SEMICONDUCTOR DEVICE AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To make it possible to form a high-frequency transistor having small parasitic collector resistance and a highly dielectric transistor on the same substrate even if the substrate has a thick epitaxial layer. SOLUTION: A second reverse-conductivity buried collector layer 22 is formed which is raised up from a first reverse-conductivity buried collector layer 21. A reverse-conductivity pedestal collector layer 102 and a first conductivity base layer 8 are formed at the position contacting the second reverse- conductivity buried collector layer 22. This can prevent a Kirk effect to thereby increase the film thickness of an epitaxial collector layer.