| 摘要 |
PROBLEM TO BE SOLVED: To obtain a semiconductor device in which a gate electrode and a gate insulating film in different film thicknesses and of different materials are formed on an identical substrate, by a method wherein a first film and a second film are removed from at least one region out of a plurality of regions in which gate electrodes are formed, and a first insulating film and a first gate electrode are formed in the region from which the films are removed. SOLUTION: A well region and an element isolation region are formed on a silicon substrate 201. A gate oxide film 203 is formed, and a poly-Si film 204 is formed on it. In a region in which a first transistor is formed mainly, the poly-Si film 204 is removed by a heated phosphoric acid solution. In succession, the gate oxide film 203 in an exposed region is removed by a dilute hydrofluoric acid solution. A gate oxide film 211 is formed on the surface of the silicon substrate 201 in the exposed region, and a tungsten film 212 is formed additionally on the whole face. In a first element region, a first gate electrode is constituted of the poly-Si film 204. In a second element region, a second gate electrode is constituted of the tungsten film 212. |
