| 摘要 |
PURPOSE:To obtain the side wall of a gate electrode stably with excellent reproducibility by executing ion implantation and annealing to depositing poly Si and etching the poly Si in a solution type. CONSTITUTION:An element isolation region 2 by an oxide film and a gate oxide film 3 are formed on a P type Si single crystal substrate 1, and a gate electrode 4 consisting of poly Si is shaped on the film 3. The surface of the electrode 4 is coated with an oxide film 5. Phosphorus ions are implanted to form ion implanting layers 7. Poly Si is deposited on the whole surface. The ions of an impurity such as arsenic are implanted 9 onto the poly Si layer 8 in the quantity of dose of 1X10<15>cm<-2> or more. The substrate 1 is annealed after the implantation 9. A poly Si layer into which arsenic is not diffused remains on the side wall of the electrode 4 at that time. When the surface is etched in a solution type, a side wall 11 by poly Si is shaped because there is a large difference in etching rates according to the presence of the diffusion of arsenic. Consequently, the side wall 11 of the electrode 4 is formed stably without damaging source-drain regions. |
