Patent ID: 7378325
Filing Date: 2008-05-27
Classification: H01L

Abstract:
1. A manufacturing method of manufacturing a semiconductor device comprising: a collector region of a first conduction type; an emitter region of the first conduction type; and a base region of a second conduction type opposite to the first conduction type located between the collector region and the emitter region, wherein the free carrier density of the base region where no depletion layer is formed is smaller than the space charge density of a depletion layer formed in the base region, the manufacturing method comprising: forming the base region by use of a first impurity of a second conduction type which serves to generate an impurity level with a predetermined depth from the edge of the band gap of a base semiconductor material of the semiconductor device while the free carrier density is smaller than the space charge density by a predetermined value, wherein the base region is formed by semiconductor epitaxial growth with the first impurity as a dopant.