| 摘要 |
PURPOSE:To provide a fine MOS type semiconductor device having a gate electrode with the width of 1mum or less, by forming an MOS element at a stepped portion provided on an Si substrate. CONSTITUTION:A type Si substrate 6 is provided with a stepped portion and SiO2 1 is formed thereon by thermal oxidation. W is deposited by chemical vapor deposition and then the W deposited on the flat portions is removed without any mask of photoresist or the like by reactive ion etching with the use of SF. Consequently, an electrode 2 having a triangular cross section with the base of (a) is obtained at the stepped portion. As<+> ions are implanted with the electrode 2 used as a mask to form diffused layers 3, 4 and 5. While the electrode has the very small width of (a), the channel length (b) practically obtained is substantially longer than that width. Accordingly, the device can be fined with little variation in the characteristics which would be caused due to a shorter channel length. Further, both N<+> and N<-> type layers can be formed simultaneously with a single process of ion implantation, the characteristics of the elements during operation can be stabilized. |
