| 摘要 |
PURPOSE:To prevent the generation of tunnel currents at an operating time by interposing a semiconductor intermediate layer, which has forbidden band width is larger than both an optical absorption layer and a multiplication layer and is lattice-matched with both layers, between both layers. CONSTITUTION:An N-AlInAs layer 3 as a three-element semiconductor layer is inserted between an N-GaInAs layer 2 as an optical absorption layer and an N-InP layer 4 as a multiplication layer on an N<+>-InP substrate in high concentration. DELTAEV takes approximately 0.2eV in both hetero-junction sections among InP/AlInAs and AlInAs/GaInAs though the layer having large forbidden band width EG is inserted to an intermediate section, the storage effect of holes on the hetero-interfaces can be reduced sufficiently, and holes can be moved smoothly, thus acquiring response at high speed. Since the N-AlInAs layer as an intermediate layer 3 has large forbidden band width, tunnel currents can be minimized. Accordingly, the generation of tunnel currents under operating voltage can be prevented. |
