| 摘要 |
PURPOSE:To obtain the semiconductor device of Darlington structure, having a built-in Zener diode which is used to obtain stabilized performance characteristics, without increasing the area occupied by circuits by a method wherein the junction located between the collector region formed in a high density impurity region and a base region is operated as a Zener diode. CONSTITUTION:An N type collector region 2 is formed on an N type substrate 1 using an epitaxial growing method, and an N type region 3 of the impurity density higher than that of the region 2 is formed on said region 2 by performing an ion-implanting method. Then, base region 4 of P type conductivity and an emitter region 5 of N type conductivity are formed using a selective diffusion method, an SiO2 film is selectively removed and an electrode layer 7 is formed, thereby enabling to obtain a Darlington transistor. A Zener diode D2 is connected in-between the base of a driving transistor Tr1 and the collector of output transistor Tr2, and it is incorporated in the same chip. When the breakdown voltage of the Zener diode is set at the desired voltage, it is operated as a protective diode against the surge voltage applied between collector bases or between emitters. |
