| 摘要 |
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). |
