| 摘要 |
PURPOSE:To obtain preferable characteristics and high reliability by forming a semidconductor photodetector made of the first conductive type semiconductor layer and a semiconductor layer of the second conductive type opposite to the first conductive type in a recess of conical trapezoid formed in a semi-insulating substrate. CONSTITUTION:In case of an InP-InGaAs APD, an N<+> type InP buffer layer 22, an N type InGaAs photoabsorbing layer 23, an N type InP layer 24, and a P<+>-InP layer 25 are formed in a recess of conical trapezoid or a mesa-shaped recess formed on a semi-insulating substrate 21, the substrate 21 is then formed with an N type side electrode 28 on the back surface side, a P type electrode is formed from above the layer 25, a surface protective film 26 is formed to complete an element. For example, the back surface of the growing wafer is formed in a thickness of 150-200mum, the back surface is photolithographically and chemically etched until reaching the layer 22, an AuGeNi is deposited on the entire back surface in contact with the layer 22 to form an N type side electrode 28. |
