| 摘要 |
PURPOSE:To improve sensitivity, and to lower noises extremely by forming the multi-periodic layer structure of the mixed-crystal semiconductors of Si, Ge and Sn onto an Si semiconductor substrate and laminating a lattice mismatching relaxing layer consisting of Si and Ge and an Si semiconductor layer onto the multi-periodic structure. CONSTITUTION:A p-Si buffer layer 2, a p-Si1-x-yGaxSny/Si1-x'-y'Gex'Sny' multi- periodic layer 3 laminated at fifty periods at periods of at every thickness such as 100Angstrom , a p-Si1-zGez lattice mismatching relaxing layer 3', and p-Si 4 are laminated onto a p<+> Si substrate 1 in predetermined thickness. Beams are projected through SiO2 6 at that time, and optically pumped carriers are generated in the multi-periodic layer 3. Only electrons in carriers generated are transferred up to an n<+>-p junction, and avalanche multiplication is generated. Quantum efficiency is acquired by 60-70% at the specific wavelength of the hetero- structure APD while the ratio of the ionization rate beta of holes to the ionization rate alpha of electrons displays an excellent value such as 0.03-0.05. O<x, y<1, 0<=x' and y'<1 hold in formula. |
