EP0109855A2
Expired / Lapsed
EP
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Photodiode having heterojunction
Assignee: NEC Corp
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Filing: 1983-11-21
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Granted: —
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Expires: 2003-11-21
Abstract
Abstract The photodiode comprises a substrate (6) with an optical epitaxial layer (7) carrying a light-absorbing, avalanche layer (8) formed of InGaAs. This forms a heterojunction with a layer (10) of wider bandgap InP. This in turn forms a PN or Schottky junction with a T region (11, 12). In order to improve the response time there is introduced into the heterojunction a thin layer (9) which is not more than 0.1 micron thick. The thin layer may be InP more highly doped than the contiguous InP layer (10) and/or a thin layer of InGaAs more highly doped than the contiguous InGaAs layer (8).
Inventors
- 👤 Katsuhiko Nishida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 19:31
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/222; H10F30/223; H10F30/225; H10F30/2255
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
84 words
A semiconductor photodiode with a PN or Schottky junction (10-11, 12) and a heterojunction (8-10), formed between first and second semiconductor layers (8 and 10) of a firist conductivity type, characterised by a thin semiconductor layer (9 or 19) between. the first and second layers (8 and 10), the thin layer being of the same conductivity type as the first and second layers, more highly doped than at least one of the first and second layers, and having a thickness not exceeding 0.1 micron.
Claim 2
Dependent Claim
84 words
A semiconductor photodiode with a PN or Schottky junction (10-11, 12) and a heterojunction (8-10), formed between first and second semiconductor layers (8 and 10) of a firist conductivity type, characterised by a thin semiconductor layer (9 or 19) between. the first and second layers (8 and 10), the thin layer being of the same conductivity type as the first and second layers, more highly doped than at least one of the first and second layers, and having a thickness not exceeding 0.1 micron.
Claim 3
Dependent Claim
107 words
A semiconductor photodiode according to claim 1, wherein the first semiconductor layer (8) is on a substrate (6, 7) of the first conductivity type and serves as a light absorbing region, the second semiconductor layer (10) has a wider bandgap than the first layer, and the PN or Schottky junction is formed between the second semiconductor layer (10) and a region (11, 12) of opposite conductivity type also having a wider bandgap than the first layer, characterised in that the thin semiconductor layer (9 or 19) has a wider bandgap than the first semiconductor layer (8) or has a narrower bandgap than the second semiconductor layer (10).
Claim 4
Dependent Claim
57 words
A semiconductor photodiode according to claim 2, characterised in that there are two thin layers, namely one layer (9) contiguous with the second layer (10) and having a wider bandgap than the first semiconductor layer (8), and another layer (19) contiguous with the first layer (8) and having a narrower bandgap than the said one layer (9).
Claim 5
Dependent Claim
28 words
A semiconductor photodiode according to claim l, characterised in that the first layer (8) has a wider bandgap than the second layer (10) and the thin layer (9).
Claim 6
Dependent Claim
28 words
A semiconductor photodiode according to claim 1, characterised in that the second layer (10) has a. narrower bandgap than the first layer (8) and the thin layer (19).
Claim 7
Dependent Claim
65 words
' A semiconductor photodiode according to claim 1, characterised in that there are two thin layers (9, 19) between the first and second layers, the first layer (8) and contiguous thin layer (19) having wider bandgaps than the second layer (10) and its contiguous thin layer (9), each thin layer having a greater impurity concentration than the contiguous one of the first and second layers.
References Cited (Backward Citations)
No citation records indexed.
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