US4775643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mesa zener diode and method of manufacture thereof
Assignee: Semiconductor Components Industries LLC
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Filing: 1987-06-01
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Granted: 1988-10-04
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Expires: 2007-06-01
Abstract
Abstract A mesa Zener diode is described which is manufactured by ion implanting a region of opposite conductivity into a substrate; etching a moat in a surface of the substrate through the region of opposite conductivity; depositing an oxide layer having an opening exposing a portion of the mesa; and depositing top and bottom metals.
Inventors
- 👤 Thomas A. Wetteroth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:26
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/20; H10D8/25; Y; Y10; Y10S; Y10S148/00; Y10S148/174; Y10S438/00; Y10S438/983
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
120 words
A method of manufacturing a Zener diode comprising the steps: ion implanting a dopant of a first conductivity type into a surface region of a substrate of a second conductivity type; delineating a moat in said substrate such that said moat extends through said surface region, said moat defining a mesa of said substrate; oxidizing a first face of said substrate forming an oxide layer thereon, said first face being adjacent said surface region; delineating an opening within said oxide layer exposing a portion of said mesa; depositing a layer of titanium on said exposed portion of said mesa; depositing a layer of nickel of said layer of titanium; and depositing a layer of silver on said layer of nickel.
Claim 2
Independent Claim
120 words
A method of manufacturing a Zener diode comprising the steps: ion implanting a dopant of a first conductivity type into a surface region of a substrate of a second conductivity type; delineating a moat in said substrate such that said moat extends through said surface region, said moat defining a mesa of said substrate; oxidizing a first face of said substrate forming an oxide layer thereon, said first face being adjacent said surface region; delineating an opening within said oxide layer exposing a portion of said mesa; depositing a layer of titanium on said exposed portion of said mesa; depositing a layer of nickel of said layer of titanium; and depositing a layer of silver on said layer of nickel.
Claim 3
Dependent Claim
49 words
The method of claim 1 wherein said step of delineating a moat comprises the steps of: depositing a layer of photoresist on said first face of said substrate; masking said photoresist to define said moat in said photoresist; developing said photoresist; and etching said substrate through said surface region.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein said step of oxidizing said first face comprises a low temperature oxidation.
Claim 5
Dependent Claim
13 words
The method of claim 3 wherein said low temperature oxidation comprises TEOS oxidation.
Claim 6
Dependent Claim
18 words
The method of claim 1 wherein said step of oxidizing said first face comprises a high pressure oxidation.
Claim 7
Dependent Claim
50 words
The method of claim 1 wherein said step of delineating an opening comprises the steps of: depositing a second photoresist on said oxide layer; masking said second photoresist to define said opening in said photoresist; developing said photoresist; and etching said oxide layer to expose said portion of said mesa.
Claim 8
Dependent Claim
22 words
The method of claim 1 further comprising, following the step of oxidizing said first face, the step of annealing said Zener diode.
Claim 9
Dependent Claim
17 words
The method of claim 7 wherein said step of annealing is performed by a rapid thermal anneal.
Claim 10
Dependent Claim
19 words
The method of claim 7 wherein said step of annealing is performed at a temperature below approximately 1000° C.
Claim 11
Independent Claim
168 words
A method of manufacturing a Zener diode comprising the steps: ion implanting a dopant of a first conductivity type into a surface region of a substrate of a second conductivity type; depositing a layer of photoresist on a first face of said substrate, said first face being adjacent said surface region; masking said photoresist to define a moat in said photoresist; developing said photoresist; etching a moat in said substrate, said moat extending through said surface region and said moat defining a mesa of said substrate; oxidizing a first face of said substrate forming an oxide layer thereon; annealing said Zener diode; depositing a second photoresist on said oxide layer; masking said second photoresist to define an opening in said photoresist; developing said photoresist; etching said oxide layer to expose a porton of said mesa; depositing a layer of titanium on said exposed portion of said mesa; depositing a layer of nickel on said layer of titanium; and depositing a layer of silver on sai layer of nickel.
Claim 12
Independent Claim
168 words
A method of manufacturing a Zener diode comprising the steps: ion implanting a dopant of a first conductivity type into a surface region of a substrate of a second conductivity type; depositing a layer of photoresist on a first face of said substrate, said first face being adjacent said surface region; masking said photoresist to define a moat in said photoresist; developing said photoresist; etching a moat in said substrate, said moat extending through said surface region and said moat defining a mesa of said substrate; oxidizing a first face of said substrate forming an oxide layer thereon; annealing said Zener diode; depositing a second photoresist on said oxide layer; masking said second photoresist to define an opening in said photoresist; developing said photoresist; etching said oxide layer to expose a porton of said mesa; depositing a layer of titanium on said exposed portion of said mesa; depositing a layer of nickel on said layer of titanium; and depositing a layer of silver on sai layer of nickel.
Claim 13
Dependent Claim
18 words
The method of claim 10 wherein said step of oxidizing said first face comprises a low temperature oxidation.
Claim 14
Dependent Claim
18 words
The method of claim 10 wherein said step of oxidizing said first face comprises a high pressure oxidation.
Claim 15
Dependent Claim
17 words
The method of claim 10 wherein said step of annealing is performed by a rapid thermal anneal.
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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) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |