiconductor compound includes ZnSe; and the second semiconductor compound includes ZnTe.
Claim 26
Dependent Claim 29 words
The semiconductor device of claim 12 wherein: the device layer includes a layer of p-type ZnSSe; the first semiconductor compound includes ZnS; and the second semiconductor compound includes ZnTe.
Claim 27
Dependent Claim 10 words
An electronic system including the semiconductor device of claim 1.
Claim 28
Dependent Claim 14 words
An electronic system including the laser diode of claim 20 as a light source.
Claim 29
Dependent Claim 28 words
The semiconductor device of claim 1 wherein the p-type ohmic contact layer is capable of continuously conducting current at densities of at least about 1000 A/cm 2 .
Claim 30
Dependent Claim 67 words
A II-VI compound semiconductor laser diode, including: a p-type II-VI semiconductor compound device layer; an electrode; and a continuously graded p-type ohmic contact layer between the device layer and electrode, the ohmic contact layer including a first semiconductor compound and a second semiconductor compound including ZnTe, and wherein the relative average amount of ZnTe increases with increasing distance of the ohmic contact layer from the device layer.
Claim 31
Dependent Claim 67 words
A II-VI compound semiconductor laser diode, including: a p-type II-VI semiconductor compound device layer; an electrode; and a continuously graded p-type ohmic contact layer between the device layer and electrode, the ohmic contact layer including a first semiconductor compound and a second semiconductor compound including ZnTe, and wherein the relative average amount of ZnTe increases with increasing distance of the ohmic contact layer from the device layer.
Claim 32
Dependent Claim 51 words
The laser diode of claim 29 wherein the p-type ohmic contact layer comprises a continuously graded composition semiconductor alloy including the II-VI semiconductor compound of the device layer and ZnTe, and wherein the relative average amount of ZnTe increases with increasing distance of the ohmic contact layer from the device layer.
Claim 33
Dependent Claim 14 words
An electronic system including the laser diode of claim 30 as a light source.
Claim 34
Dependent Claim 72 words
A II-VI compound semiconductor laser diode, including: a p-type II-VI semiconductor compound device layer; an electrode; and a digitally graded p-type ohmic contact layer between the device layer and electrode, the ohmic contact layer including layers of a first semiconductor compound spaced between layers of a second semiconductor compound including ZnTe, and wherein the relative average amount of ZnTe increases with increasing distance of the ohmic contact layer from the device layer.
Claim 35
Dependent Claim 72 words
A II-VI compound semiconductor laser diode, including: a p-type II-VI semiconductor compound device layer; an electrode; and a digitally graded p-type ohmic contact layer between the device layer and electrode, the ohmic contact layer including layers of a first semiconductor compound spaced between layers of a second semiconductor compound including ZnTe, and wherein the relative average amount of ZnTe increases with increasing distance of the ohmic contact layer from the device layer.
Claim 36
Dependent Claim 35 words
The laser diode of claim 32 wherein the spacing between the layers of the second semiconductor compound in the ohmic contact layer decreases with increasing distance of the ohmic contact layer from the device layer.
Claim 37
Dependent Claim 36 words
The laser diode of claim 32 wherein the average thickness of the layers of the second semiconductor compound in the ohmic contact layer increases with increasing thickness of the ohmic contact layer from the device layer.
Claim 38
Dependent Claim 30 words
The laser diode of claim 32 wherein the digitally graded p-type ohmic contact layer includes layers of the II-VI semiconductor compound of the device layer spaced between layers of ZnTe.
Claim 39
Dependent Claim 14 words
An electronic system including the laser diode of claim 35 as a light source.
Claim 40
Dependent Claim 28 words
The laser diode of claim 32 wherein the p-type ohmic contact layer is capable of continuously conducting current at densities of at least about 1000 A/cm 2 .

References Cited (Backward Citations)

US4063269A Cited
US4236829A Cited
US4801984A Cited
US4794440A Cited
US4866490A Cited
US4600932A Cited
US4768074A Cited
US4795501A Cited
US5093704A Cited
US5148267A Cited
US5213998A Cited
US5294833A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-03-06 1998-09-05 1999-03-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-03-06 2002-09-05 2003-03-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-03-06 2006-09-05 2007-03-07 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag