Semiconductor light-receiving element and method for manufacturing same
The present invention pertains to a semiconductor light-receiving element and a method for manufacturing the same, enabling operation in a wide wavelength bandwidth and achieving fast response and high response efficiency. A PIN type photodiode made by sequentially layering on top of the substrate a Si layer of a first conductivity type, a non-doped Ge layer and a Ge layer of a second conductivity type that is the opposite type of the first conductivity type and a Ge current-blocking mechanism is provided in at least part of the periphery of the PIN type photodiode.
1. A semiconductor light-receiving element comprising:
a substrate of which a surface is a single crystal Si layer;
a PIN type photodiode made by sequentially layering on top of the substrate a Si layer of a first conductivity type, a non-doped Ge layer and a Ge layer of a second conductivity type that is the opposite type of the first conductivity type;
a Ge current blocking mechanism provided in at least a portion in the periphery of the layer structure made of the non-doped Ge layer and the Ge layer of the second conductivity type;
a contact electrode for the second conductivity type provided on the Ge layer of the second conductivity type; and
a contact electrode for the first conductivity type provided in the Si layer of the first conductivity type.
2. The semiconductor light-receiving element according to claim 1 ,
wherein the Ge current blocking mechanism has a structure where a Ge layer of the second conductivity type and a Ge layer of the first conductivity type are layered on top of each other starting from the substrate side, and
a thyristor structure made of a Ge layer of the second conductivity type, a Ge layer of the first conductivity type, a Ge layer of the second conductivity type and a Si layer of the first conductivity type is formed between the contact electrode for the second conductivity type and the contact electrode for the first conductivity type.
3. The semiconductor light-receiving element according to claim 2 ,
wherein the PIN type photodiode has a rectangular parallelepiped form where three sides out of four sides make contact with the Ge current blocking mechanism.
4. The semiconductor light-receiving element according to claim 3 ,
wherein a single crystal Si core layer in stripe for is connected to the Si layer of the first conductivity type via a tapered waveguide on the one side that does not make contact with the Ge current blocking mechanism.
5. The semiconductor light-receiving element according to claim 1 ,
wherein all of the sides of the PIN type photodiode are surrounded by the Ge current blocking mechanism and a top surface of the PIN type photodiode is a surface through which light enters.
6. The semiconductor light-receiving element according to claim 1 ,
wherein the substrate is an SOI substrate where a single crystal Si layer is provided on a single crystal Si substrate with a SiO 2 film in between.