EP0159544A1
Expired / Lapsed
EP
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Avalanche photodiode and its manufacturing method
Assignee: NEC Corp
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Filing: 1985-03-21
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Granted: —
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Expires: 2005-03-21
Abstract
Abstract The avalanche photodiode comprises a light absorbing semiconductor layer (3); an avalanche gain semiconductor layer (4) having a bandgap greater than that of said light absorbing semiconductor layer; a first p-n junction (5) having a substantially p +- n junction and selectively provided in said avalanche gain semiconductor layer (4); a second p-n junction (5') having a substantially graded p-n junction surrounding the periphery of said first p-n junction (5) and a third p-n junction (5") having a substantially graded p-n junction and surrounding the periphery of said second p-n junction (5'). This heterojunction avalanche photodiode is capable of achieving sufficient and uniform avalanche gain in a stepwise p-n junction region corresponding to its light receiving region before a voltage breakdown occurs in its guard ring.
Inventors
- 👤 Yoshimasa Sugimoto
- 👤 Toshitaka Torikai
- 👤 Kenko Taguchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 02:22
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/102; H10D62/103; H10D62/105; H10D62/106; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/225; H10F30/2255
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
83 words
An avalanche photodiode comprises: a light absorbing semiconductor layer; an avalanche gain semiconductor layer having a bandgap greater than that of said light absorbing semiconductor layer; a first p-n junction having a substantially p +-n junction and selectively provided in said avalanche gain semiconductor layer; a second p-n junction having a substantially graded p-n junction surrounding the periphery of said first p-n junction; and a third p-n junction having a substantially graded p-n junction and surrounding the periphery of said second p-n junction.
Claim 2
Dependent Claim
83 words
An avalanche photodiode comprises: a light absorbing semiconductor layer; an avalanche gain semiconductor layer having a bandgap greater than that of said light absorbing semiconductor layer; a first p-n junction having a substantially p +-n junction and selectively provided in said avalanche gain semiconductor layer; a second p-n junction having a substantially graded p-n junction surrounding the periphery of said first p-n junction; and a third p-n junction having a substantially graded p-n junction and surrounding the periphery of said second p-n junction.
Claim 3
Dependent Claim
42 words
An avalanche photodiode, as claimed in Claim 1, wherein said second p-n junction is positioned deeper from the upper surface than said first p-n junction and said third p-n junction is positioned shallower from the upper surface than said second p-n junction.
Claim 4
Independent Claim
128 words
A method for manufacturing an avalanche photodiode comprising steps of: laying, one over another, a light absorbing semiconductor layer and an avalanche gain semiconductor layer having a band-gap larger than that of said light absorbing semiconductor layer; selectively providing in said avalanche gain semiconductor layer a substantially p + -n junction; providing a first substantially graded p-n junction around the periphery of said substantially p +- n junction by implanting beryllium ions; and providing a second substantially graded p-n junction around the periphery of said first substantially graded p-n junction and in contact with said periphery by implanting beryllium ions at an accelerating voltage smaller than that for said first substantially graded p-n junction and in a dosage smaller than that for said first substantially graded p-n junction.
Claim 5
Independent Claim
128 words
A method for manufacturing an avalanche photodiode comprising steps of: laying, one over another, a light absorbing semiconductor layer and an avalanche gain semiconductor layer having a band-gap larger than that of said light absorbing semiconductor layer; selectively providing in said avalanche gain semiconductor layer a substantially p + -n junction; providing a first substantially graded p-n junction around the periphery of said substantially p +- n junction by implanting beryllium ions; and providing a second substantially graded p-n junction around the periphery of said first substantially graded p-n junction and in contact with said periphery by implanting beryllium ions at an accelerating voltage smaller than that for said first substantially graded p-n junction and in a dosage smaller than that for said first substantially graded p-n junction.
Claim 6
Independent Claim
113 words
A method for manufacturing an avalanche photodiode comprising steps of: laying, one over another, a light absorbing semiconductor layer and an avalanche gain semiconductor layer having a band-gap greater than that of said light absorbing semiconductor layer; selectively providing in said avalanche gain semiconductor layer an substantially p + -n junction; and simultaneously forming first and second substantially graded p-n junctions abound the periphery of said substantially p -n junction by implanting beryllium ions into a region through a window selectively bored in an insulating film and through a reduced portion of said insulating film, said reduced portion being thinner than the ion implantation projecting range and surrounding the periphery of said window.
Claim 7
Independent Claim
113 words
A method for manufacturing an avalanche photodiode comprising steps of: laying, one over another, a light absorbing semiconductor layer and an avalanche gain semiconductor layer having a band-gap greater than that of said light absorbing semiconductor layer; selectively providing in said avalanche gain semiconductor layer an substantially p + -n junction; and simultaneously forming first and second substantially graded p-n junctions abound the periphery of said substantially p -n junction by implanting beryllium ions into a region through a window selectively bored in an insulating film and through a reduced portion of said insulating film, said reduced portion being thinner than the ion implantation projecting range and surrounding the periphery of said window.
Claim 8
Independent Claim
104 words
A method for manufacturing an avalanche photodiode comprising steps of: laying, one over another, a light absorbing semiconductor layer and an avalanche gain semiconductor layer having a band-gap greater than that of said light absorbing semiconductor layer; selectively providing in said avalanche gain semiconductor layer a substantially p -n junction; implanting beryllium ions into a region in which a window is selectively bored around said substantially p + -n junction; and simultaneously forming first and second substantially graded p-n junctions by performing activation by thermal treatment after partially removing the surface of the periphery of the region into which beryllium ions have been implanted.
Claim 9
Independent Claim
104 words
A method for manufacturing an avalanche photodiode comprising steps of: laying, one over another, a light absorbing semiconductor layer and an avalanche gain semiconductor layer having a band-gap greater than that of said light absorbing semiconductor layer; selectively providing in said avalanche gain semiconductor layer a substantially p -n junction; implanting beryllium ions into a region in which a window is selectively bored around said substantially p + -n junction; and simultaneously forming first and second substantially graded p-n junctions by performing activation by thermal treatment after partially removing the surface of the periphery of the region into which beryllium ions have been implanted.
References Cited (Backward Citations)
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