| 摘要 |
PURPOSE:To reduce avalanche noises largely by joining an indirect transition type semiconductor with a light absorption layer in a light-receptor for a long wavelength band using only a direct transition type compound semiconductor and multiplying carriers in an avalanche manner in the indirect transition type semiconductor. CONSTITUTION:In0.53Ga0.47As lattice-aligned in approximately 3mum is grown on an InP substrate 4 having p type impurity concentration in approximately 10<15>cm<-3>, and the light absorption layer 1 is formed. p Type impurity concentration in the layer 1 is brought to approximately 5X10<15>cm<-3> so that the layer 1 is changed into a depletion layer on operation for operation at high speed. AlAs0.4Sb0.6 2 having the same lattice constant as the substrate is grown similarly, and a p-n junction is formed in the layer 2. The thickness of the p type AlAs0.4 Sb0.6 layer requires width sufficient for generating an avalanche multiplication and shall be values to several mum from several thousand Angstrom , and impurity concentration in the layer shall be approximately 7X10<15>cm<-3>. Electrons in electron-hole pairs generated in the light absorption layer 1 are injected into an avalanche region 3. Avalanche noises generated additionally are reduced extremely because secondary electron-hole pairs are generated preferentially by an electron bombardment in the region 3. |
