| 摘要 |
PURPOSE:To increase a backward current mu-factor of IIL element without decreasing a withstand voltage of a high withstand voltage element by a method wherein the base region junction depths of the high withstand voltage element and the IIL element are made different from each other. CONSTITUTION:A buried N<+>-diffused region 22 is formed on the surface of a P type semiconductor substrate 21, and an N<-> layer 23 is grown by a vapor growth method on the region 22. Then, a buried N<->-diffused region 24 is formed and further, an N<-> layer 25 is formed by the vapor growth. A P<+>-isolation diffused region 27 is diffused until reaching the P type semiconductor substrate 1. Subsequently, the base region 30 of the high withstand voltage element is formed by diffusion simultaneously with an injector region 28 and base region 29 of the IIL element by a long time heat treatment and diffused deeply. Then, N<+>-regin 32 for taking out a collector electrode, emitter N<+>-region 31 of the high withstand voltage element, an N<+>-region 34 for taking out earth electrode, and collector N<+>-region 33 of the IIL element are formed by the same diffusion. Thereby, the high withstand voltage analog element and the IIL element are simultaneously formed on the same substrate. |
