Patent ID: 8039918

Claim:
A semiconductor photo detector, having a layer structure comprising: a layer of a first-type conductivity; a light absorption layer of a second-type conductivity; a selective etching layer of the second-type conductivity; a buffer layer of the second-type conductivity; a contact layer of the second-type conductivity; and an electrode in the side of the second-type conductivity, which are sequentially deposited over a semiconductor substrate, and having a second mesa formed on said semiconductor substrate and a first mesa formed on said second mesa, wherein said first mesa includes said buffer layer of the second-type conductivity, said contact layer of the second-type conductivity, and said electrode in the side of the second-type conductivity, wherein said second mesa includes an outer periphery located outside of the outer periphery of said first mesa in two-dimensional view, and a second mesa semiconductor staked structure including said layer of the first-type conductivity, said light absorption layer of the second-type conductivity, said selective etching layer of the second-type conductivity, and a hydrogen passivation region, wherein at least a side surface of said second mesa semiconductor staked structure is covered with a passivation film, and wherein said hydrogen passivation region is formed from a surface of said second mesa semiconductor staked structure toward an inside of said second mesa semiconductor staked structure.