Patent ID: 7820971

Claim:
A detector of incident radiation in the infrared region, comprising: a first semiconductor layer highly doped to be of a first conductivity type, a conductive common contact made to the first semiconductor layer; a second semiconductor layer formed on a face the first semiconductor layer and doped to be of the first conductivity type, the second semiconductor layer having a predetermined first spectral response with respect to the wavelength of incident radiation; a third semiconductor layer formed on the second semiconductor layer to be opposite the first semiconductor layer and doped to be of the first conductivity type, a contact portion of the third semiconductor layer highly doped to be of a second conductivity type opposite the first conductivity type, the third semiconductor layer having a first surface adjoining the second semiconductor layer and a second surface opposed to the first surface, said contact portion extending from the first surface to the second surface, a conductive first detector contact formed on the second surface of the third semiconductor layer within said contact portion; a fourth semiconductor layer having a first surface adjacent the second surface of the third semiconductor layer and a second surface opposed to the last said first surface, the fourth semiconductor layer formed to be of the first conductivity type and formed on a portion of the third semiconductor layer so as to spaced from the contact portion of the third semiconductor layer, the fourth semiconductor layer having a predetermined second spectral response with respect to the wavelength of incident radiation which is substantially different from the first spectral response; and a fifth semiconductor layer having a first surface adjacent the second surface of the fourth semiconductor layer and a second surface opposed the last said first surface, the fifth semiconductor layer formed to be of the second conductivity type, a conductive second detector contact formed on the second surface of the fifth semiconductor layer.