Semiconductor light-receiving element

• US 6,303,968 B1
• Filed: 01/24/2000
• Issued: 10/16/2001
• Est. Priority Date: 08/26/1999
• Status: Expired due to Term

• Current Assignee: NeoPhotonics Corporation (Lumentum Holdings Inc.)
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Kobayashi, Takanobu
• Primary Examiner(s): Meier, Stephen D.
• Application Number:
  US09/490,327
• Time in Patent Office: 631 Days
• Field of Search: 257/435, 257/448, 257/452, 257/457
• US Class Current: 257/435
• CPC Class Codes: H01L 31/022408 for devices characterised by at least one potential jump barrier or surface barrier
• CPC Class Codes: H01L 31/1035 the devices comprising active layers formed only by AIIIBV compounds
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells

Abstract

An ohmic electrode for electrically connecting a shielding metal film and a window layer is provided to a semiconductor light-receiving element in which stray light is controlled by the shielding metal film. In this semiconductor light-receiving element, the ohmic electrode is disposed such that it encircles a p⁺ diffusion region while kept in contact with the window layer on a substrate. Crack propagation from the edgewise region into the ohmic electrode is thereby impeded.

Claims

1. A semiconductor light-receiving element, comprising:

a light-absorbing layer of a first conduction type and a window layer of the first conduction type, sequentially formed on the first principal surface of a substrate of the first conduction type;

a diffusion region of a second conduction type, provided to part of said window layer and extended as far as the boundary between said window layer and said light-absorbing layer; and

a shielding film cladding, formed on said window layer around said diffusion region;

wherein said shielding film cladding is constructed by cladding a shielding metal film and an insulating film;

said shielding metal film is part of said shielding film cladding and is electrically connected to said window layer by means of an ohmic electrode; and

said ohmic electrode is provided so as to encircle said diffusion region while in contact with said window layer.

2. A semiconductor light-receiving element according to claim 1, wherein said substrate is an indium/phosphorus-based substrate.

3. A semiconductor light-receiving element according to claim 1, wherein a connection electrode is further provided for electrically connecting said ohmic electrode and said shielding metal film.

4. A semiconductor light-receiving element according to claim 3, wherein said diffusion region is provided with a first main electrode in contact with said diffusion region, and said connection electrode and said first main electrode are formed from the same electroconductive material.

5. A semiconductor light-receiving element according to claim 1, wherein said ohmic electrode is provided in the edgewise region of said substrate along the external periphery of said substrate.

6. A semiconductor light-receiving element according to claim 1, wherein the second principal surface of said substrate is provided with a second main electrode.

7. A semiconductor light-receiving element according to claim 1, wherein said substrate is an InP substrate, said light-absorbing layer is an InGaAs layer, and said window layer is an InP layer.

8. A semiconductor light-receiving element according to claim 7, wherein an InP buffer layer is provided between said InP substrate and said InGaAs layer.

9. A semiconductor light-receiving element according to claim 1, wherein part of said diffusion region functions as a light-receiving surface, and an antireflection film is formed on said light-receiving surface.

10. A semiconductor light-receiving element according to claim 9, wherein the light-nonreceiving surface of said diffusion region is provided with a first main electrode in contact with said diffusion region.

11. A semiconductor light-receiving element according to claim 10, wherein said light-receiving surface is shaped as a circular flat pattern, and said light-nonreceiving surface is configured as a crescent-shaped flat pattern adjacent to said light-receiving surface within the same plane.

12. A semiconductor light-receiving element according to claim 1, wherein a silicon nitride film is used as said insulating film.

13. A semiconductor light-receiving element according to claim 3, wherein said ohmic electrode is formed from an alloy of gold (Au) and zinc (Zn) if said connection electrode is formed from gold (Au).

14. A semiconductor light-receiving element according to claim 1, wherein said shielding metal film is formed from titanium (Ti) or molybdenum (Mo).

15. A semiconductor light-receiving element according to claim 1, wherein said ohmic electrode is electrically connected to said window layer at a position farther away from said diffusion region than the width of a depletion layer formed around said diffusion region.

16. A semiconductor light-receiving element according to claim 1, wherein said diffusion region is provided with a first main electrode in contact with said diffusion region, a discontinuous section is provided to a curvilinear pattern obtained by forming an electrode pattern from said ohmic electrode, and said discontinuous section is disposed at the closest position to said first main electrode.