| 摘要 |
PURPOSE:To form a controlled conductive layer with good repeatability in which ion is implanted by a method wherein after impurity ion is implanted in deep region and thereafter annealing is performed at high temperature and for long hours, then residual impurity inside section or surface side of a substrate crystal is subjected to gettering to crystal defect, ion for forming a conductive layer is implanted to thereon. CONSTITUTION:Boron is implanted deeply into a high resist GaAs substrate 11. At this time, highest concentration position of boron is designated to about 0.6mum from the surface, and its density is designated to about 3X10<17>cm<-3>. Subsequently, after SiO2 film is adhered to the surface, heat-treatment is performed at 600 deg.C for 10hrs. in H2 atmosphere. At this time, impurity such as Cr, C, Si and the like of inside and surface side of crystal substrate 11 is deffused forward to injury portion generated by ion implantation and is seized. Next, after SiO2 film 12 is removed <28>Si<+> ion is implanted so as to form a conductive layer. The SiO2 film 15 is adhered again, and anneal is performed at 800 deg.C for 20min in H2 atmosphere, thereafter, the SiO2 film is removed. By this fact, in disregard of impurity concentration in the substrate crystal, a controlled conductive layer in which ion is implanted can be formed with good repeatability. |
