Patent US5804877A successfully refreshed from Google Patents.
US5804877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-resistance contact on a compound semiconductor
Assignee: Triquint Semiconductor Texas Inc
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Filing: 1996-06-20
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Granted: 1998-09-08
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Expires: 2016-06-20
Abstract
Abstract Generally, and in one form of the invention, a method is disclosed for forming an ohmic contact on a GaAs surface 20 comprising the steps of depositing a layer of InGaAs 22 over the GaAs surface 20, and depositing a layer of TiW 24 on the layer of InGaAs 22, whereby a reliable and stable electrical contact is established to the GaAs surface 20 and whereby Ti does not generally react with the In.
Inventors
- 👤 Clyde R. Fuller
- 👤 Joseph B. Delaney
- 👤 Thomas E. Nagle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:36
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/80; H10D10/821; H10D64/00; H10D64/60; H10D64/62; H10D62/00; H10D62/80; H10D62/82; H10D62/824; H10D62/85
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
27 words
An ohmic contact to a GaAs surface comprising: a layer of InGaAs over said GaAs surface; and a layer of TiW ohmically contacting said layer of InGaAs.
Claim 2
Dependent Claim
27 words
An ohmic contact to a GaAs surface comprising: a layer of InGaAs over said GaAs surface; and a layer of TiW ohmically contacting said layer of InGaAs.
Claim 3
Dependent Claim
19 words
The ohmic contact of claim 1 wherein said layer of InGaAs is In 0 .5 Ga 0 .5 As.
Claim 4
Dependent Claim
25 words
The ohmic contact of claim 1 wherein said layer of InGaAs is doped with Si to a concentration of approximately 1×10 19 cm -3 .
Claim 5
Dependent Claim
23 words
The ohmic contact of claim 1 further comprising a composition of metal on said layer of TiW, said composition of metal containing Au.
Claim 6
Dependent Claim
16 words
The ohmic contact of claim 4 wherein said composition of metal comprises Ti, Pt, and Au.
Claim 7
Dependent Claim
33 words
A bipolar transistor comprising: a mesa, said mesa comprising: a first semiconductor layer; a layer of InGaAs atop said first semiconductor layer; and a layer of TiW ohmically contacting said layer of InGaAs.
Claim 8
Dependent Claim
33 words
A bipolar transistor comprising: a mesa, said mesa comprising: a first semiconductor layer; a layer of InGaAs atop said first semiconductor layer; and a layer of TiW ohmically contacting said layer of InGaAs.
Claim 9
Dependent Claim
22 words
The bipolar transistor of claim 6 wherein said mesa is a collector mesa and said first semiconductor layer is a collector layer.
Claim 10
Dependent Claim
22 words
The transistor of claim 6 further comprising a composition of metal on said layer of TiW, said composition of metal containing Au.
Claim 11
Dependent Claim
18 words
The transistor of claim 6 wherein said layer of InGaAs is In 0 .5 Ga 0 .5 As.
Claim 12
Dependent Claim
24 words
The bipolar transistor of claim 6 wherein said mesa is an emitter mesa and said first semiconductor layer is a wide bandgap emitter layer.
Claim 13
Dependent Claim
25 words
The bipolar transistor of claim 10 wherein said emitter mesa further comprises a layer of GaAs between said emitter layer and said layer of InGaAs.
Claim 14
Dependent Claim
11 words
The transistor of claim 10 wherein said emitter layer is AlGaAs.
Claim 15
Dependent Claim
11 words
The transistor of claim 10 wherein said emitter layer is GaInP.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-07 | 2002-03-09 | 2002-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-07 | 2006-03-09 | 2006-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-07 | 2010-03-09 | 2010-09-08 | $7700.00 | Window Closed / Lapsed |