Light Receiving Element
There is provided a light receiving element capable of maintaining high speed and high sensitivity without a flip-chip packaging process when the light receiving element is mounted on an optical receiver. The light receiving element includes a first electrode metal formed on a top surface of the substrate, a semiconductor layer bonded to a top surface of the first electrode metal, and a second electrode metal formed on a top surface of the semiconductor layer. The semiconductor layer includes a first semiconductor contact layer, a second semiconductor contact layer, and a semiconductor absorbing layer between the first semiconductor contact layer and the second semiconductor contact layer. The first electrode metal has an extraction path for propagating a signal to an anode electrode or a cathode electrode.
1 . A light receiving element comprising:
a substrate;
a first electrode metal formed on a top surface of the substrate;
a semiconductor layer bonded to a top surface of the first electrode metal; and
a second electrode metal formed on a top surface of the semiconductor layer, wherein
the semiconductor layer includes
a first semiconductor contact layer in contact with the first electrode metal,
a second semiconductor contact layer in contact with the second electrode metal, and
a semiconductor absorbing layer between the first semiconductor contact layer and the second semiconductor contact layer, and
the first electrode metal has an extraction path for propagating a signal to an anode electrode or a cathode electrode.
2 . The light receiving element according to claim 1 , further comprising an antireflection film formed on the second semiconductor contact layer.
3 . The light receiving element according to claim 1 , wherein the first electrode metal includes gold having a thickness of at least 30 nm.
4 . The light receiving element according to claim 1 , further comprising:
a first electrode pad connected to the first electrode metal; and
a second electrode pad connected to the second electrode metal, wherein
the first electrode pad and the second electrode pad are formed at positions where a distance between top surfaces of the first electrode pad and the second electrode pad and the top surface of the substrate is smaller than a distance between a top surface of the second semiconductor contact layer and the top surface of the substrate.
5 . The light receiving element according to claim 1 , further comprising:
a first electrode pad connected to the first electrode metal; and
a second electrode pad connected to the second electrode metal, wherein
the first electrode pad and the second electrode pad are formed at positions where a distance between undersurfaces of the first electrode pad and the second electrode pad and the top surface of the substrate is smaller than a distance between a top surface of the second semiconductor contact layer and the top surface of the substrate.
6 . The light receiving element according to claim 1 , wherein the first semiconductor contact layer includes a selectively doped region.