| 摘要 |
PURPOSE:To form an element whose resistance is lower than a tungsten or molybdenum polycide LDD type MOS transistor, by a method wherein, after polycrystalline silicon is deposited, only said polycrystalline silicon is selectively wet-etched, and metal is selectively deposited only on the surface of polycrystalline silicon after the etching. CONSTITUTION:In the case of manufacturing a semiconductor device having a MOS field-effect transistor whose gate electrode has a lamination structure of a lower part polycrystalline silicon layer 38 and an upper part metal layer 35, polycrystalline silicon 34 is deposited, and then only the polycrystalline silicon 34 is selectively wet-etched. Only on the surface of the polycrystalline silicon 34 after the etching, metal 35 is selectively deposited. For example, after a polycrystalline Si gate LDD type MOS transistor is formed by an ordinary method, a gate electrode 34 is etched to be 2000Angstrom thick by using etching agent whose main component is ethylenediamine-pyrocatechol. An Al layer 35 is deposited on the surface of the polycrystalline Si 34, by a chemical vapor deposition method using alkyl aluminum hydride and hydrogen. |
