| 摘要 |
PURPOSE:To improve the reverse withstand voltage of a laminated diode, and to stabilize electrical characteristics by forming a semiconductor element while using an Si crystal as a substrate, doping Pt and thermally treating the whole at a specific temperature. CONSTITUTION:The p<+>-n-n<+> diode is constituted while using an n type Si wafer as the substrate (spreading resistance (Rs):1.4X10<4>OMEGA), Pt is diffused and treated, and the whole is thermally treated in N2 gas of 90mm. at 700 deg.C. The spreading resistance Rs of an n type base layer under an emitter P<+> layer is -1.7X10<4>OMEGA after Pt is diffused, but it increases to -3.0X10<4>OMEGA through heat treatment. Accordingly, only withstand voltage up to one of 650V per one pellet is obtained through the conventional methods, but withstand voltage is increased up to one of 900V per one pellet through the method. Substrate resistance changes remarkably within a range of a temperature of 650 deg.C-850 deg.C. |
