HANDOTAIHIKARIKENSHUTSUKI

摘要

PURPOSE:To reduce low noise characteristic and low dark current characteristic in a semiconductor photodetector by forming an avalanche acceleration layer of superlattice configuration and forming a P-N junction in a thin film layer made of gallium and arsenic forming the superlattice configuration. CONSTITUTION:A superlattice configuration 11 formed by laminating more than 25 layers of thin film layers made of N type Ge and thin film layers made of GaAs is formed on the surface of a GaAs crystalline substrate 10. The uppermost layer of the configuration 11 is made of a GaAs thin film layer. A GaAs crystalline layer 13 of P type surrounded by a guard ring layer 12 is formed on the predetermined region of the GaAs thin layer of the configuration 11. A P type electrode 15 connected to the layer 13 is formed on an insulating layer 14 formed on the exposed surface of the uppermost thin film layer and the layer 12. Then, an N type electrode 6 is formed on the back surface of the substrate 10.