SEMICONDUCTOR PHOTODETECTOR

摘要

PURPOSE:To provide a higher speed and higher efficiency by setting the carrier concn. in the region of a clad layer lower than the carrier concn. in the region of a core layer. CONSTITUTION:An n-InP substrate 1 is the lower clad layer. An n-In0.53Ga0.47As layer 2 and an p<+>-In0.53Ga0.47As layer 3 are the core layer. A p-InP layer 4 is the upper clad layer. The photodetector is formed by epitaxially growing the respective layers, then working the layers to a waveguide structure by etching and forming a p type ohmic electrode 6 on the p-InP layer and an n type ohmic electrode 5 on the rear surface of the InP substrate, respectively by vapor deposition. The carrier concn. in the region of the clad layer 4 is set lower than the carrier concn. in the region of the core layer 3 in this case. The absorption of the light in the clad layer is, therefore, sufficiently suppressed. The higher speed and the higher photoelectric conversion efficiency are obtd. in this way.