SIGE PHOTODIODE

摘要

Provided is a SiGe photodiode that has high incident photon-to-current conversion efficiency and has superior operating characteristics at high frequencies. A SiGe photodiode (100) is provided with: a P-type semiconductor layer (102) having a first region (102a) and a second region (102b) located below the first region (102a); an I-type semiconductor layer (103) formed on the first region (102a) of the P-type semiconductor layer (102); and an N-type semiconductor layer (104) formed on the I-type semiconductor layer (103). The concentration of impurities in the first region (102a) is lower than that in the second region (102b).