| 摘要 |
PURPOSE:To contrive low noises by preventing the generation of leakage current due to a P-N junction by a method wherein the graft base region of high impurity density and the emitter region of high impurity density are formed so as not to be directly contacted with each other. CONSTITUTION:A substrate 1 is heated in an oxygen atmosphere, then one conductivity type impurity contained in a film becomes the diffusion source, and accordingly the graft base 5 is formed at the fixed position of a semiconductor layer. An insulation film 8 is formed in a part of the base 5, then one conductivity type impurity ions are ion-implanted via an aperture part 33 and heat- treated, and thus an active base 6 is formed. The other conductivity type impurity ions are implanted via the part 33 and heat-treated, and accordingly the emitter 7 is formed. Since the base 5 and the emitter 7 are not directly contacted with each other in this manner, the generation of leakage current due to a P- N junction can be prevented, and therefore low noises can be contrived. |
