MANUFACTURE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE:To improve the breakdown strength of an insulating film by a method wherein a polycrystalline silicon film (in phosphorus concentration exceeding 5X10<20>cm<-3>) is deposited using a unsingle crystal silicon film wherein the adsorption points of silicon atoms are distributed in high concentration as a primer layer. CONSTITUTION:A unsingle crystal silicon film 53 in phosphorus concentration of zero or not exceeding 5X10<20>cm<-3> is formed at the reaction temperature of 400 deg.C-600 deg.C on the first insulating film 52 on the main surface of a semiconductor substrate 51; successively a polycrystalline silicon film 54 in phosphorus concentration exceeding 5X10<20>cm<-3> is formed on the silicon film 53; and then another polycrystalline silicon film 55 in phosphorus concentration of zero or not exceeding 5X10<20>cm<-3> is formed. Finally, the second insulating film 56 is formed on the silicon film 55. Through these procedures, the diffusion of phosphorus in the insulating film 52 can be reduced to improve the breakdown strength in combination with the film denseness.