| 摘要 |
PURPOSE:To enable to finish the device whose junction depth of a high concentration graft base has not so much difference as compared with junction depth of an intrinsic base, and to prevent the device from increase of junction capacitance between the base and a collector, etc., by a method wherein a mask is selected as to act as the mask to ion implantation when an emitter layer is to be formed, but as not to act as the mask against ion implantation when the base layer is to be formed. CONSTITUTION:An SiO2 film 2 is formed on an Si substrate 1, and after on Si3N4 film 3 is formed thereon, the Si3N4 film 3 at the emitter forming region 4 is etched to be removed using dry etching technique. Ion implantation is performed in succession under the condition that the accelerating voltage is 30keV, the dose is 5X10<15>cm<-2> using As<+> as the source, and an annealing treatment is applied at 950 deg.C for 20min to activate As ions 5. Then ion implantation is performed under the condition that the accelerating voltage is 25keV, the dose is 1X10<14>cm<-2> using B<+> as the source in the condition of the same mask structure to form base junctions 6, 7. After then an annealing treatment is performed at 900 deg.C for 10min. |
