| 摘要 |
PURPOSE:To form a p-well region and an n-well region in a self-alignment manner while preventing the generation of the stepped difference of the surface of a substrate by removing a pattern and a material layer section to be oxidized under the pattern and implanting the ions of a second conduction type impurity. CONSTITUTION:A thermal oxide film 12 is grown onto the n type single crystalline silicon substrate 11, and a polycrystalline silicon layer 13 and a silicon nitride film are deposited onto the whole surface in succession. The ions of boron as a p type impurity are implanted while using the resist pattern 14 as a mask. The ions of phosphorus as the n type impurity are implanted, and an n type ion implanted region 18 is formed into the substrate 11. The whole is treated at a high temperature, each ion implanted region 16, 18 is driven in, and the p-well region 19 and the n-well region 20 are formed to the surface of the n type single crystalline silicon substrate 11. |
