Semiconductor integrated circuit device with self-aligned superhigh

Abstract

A superhigh speed vertical transistor having an ultra thin base, a vertical NPN transistor having a reverse direction structure for composing an IIL, and a lateral PNP transistor similarly composing an IIL to be an injector are formed on a P-type silicon substrate 1 by self-aligned and integrated. The emitter leading-out part opening of the superhigh speed vertical NPN transistor and the collector leading-out part opening of the vertical NPN transistor having a reverse direction structure are self-aligned to the base leading-out electrode. In the epitaxial layer, the P-type intrinsic base layer of superhigh speed vertical NPN transistor is formed by impurity diffusion from the emitter leading-out electrode formed of polysilicon film, and the P-type base layer of the vertical NPN transistor having a reverse direction structure is formed by ion implantation. By thus forming the superhigh speed vertical NPN transistor having a reverse direction structure in self-aligned process, the superhigh speed vertical NPN transistor of self-aligned type and IIL device may be integrated on a same chip. Besides, by forming the intrinsic base layer of the vertical NPN transistor having a reverse direction structure deeper in junction than the base layer formed by impurity diffusion from the polysilicon emitter electrode for the superhigh speed NPN transistor of self-aligned type, the low concentration epitaxial layer part beneath the intrinsic base layer for composing the emitter of the vertical NPN transistor having a reverse direction structure may be made smaller, thereby avoiding lowering of the current gain of the vertical NPN transistor having a reverse direction structure and lowering of high speed operation of IIL device accompanying accumulation of minority carrier.