JPS6446969A - Photodetector - Google Patents

Abstract

PURPOSE:To make the mutual insulation between elements formed on a dielectric isolation substrate perfect, and making the elements suitable to detect light in a long wavelength region like infrared rays, by forming an element constituting a circuit part linked to a photodetector part on the surface of at least one isolation island, and connecting said circuit part and the photodetector part on the substrate surface. CONSTITUTION:In isolation islands 11, 12 on a dielectric isolation substrate 1 having a plurality of isolation islands 11, 12 insulating-layer-isolated, a photodetector part PD1 is arranged, which is constituted of a P-N junction in a manner in which layers 11b, 12b with different polarity to the isolation islands are arranged so as to reach the surface from the bottom surface passing through the side surface along the insulating layer 1b. On the surface of at least one isolation island 12, an element T1 constituting a circuit part linked to the photodetector part PD1 is formed. This circuit part and the photodetector part PD1 are connected on the substrate surface. Thereby, the insulation between elements formed on the dielectric isolation substrate 1 is made perfect. Further, the photodetector element part PD1 is formed on the bottom part of the isolation island 11, and is made suitable to detect light in a long wavelength region such as infrared rays.