| CPC G01J 1/4228 (2013.01) [G01J 2001/4466 (2013.01)] | 8 Claims |
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1. A semiconductor avalanche photodiode for light detection, the avalanche photodiode comprising:
a p-n junction comprising a first shallow extrinsic semiconductor layer with a first type of doping embedded in a second well-shaped extrinsic semiconductor layer with a second type of doping opposite to the first type of doping;
a first electric contact configured to electrically connect the first semiconductor layer;
a second electric contact configured to electrically connect the second semiconductor layer;
an avalanche region at the interface between the two semiconductor layers configured to undergo avalanche breakdown when triggered by the light to be detected; and
a dielectric isolation trench extending into the second well-shaped semiconductor layer and surrounding an outer periphery of the avalanche region to prevent premature edge breakdown in the avalanche photodiode;
wherein the isolation trench is arranged, in a radial direction, in-between the first electric contact and the second electric contact;
wherein:
the isolation trench comprises an encasement made of a dielectric material and a metallic core surrounded by the dielectric encasement; and
the thickness of the isolation trench is greater than or equal to 90% of the thickness of the second well-shaped semiconductor layer, the isolation trench thus forming a deep trench isolation within the second well-shaped semiconductor layer.
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