Patent ID: 11973159
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Semiconductors (Electrical engineering)
Classification: CPC H  G | IPC H

Claim 0:
1. A photodetector comprising:
a silicon (Si) substrate;
a lower clad layer formed on the Si substrate;
a core layer formed on the lower clad layer, the core layer including a waveguide layer configured to guide signal light, and including a first Si slab doped with first conductive impurity ions and a second Si slab doped with second conductive impurity ions;
a germanium (Ge) layer formed on the core layer, the Ge layer configured to absorb light and including a Ge region doped with the first conductive impurity ions;
an upper clad layer formed on the core layer and the Ge layer; and
electrodes respectively connected to the first and second Si slabs and the Ge region,
wherein a region of the core layer sandwiched between the first and second Si slabs operates as an amplification layer,
wherein an electric field applied to a gap between the first and second Si slabs is stronger than an electric field applied to a gap between the Ge region and the second Si slab and causes avalanche amplification,
wherein the second Si slab is formed in a region other than immediately below a region in which the core layer and the Ge layer are in contact with each other,
wherein the region of the core layer is formed to extend over a line immediately below one side of the region in which the core layer and the Ge layer are in contact with each other.