Semiconductor photo-detector

Abstract

Abstract PURPOSE: To reduce the diffusion process while eliminating any guard ring by making the thickness at the center of the epitaxial layer positioned under the pn- junction less than those in other parts in the formation of the junction on the layer grown on a semiconductor substrate. CONSTITUTION: An n-type InP substrate 9 is projected only at the center by a mesa etching while a layer 10 of n-type InGaAsP or InGaAs is allowed to grow epitaxially on the entire surface. Then, a p-type region 3 is formed in the layer 10 by diffusion or ion injection corresponding to the projected area and a pn-junction is produced on the interface with the layer 10. Otherwise, in stead of the mesa etching of the substrate 9, the center of the epitaxial layer 10 may be etched deep. Then, the entire substrate is covered with an inductive material layer 7 and a window is given on the region 3, where an electrode terminal T 1 is mounted extending over the film 7 while an terminal T 2 is mounted on the back of the substrate 9 through an electrode 2. This reduces dark current and the junction capacity, making the device ideal for avalanche photo diodes very small in the light detecting diameter. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Yoshihisa Yamamoto
• 👤 Hiroaki Ando
• 👤 Hiroshi Kanbe

Bibliographic Details