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US 6,724,063 B2Granted
Photodiode and photodiode module
AssigneeSumitomo Electric Industries, Ltd.
InventorsYoshiki Kuhara, Hitoshi Terauchi
Life of this patent
Estimating the term…
Abstract
Besides the central pn-junction and the central electrode, a PD chip has a peripheral pn-junction and a peripheral electrode which do not appear on the sides. The ends of the peripheral pn-junction are covered with a protection layer for preventing self-shortcircuit. A reverse bias is applied to the peripheral electrode for making a wide depletion layer beneath the peripheral pn-junction. Extra carriers generated by peripherally-incidence rays are fully absorbed by the peripheral depletion layer and annihilated by the reverse bias.
Claims6
A photodiode comprising:
- an n-type semiconductor substrate;
- an n-type light receiving layer epitaxially grown on the n-type substrate;
- a central p-region produced at a center of the light receiving layer by diffusing a p-type dopant;
- a central pn-junction intervening between the central p-region and the n-type light receiving layer and having a ring end;
- a diffusion-shield p-region being made by diffusing a p-type dopant in a ring region enclosing the central p-region with an outermost part of the n-type light receiving layer left undoped;
- a ring peripheral pn-junction intervening between the diffusion-shield p-region and the n-type light receiving layer and having ring ends;
- a signal p-electrode formed upon the central p-region;
- a diffusion shield p-electrode formed upon the peripheral ring diffusion-shield p-region;
- and
- a protecting film covering the end of the central pn-junction and the ends of the peripheral diffusion-shield pn-junctions,
- wherein the diffusion shield p-region is a circular ring region, the diffusion-shield p-electrode is a circular ring and the diffusion-shield pn-junction is a circular ring having ends concentrically enclosing the diffusion-shield p-region.
8 more elements
A photodiode comprising:
- an n-type semiconductor substrate;
- an n-type light receiving layer epitaxially grown on the n-type substrate;
- a central p-region produced at a center of the light receiving layer by diffusing a p-type dopant;
- a central pn-junction intervening between the central p-region and the n-type light receiving layer and having a ring end;
- a diffusion-shield p-region being made by diffusing a p-type dopant in a ring region enclosing the central p-region with an outermost part of the n-type light receiving layer left undoped;
- a ring peripheral pn-junction intervening between the diffusion-shield p-region and the n-type light receiving layer and having ring ends;
- a signal p-electrode formed upon the central p-region;
- a diffusion shield p-electrode formed upon the peripheral ring diffusion-shield p-region;
- and
- a protecting film covering the end of the central pn-junction and the ends of the peripheral diffusion-shield pn-junctions,
- wherein the diffusion shield p-region is a square ring region, the diffusion-shield p-electrode is a square ring and the diffusion-shield pn-junction is a square ring having ends enclosing the diffusion-shield p-region.
8 more elements
A photodiode comprising:
- an n-type semiconductor substrate;
- an n-type light receiving layer epitaxially grown on the n-type substrate;
- a central p-region produced at a center of the light receiving layer by diffusing a p-type dopant;
- a central pn-junction intervening between the central p-region and the n-type light receiving layer and having a ring end;
- a diffusion-shield p-region being made by diffusing a p-type dopant in a ring region enclosing the central p-region with an outermost part of the n-type light receiving layer left undoped;
- a ring peripheral pn-junction intervening between the diffusion-shield p-region and the n-type light receiving layer and having ring ends;
- a signal p-electrode formed upon the central p-region;
- a diffusion shield p-electrode formed upon the peripheral ring diffusion-shield p-region;
- and
- a protecting film covering the end of the central pn-junction and the ends of the peripheral diffusion-shield pn-junctions,
- wherein the diffusion shield p-region is an elliptical ring region, the diffusion-shield p-electrode is an elliptical ring and the diffusion-shield pn-junction is an elliptical ring having ends enclosing the diffusion-shield p-region.
8 more elements
Dependencies are inferred from the claim text.