Patent US4429324A successfully refreshed from Google Patents.
US4429324A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zener diode and method of making the same
Assignee: US Philips Corp
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Filing: 1981-07-20
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Granted: 1984-01-31
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Expires: 2001-07-20
Abstract
Abstract The present invention provides an improved Zener diode structure which avoids adverse structure causing leakage current or short circuits, for example. The pn junction is formed on a region of a first conductivity material below a window on the surface of the material. A second conductivity material fills the window to form the pn junction, and forms a sub-region at least at the edges of the window and extending substantially below the pn junction to maintain the pn junction far from the edges of the window.
Inventors
- 👤 Aubin U. Wilkens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:56
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/20; H10D8/25
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
169 words
A Zener diode comprising a semiconductor body providing a first semiconductor region of a first conductivity type adjoining a surface of said body, a protective insulating layer on said surface having a window for exposing a portion of said surface, wherein said first semiconductor region includes a main region below and spaced apart from said surface and being within said window, said main region having an impurity concentration density of the first type, an epitaxial layer of a second conductivity type provided on and above said surface; a second region of said second conductivity type extending from said epitaxial layer to said main region and forming a pn junction therebetween, a sub-region of said second conductivity type surrounding said main region and said second region and extending at least below edges of said window, said sub-region extending substantially further below said surface than said pn junction, and said sub-region maintaining said pn junction for Zener effect far from said edges, and a metal conductor provided over said epitaxial layer.
Claim 2
Dependent Claim
169 words
A Zener diode comprising a semiconductor body providing a first semiconductor region of a first conductivity type adjoining a surface of said body, a protective insulating layer on said surface having a window for exposing a portion of said surface, wherein said first semiconductor region includes a main region below and spaced apart from said surface and being within said window, said main region having an impurity concentration density of the first type, an epitaxial layer of a second conductivity type provided on and above said surface; a second region of said second conductivity type extending from said epitaxial layer to said main region and forming a pn junction therebetween, a sub-region of said second conductivity type surrounding said main region and said second region and extending at least below edges of said window, said sub-region extending substantially further below said surface than said pn junction, and said sub-region maintaining said pn junction for Zener effect far from said edges, and a metal conductor provided over said epitaxial layer.
Claim 3
Dependent Claim
29 words
A Zener diode according to claim 1, wherein said sub-region extends below said surface to a depth at least twice the depth of said pn junction below said surface.
Claim 4
Dependent Claim
32 words
A Zener diode according to claim 2, wherein said depth of said pn junction for Zener effect is approximately 500 Angstroms, and said depth of said sub-region is at least 1000 Angstroms.
Claim 5
Dependent Claim
32 words
A Zener diode according to claim 3, wherein the impurity concentration gradient on either side of said pn junction for Zener effect is between 10 23 and 10 24 atoms/cm 4 .
Claim 6
Dependent Claim
40 words
A Zener diode according to claim 1, wherein said sub-region extends below said surface to a depth of at least 1,000 Angstroms, and said pn junction for Zener effect extends below said surface to a depth of approximately 500 Angstroms.
Claim 7
Dependent Claim
32 words
A Zener diode according to claim 5, wherein the impurity concentration gradient on either side of said pn junction for Zener effect is between 10 23 and 10 24 atoms/cm 4 .
Claim 8
Dependent Claim
32 words
A Zener diode according to claim 2, wherein the impurity concentration gradient on either side of said pn junction for Zener effect is between 10 23 and 10 24 atoms/cm 4 .
Claim 9
Dependent Claim
32 words
A Zener diode according to claim 1, wherein the impurity concentration gradient on either side of said pn junction for Zener effect is between 10 23 and 10 24 atoms/cm 4 .
Claim 10
Dependent Claim
38 words
A Zener diode according to claim 1, wherein said main region includes a zone of relatively low resistivity, said zone having a higher impurity concentration of said first conductivity type than surrounding portions of said first semiconductor region.
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) | 1987-01-30 | 1987-08-01 | 1988-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-30 | 1991-08-01 | 1992-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-30 | 1995-08-01 | 1996-01-31 | $7700.00 | Window Closed / Lapsed |