JPS5451788A - Photoelectric transducer - Google Patents

Abstract

PURPOSE: To increase the conversion efficiency with decreased crosstalk, by forming the photoelectric transducer on the electric insulator substrate with the substrate used as the cap for enclosure of the transducer and then reducing the distance between the fiber end surface and the surface of the photoelectric transducer down to the substrate thickness.

CONSTITUTION: P^--layer 71 of Si and p-active layer 2 are formed on sapphire substrate 70, and n^--diffusion layer 1 is provided to form Ti-gold electrode 3 selectively. The mesa-etching is given via mask 3, and electrode 4 is formed selectively after isolation of the Si layer. When the chip of the photo detector is mounted to package 30 through the above structure, substrate 1 can be used directly as the cover. And the distance between the fiber end surface and the light receiving surface of the transducer can be reduced down to the substrate thickness, thus increasing the photoelectric conversion efficiency as well as decreasing the crosstalk. At the same time, the Si lamination layer is sufficiently thin, and the mesa-etching is possible from the Si layer side. Thus, an easy mesa-etching can be given with the back electrode used directly as the mask even though the active layer may be thick

COPYRIGHT: (C)1979,JPO&Japio