Optical sensor and photodiode
AssigneePixart Imaging Inc.
InventorYu-Wei Wang
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Abstract
A photodiode, comprising: a first photodiode, comprising a p type substrate and a signal output region; a positive electric field providing structure, provided in the P type substrate, configured to receive a positive voltage to provide a positive electric field according to the positive voltage to attract electrons in the P type substrate; wherein an avalanche region is formed when the positive voltage is larger than a threshold voltage, thereby a current path is formed between the signal output region and the positive electric field providing structure. The present invention also discloses an optical sensor comprising pixels with different light sensitivities.
Claims2
A photodiode, comprising:
- a p type substrate;
- a first P doped region, provided in the p type substrate, served as a signal output region for outputting a light sensing signal;
- a first N doped region, provided in the p type substrate, for receiving a positive voltage;
- a second P doped region, provided in the P type substrate, below the first P doped region and the first N doped region;
- wherein an avalanche region is formed between the second P doped region and the first N doped region when the positive voltage is larger than a threshold voltage;
- wherein the photodiode further comprising:
- a second N doped region below the second P doped region, wherein the second N doped region is used for collecting electrons;
- a first N well provided in the P type substrate and next to the first P doped region and the second N doped region;
- and
- a first P well provided in the P type substrate and next to the first N well.
Dependencies are inferred from the claim text.