Patent ID: 6798001
Filing Date: 2004-09-28
Classification: H01L

Abstract:
A semiconductor device having a photo diode comprising:a first conductivity type first semiconductor layer; a first conductivity type second semiconductor layer disposed on said first conductivity type first semiconductor layer; and a second conductivity type semiconductor layer formed at a surface layer portion of said first conductivity type second semiconductor layer; wherein said first conductivity type first semiconductor layer comprises a surface impurity concentration greater than that of said first conductivity type second semiconductor layer; and wherein when an inverse bias of a predetermined amount is applied to a junction of said first conductivity type second semiconductor layer and said second conductivity type semiconductor layer, a depletion layer is spread to a region between a first predetermined amount and a second predetermined amount in a depth direction from a surface of said second conductivity type semiconductor layer, such that a sensitivity of said photo diode to light of a first wavelength and a sensitivity of light of second wavelength, which is different from said first wavelength, are made substantially the same.