Semiconductor photodetector device and manufacturing method therefor
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorEitaro Ishimura
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Abstract
A laminated structure including an InGaAs light absorption layer and an InP window layer on a n-type InP substrate. A p-type diffusion layer region is formed in an InP window layer. A depletion layer between the n-type InP substrate and the p-type diffusion layer region is formed when a voltage is applied between a cathode electrode and an anode electrode. The depletion layer is thicker in at least a portion of a region under the anode electrode than in a light detecting portion. In this case, the diffusion depth of the p-type diffusion layer region may be smaller in at least the portion of the region under the anode electrode than in the light detecting portion.
Claims8
A semiconductor photodetector device comprising:
- a substrate;
- a laminated structure on said substrate, said laminated structure including a semiconductor layer of a first conductivity type, a light absorption layer, and a window layer;
- an impurity region of a second conductivity type in said window layer;
- a first electrode for energizing said semiconductor layer of the first conductivity type;
- and
- a second electrode for energizing said impurity region of said the second conductivity type, wherein a depletion layer between said semiconductor layer of the first conductivity type and said impurity region of the second conductivity type is thicker in at least a portion of a region under said second electrode than in a region for absorbing incident light, the depletion layer being formed when a voltage is applied between said first and second electrodes.
A method for manufacturing a semiconductor photodetector device having a laminated structure which includes a semiconductor layer of a first conductivity type, a light absorption layer, and a window layer, said method comprising
- introducing an impurity producing a second conductivity type into a predetermined region of said window layer to form a guard ring region;
- after forming said guard ring region, introducing another impurity producing the second conductivity type into said window layer to form a shallow impurity region of the second conductivity type inside said guard ring region;
- and
- after forming said shallow impurity region of the second conductivity type, further introducing another impurity producing the second conductivity type into said window layer to form a deep impurity region of the second conductivity type on the inner side of said shallow impurity region of said second conductivity type.
Dependencies are inferred from the claim text.