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US4079402A Expired / Lapsed US ⏱️ 0.0 years remaining

Zener diode incorporating an ion implanted layer establishing the breakdown point below the surface

Assignee: National Semiconductor Corp
•
Filing: 1973-07-09
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Granted: 1978-03-14
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Expires: 1993-07-09
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Abstract

Abstract A zener diode in which the anode region of a first conductivity material is formed by diffusion in a semiconductor body, a cathode region of a second conductivity material is formed by diffusion in the semiconductor body, and the two regions are bridged by a third region extending through the two regions, the third region being a shallow layer of ion implanted doping material of said first conductivity type. In one embodiment, the anode and cathode regions are spaced-apart; in a second embodiment the cathode region is formed within the anode region. The ion implanted layer has a concentration that peaks below the surface, thus establishing the breakdown point for the avalanching of the zener diode below the surface and removed from surface contaminants such as found in the oxide surface layer.

Inventors

  • 👤 James L. Dunkley
  • 👤 James E. Solomon

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 08:59
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/21; H10D; H10D8/00; H10D8/20; H10D8/25; H10P30/202; H10P30/204; Y; Y10; Y10S; Y10S438/00; Y10S438/983

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 104 words
A subsurface breakdown zener diode on an integrated circuit structure including a diffused anode region of a first conductivity type material formed in the surface of a semiconductor body, a diffused cathode region of a second conductivity type material formed in the surface of said semiconductor body, and a third region extending through said anode and cathode diffused regions, said third region comprising a shallow layer of ion implanted doping material of said first conductivity type and having a lower impurity concentration than that of said diffused cathode region, the impurity concentration of said shallow layer peaking below the surface of said semiconductor body.
Claim 2
Dependent Claim 104 words
A subsurface breakdown zener diode on an integrated circuit structure including a diffused anode region of a first conductivity type material formed in the surface of a semiconductor body, a diffused cathode region of a second conductivity type material formed in the surface of said semiconductor body, and a third region extending through said anode and cathode diffused regions, said third region comprising a shallow layer of ion implanted doping material of said first conductivity type and having a lower impurity concentration than that of said diffused cathode region, the impurity concentration of said shallow layer peaking below the surface of said semiconductor body.
Claim 3
Dependent Claim 27 words
A zener diode structure as claimed in claim 1 wherein said first conductivity type material is P type and said second conductivity type material is N type.
Claim 4
Dependent Claim 39 words
A zener diode structure as claimed in claim 1 wherein said anode and cathode regions are formed in the surface of said semiconductor body in spaced-apart relationship, and said third region bridges across between said anode and cathode regions.
Claim 5
Dependent Claim 27 words
A zener diode structure as claimed in claim 3 wherein said first conductivity type material is P type and said second conductivity type material is N type.
Claim 6
Dependent Claim 19 words
A zener diode structure as claimed in claim 1 wherein said cathode region is formed within said anode region.
Claim 7
Dependent Claim 27 words
A zener diode structure as claimed in claim 5 wherein said first conductivity type material is P type and said second conductivity type material is N type.
Claim 8
Dependent Claim 26 words
A zener diode as claimed in claim 1 wherein said impurity concentration for said shallow layer peaks about 0.5μ below the surface of said semiconductor body.
Claim 9
Dependent Claim 41 words
A zener diode as claimed in claim 1 wherein the impurity concentration for said diffused cathode region is typically 10 21 /cm 3 and the impurity concentration for said shallow layer is about 10 18 to 10 20 /cm 3 .
Claim 10
Dependent Claim 26 words
A zener diode as claimed in claim 8 wherein said impurity concentration for said shallow layer peaks about 0.5μ below the surface of said semiconductor body.

References Cited (Backward Citations)

US3354364A Cited
DE1959817A1 Cited
US3723830A Cited
US3717516A Cited
US3656031A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-03-13 1981-09-12 1982-03-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-03-13 1985-09-12 1986-03-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-03-13 1989-09-12 1990-03-14 $7700.00 Window Closed / Lapsed

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