| 摘要 |
PURPOSE:To speed up the operation and improve the dielectric strength of a junction by a method wherein a mask material is left on the side wall of an oxidization-resistant film pattern by anisotropic ion etching and impurity ions are implanted into a substrate to form an inversion-preventing high impurity concentration region and an element isolation region is formed by selective oxidization. CONSTITUTION:A silicon nitride film pattern 22 and an oxide film pattern 23 are formed on a P type silicon substrate 21. A CVD SiO2 film 24 is deposited and etched by anisotropic etching so as to remain only on the side wall of the silicon nitride film pattern 22. Then, utilizing the pattern 22 and the remaining film 24 as a mask, boron ions are implanted to form P<+> type field inversion preventing layers 25 and the CVD SiO2 film 24 is removed by etching. By forming field oxide film 26, element regions 27 are isolated from each other. After the oxide film pattern 23 is removed, a gate oxide film 28 is formed and a polycrystalline silicon layer 29 is deposited and patterned to form a gate electrode 30. Utilizing the gate electrode 30 as a mask, ions are implanted into the element region 27 to form N<+> type source and drain regions 31 and 32. |
