Patent ID: 11921324
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Semiconductors (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A photodetector comprising:
a semiconductor substrate; and
a light absorption layer formed on the semiconductor substrate,
wherein the photodetector detects signal light incident on the light absorption layer from a direction in a substrate surface of the semiconductor substrate;
the light absorption layer has a region not covered by an electrode for photocurrent detection, the electrode being connected with the light absorption layer, in a case where the substrate surface of the semiconductor substrate is seen from a direction from an outside of the substrate surface wherein
the semiconductor substrate includes:
a silicon substrate;
a lower clad layer formed on the silicon substrate;
a silicon core layer formed on the lower clad layer and having a first semiconductor region; and
an input waveguide connected with the silicon core layer and guiding the signal light as a detection target to the silicon core layer from a direction in the substrate surface,
the light absorption layer is formed on the silicon core layer and includes a germanium layer having a second semiconductor region, and
the electrode for photocurrent detection is connected with a portion of the second semiconductor region.