| 摘要 |
PURPOSE:To make a lower part of polycrystalline silicon low in resistance so as to prevent a standby current from increasing in an SRAM by a method wherein impurity ions are implanted in an interface between the high-resistance polycrystalline silicon of a SRAM and an SiO2 film under it. CONSTITUTION:An oxide film (HTO film) 22 is formed through a CVD method, and a non-doped polycrystalline silicon film 28 is formed through a vacuum CVD method. Then, oxygen ions are implanted in an interface between the non-doped polycrystalline silicon film 28 and the insulating film 22 in dose of 1X10<19>cm<-2> with an accelerating energy of 70KeV by a large current ion implanting device. A large amount of interstitial silicon is generated in an interface between the non-doped polycrystalline silicon film 28 and the insulting film 22 by annealing carried out at a temperature of 90 deg.C and in an N2 atmosphree, and the lower part of the non-doped polycrystalline silicon film 28 becomes high in resistance. |
