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US4982255A
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Avalanche photodiode
Assignee: NEC Corp
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Filing: 1989-11-17
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Granted: 1991-01-01
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Expires: 2009-11-17
Abstract
Abstract An avalanche photodiode comprises an electron multiplication layer of superlattice including InAlAs mixed crystal layers which are lattice-matched with InP, and InGaAsP mixed crystal which are lattice-matched with InP and are provided with a bandgap energy of 1.0 eV to 1.2 eV at the room temperature. In the electron multiplication, a conduction band discontinuity is much greater than a valence band discontinuity to increase a ratio between ion densities α and β for electron and hole, so that a noise level is decreased and a response characteristic is improved.
Inventors
- 👤 Akihisa Tomita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:33
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/225; H10F30/2255
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
An avalanche photodiode, comprising: a substrate of InP; a light absorption layer for generating carriers provided over said substrate; an electron multiplication layer for realizing an avalanche multiplication provided over said substrate; and n- and p-electrodes for applying a predetermined voltage across said substrate, said light absorption layer, and said electron multiplication layer; wherein said electron multiplication layer is a superlattice structure and includes a predetermined number InAlAs mixed crystal layers which are lattice-matched InP and a predetermined number of InGaAsP mixed crystal layers which are lattice-matched with InP, said InGaAsP mixed crystal layers having a bandgap energy of 1.0 eV to 1.2 eV at room temperature.
Claim 2
Dependent Claim
107 words
An avalanche photodiode, comprising: a substrate of InP; a light absorption layer for generating carriers provided over said substrate; an electron multiplication layer for realizing an avalanche multiplication provided over said substrate; and n- and p-electrodes for applying a predetermined voltage across said substrate, said light absorption layer, and said electron multiplication layer; wherein said electron multiplication layer is a superlattice structure and includes a predetermined number InAlAs mixed crystal layers which are lattice-matched InP and a predetermined number of InGaAsP mixed crystal layers which are lattice-matched with InP, said InGaAsP mixed crystal layers having a bandgap energy of 1.0 eV to 1.2 eV at room temperature.
Claim 3
Dependent Claim
158 words
An avalanche photodiode, comprising: a substrate of InP; a buffer layer provided on said substrate; a light absorption layer for generating carriers provided on said buffer layer; an electron multiplication layer having different bandgap energies for realizing an avalanche multiplication provided on said light absorption layer, each bandgap energy of said electron multiplication layer being larger than a bandgap energy of said light absorption layer; a window layer provided on said electron multiplication layer; P-electrode provided on a surface of said substrate opposite to said buffer layer; and n-electrode provided on a surface of said window layer opposite to said multiplication layer; wherein said electron multiplication layer is a superlattice structure and includes a predetermined number of InAlAs mixed crystal layers which are lattice-matched in InP and a predetermined number of InGaAsP mixed crystal layers which are lattice-matched with InP, said InGaAsP mixed crystal layers having a bandgap energy of 1.0 eV to 1.2 eV at room temperature.
Claim 4
Dependent Claim
158 words
An avalanche photodiode, comprising: a substrate of InP; a buffer layer provided on said substrate; a light absorption layer for generating carriers provided on said buffer layer; an electron multiplication layer having different bandgap energies for realizing an avalanche multiplication provided on said light absorption layer, each bandgap energy of said electron multiplication layer being larger than a bandgap energy of said light absorption layer; a window layer provided on said electron multiplication layer; P-electrode provided on a surface of said substrate opposite to said buffer layer; and n-electrode provided on a surface of said window layer opposite to said multiplication layer; wherein said electron multiplication layer is a superlattice structure and includes a predetermined number of InAlAs mixed crystal layers which are lattice-matched in InP and a predetermined number of InGaAsP mixed crystal layers which are lattice-matched with InP, said InGaAsP mixed crystal layers having a bandgap energy of 1.0 eV to 1.2 eV at room temperature.
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