| 摘要 |
PURPOSE:To obtain the photo-receiving element of high sensitivity and high speed for the titled transistor by a method wherein an N-layer and a P-layer, having the same composition, and an N-layer having the forbiden band width wider than that of the above N-layer are laminated on the prescribed semiconductor substrate, a mesa form reaching the junction surface of the first and the second layers is provided, and the area of the absorption layer only is increased. CONSTITUTION:An N-InP layer 32, an N<->-In0.57Ga0.43As layer 33, a P<+>-In0.57 Ga0.43As layer 34 and an N<->-InP layer 35 are epitaxially formed in vapor phase on an N-InP substrate 31, a mesa etching is performed as deep as to the junction surface of the layers 33, 34, and an Si3N4 reflection film 38 is formed on the exposed layer 33. The substrate and layers 32 and 33 constitute a collector, the layer 34 constitutes a P<+> base and the layer 35 constitutes an N-emitter. A beam of light is made incident from the circular window of the back side electrode 37 on the substrate 31, and the collector and base are used by having them inversely biased. According to this constitution, the depletion layer with which holes are supplied to the base by absorbing light spread almost all over the layer 33, and the efficiency of a reflection film 38 is increased by having double the thickness of its absorption region. According to this constitution, the coupling loss is small even when the incident luminous flux has a large area, and a photo-receiving element of high speed and high photoelectric current multiplication factor can be obtained. |
