| 摘要 |
PURPOSE:To improve dark current, junction capacitance and photo-electric conversion efficiency by laminating semiconductor layer considering the forbidden energy band width and impurity concentration thickness. CONSTITUTION:The n-InP 12 in the thickness of 1.5mum and the In1-xGaxAsyPy-1 14 with the thickness of 1.3mum and narrow forbidden energy band width which will becomes the active region are stacked on the n<+>-InP substrate 11. Here, it is intended to increase light sensitivity by selecting x and y in such a relation that 0.47>=x>=0.25, y=x(0.48043+0.00327x)<-1>. Moreover, as the window layer, the n- InP 14 with wide forbidden energy band width and thickness of 1.8mum and the n-In1-xGaxAsyP1-y 15 of 0.2mum are stacked, the surface is covered with the SiO2 and an aperture is opened to the layer 15, and the Cd is diffused to the layer 14, thereby the p<+> layer 16 in the depth of 0.7mum, reflection preventing film 17', surface protection film 17 and electrodes 18, 19 are formed. According to this structure, the characteristic of layer interface is stabilized and a dark current is decreased. A high performance photo semiconductor device can be obtained by setting the impurity concentrations of layers 13 and 14 as follow, N14>=N13, N<=2X10<16>cm<-2>. |
