Photo-sensing device
AssigneeSumitomo Electric Industries, Ltd.
InventorYasushi Fujimura
Life of this patent
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Abstract
A region of a second conductivity type is selectively formed in a portion of a semiconductive layer of a first conductivity type to form a pn junction area which serves as a photo-sensing region. A metal film is formed on a surface of the semiconductive layer of the first conductivity type to surround the photo-sensing region. When light to be directed to the photo-sensing region spreads outside the photo-sensing region, the light is reflected by the metal film provided on the surface of the semiconductive crystal layer around the photo-sensing region. Accordingly, the light does not reach the photo-sensing layer of the semiconductive crystal layer and the generation of undesired carriers is prevented.
Claims9
A photo-sensing device comprising:
- a heavily doped semiconductor substrate of a first conductivity type:
- a lightly doped semiconductor layer of said first conductivity type, said lightly doped semiconductor layer being formed on said heavily doped semiconductor substrate;
- a heavily doped region of a second conductivity type provided in a portion of said lightly doped semiconductor layer, said heavily doped region and said semiconductor layer forming a p-n junction which provides a photo-sensing region;
- an insulating layer formed directly on said lightly doped semiconductor layer and around said heavily doped region;
- an electrode contacting said heavily doped region at a main surface thereof;
- and
- a metal layer formed on said insulating layer, said metal layer also contacting said lightly doped semiconductor layer.
A photo-sensing device comprising:
- a heavily doped semiconductor substrate of a first conductivity type:
- a lightly doped semiconductor layer of said first conductivity type, said lightly doped semiconductor layer being formed on said heavily doped semiconductor substrate;
- a heavily doped region of a second conductivity type provided in a portion of said lightly doped semiconductor layer, said heavily doped region and said semiconductor layer forming a p-n junction which provides a photo-sensing region, said heavily doped region having a main surface at an upper surface thereof;
- an insulating layer formed directly on said lightly doped semiconductor and around said heavily doped region;
- an electrode having a first portion which contacts said heavily doped region of said second conductivity type, and a second portion which extends from said first portion onto an upper surface of said insulating layer to beyond an edge of said heavily doped region in the direction of said main surface of said heavily doped region;
- and
- a metal layer formed over said lightly doped semiconductor layer on said insulating layer.
Dependencies are inferred from the claim text.