Patent ID: 9466751
Filing Date: 2016-10-11
CPC Classification: H01L,Y02E

Claim Text:
1. A photodetector device, comprising a p-type ohmic contact layer, said p-type ohmic contact layer being a first p+-type doped semiconductor; an n-type ohmic contact layer, said n-type ohmic contact layer being a second n a window layer, said window layer being a third p+-type doped semiconductor, said window layer being located between said p-type ohmic contact layer and said n-type ohmic contact layer; a first graded bandgap layer, said first graded bandgap layer being a fourth p+ type doped semiconductor, said first graded bandgap layer being located between said window layer and said n-type ohmic contact layer; a first absorption layer, said first absorption layer being a fifth p− type doped semiconductor, said first absorption layer being located between said first graded bandgap layer and said n-type ohmic contact layer; a second absorption layer, said second absorption layer being a sixth undoped semiconductor, said second absorption layer being located between said first absorption layer and said n-type ohmic contact layer; a second graded bandgap layer, said second graded bandgap layer being a seventh undoped semiconductor, said second graded bandgap layer being located between said second absorption layer and said n-type ohmic contact layer; a field buffer layer, said field buffer layer being an eighth undoped semiconductor, said field buffer layer being located between said second graded bandgap layer and said n-type ohmic contact layer; a first p-type field control layer, said first p-type field control layer being a ninth p−-type doped semiconductor, said first p-type field control layer being located between said field buffer layer and said n-type ohmic contact layer; a multiplication layer, said multiplication layer being a tenth undoped semiconductor, said multiplication layer being located between said first p-type field control layer and said n-type ohmic contact layer; and an n-type contact layer, said n-type contact layer being an eleventh n wherein the n-side multiplication-layer down photodetector device has a first mesa between said first absorption layer and said second absorption layer and a second mesa between said second graded bandgap layer and said field buffer layer to confine the electric field inside the photodetector device by said first mesa and said second mesa.