| 摘要 |
PURPOSE:To manufacture a transistor in excellent reproducibility by forming an epitaxial layer with a profile, impurity concentration thereof close to a semiconductor substrate is made lower, onto the substrate and inplanting the ions of an impurity having a reverse conduction type to the epitaxial layer. CONSTITUTION:The N type epitaxial layer 12 is shaped onto the N type Si substrate 11 through a LPE method or a MBE method. In this case, the impurity profile of the epitaxial layer 12 is set so that impurity concentration is made lower at the substrate 11 side and higher in the surface. The surface of the epitaxial layer 12 is coated with a thick oxide film 13 and a thin oxide film 15, and the ions of the P type impurity such as B are inplanted. Energy injected at that time is adjusted so that the peak of the concentration of B is formed at the position of predetermined depth of the epitaxial layer 12 in a region not masked with the oxide films 13, 15. Accordingly, the base region 16 of the transistor is shaped, and a residual region 17 functions as an emitter. The transistor having stable characteristics can be manufactured because the impurity can easily be controlled in both the epitaxial layer 12 and the ion implanted layer 16. |
