| 摘要 |
PURPOSE:To obtain the light receiving element having a little noise by a method wherein an incident light absorption region, having a conduction type which differs from that of a semiconductor layer, is provided within the semiconductor layer which converts the light into an electric current by a depletion region which is developed when the light is incidented on the side of an incident surface. CONSTITUTION:On an InP substrate 2, an N type InP layer 3, a non-doped InGaAsP layer 4, a P-type InP layer 5 and P<+>-type InP layer 7 are laminated, an N side electrode 1 is formed on the reverse side of the substrate 2 and a ring type P side electrode 8 is formed on the layer 7 respectively and they are used as the light receiving elemens. In this constitution, an N-type incident ray absorption region 6 consisted of a ring type InGaAsP or an InGaAs is newly added to the layer 7. The elements are constituted as above and when an inverse bias is applied to the junction, consisted of layers 4 and 5, and the depletion layer developed here is changed to an active region, a current flows only by the light incidented to the section which does not have the region 6 and the light 9 incidented into the region 6 is absorbed here and it is not developed into a noise ingredient. |
