| 摘要 |
PURPOSE:To form a semiconductor device with high reliability for a long time under the severe radioactive environment by a method wherein fluorine is contained in an insulating film formed on a semiconductor substrate. CONSTITUTION:Element isolating silicon oxide films 105b containing fluorine are formed on overall surface of substrate 1 by means of ion-implanting 106 the surface with silicon tetrafluoride. At this time, the ion-implanting energy is arbitrarily set up in terms of the film thickness of element isolating silicon oxide film 105b, a silicon oxide film 102 and a silicon nitride film 103 not to implant the silicon substrate 101 with needless fluorine. Moreover, the silicon nitride film 103 and silicon oxide films 4 on the element regions of silicon substrate 101 are removed removed to ion-implant the overall surface of silicon substrate 101 again with silicon tetrafluoride amounting to around 3X10<15>cm<-2>. At this time, the ion-implanting energy is restircted to around 20keV or less to reduce any damage due to ion-implantation in the element regions while it is recommanded to implant the element regions with ion obliquely. |
