BIPOLAR INTEGRATED CIRCUIT DEVICE AND ITS MANUFACTURE

摘要

PURPOSE:To shorten a bird-beak, and to improve the degree of integration by using a thin oxide film as a collector-contact isolation region isolating a collector-contact section and a base region. CONSTITUTION:With a semiconductor layer 3 on a semiconductor matrix 100, a side surface is isolated electrically by a thick oxide film 4 and a bottom by a PN junction between a buried layer 2 and a semiconductor substrate 1 respectively. A bipolar transistor with an N<+> type emitter region 7, a P type base region 8 and an N type collector region 9 from the surface is formed in an isolated element forming region 6, and an ohmic-contact is executed to the region 9 through the N<+> type collector-contact section 10. The collector-contact isolation region 11 of a boundary section between the section 10 and the region 9 is constituted by the oxide film through the selective oxidation of the matrix 100 in the same manner as the region 4, and the thickness is made thinner than the oxide film 4 up to thickness through which only a misfit dislocation is prevented. The length of the bird-beak through selective oxidation can be shortened by thinning the thickness of the oxide film to be formed.