PURPOSE: To eliminate a gap, to overlap a semiconductor substrate and to facilitate an external heat dissipation by forming a joining part on the side face of a principal plane containing an active region of a semiconductor substrate.

CONSTITUTION: Numeral 1 shows a semiconductor substrate. Numeral 2 shows a PN joining region and an active region containing a wiring part formed thereon. Numeral 3 shows a joining part for putting out and in an electrical signal outside from said active region 2. Numeral 9 shows a filler for a heat dissipation and an adhesion between respective semiconductor substrate 1. As the joining part 3 is formed on the side face of the principal plane containing the active region 2, it is possible to overlap the semiconductor substrate in a plural number and obtain a higher integrated circuit and the semiconductor device containing an IC with a suitable heat dissipation.