A semiconductor device including a first semiconductor chip, a second
semiconductor chip bonded to the first semiconductor chip in a stacked
relation, and a registration structure which causes the first and second
semiconductor chips to be positioned with respect to each other by
depression-projection engagement therebetween. The registration structure
includes, for example, a registration recess provided on a surface of the
first semiconductor chip, and a registration projection provided on a
surface of the second semiconductor chip for engagement with the
registration recess. The registration projection may be a spherical
member provided on the surface of the second semiconductor chip.