| 摘要 |
PURPOSE:To improve the reliability by forming a material capable of sublimating by varying a pattern to an oxide, thermally oxidizing the pattern to partly sublimate and remove it, and reducing the size in channel direction, thereby avoiding the concentration of an electric field in source, drain and channel regions without damaging the surface of a substrate. CONSTITUTION:Phosphorus ions are, for example, implanted on a substrate 21 with a CVD-SiO2 film pattern 24 as a mask, and high density impurity layers 25, 26 are formed. Further, a heat treatment is performed in an oxidative atmosphere, the exposed surface of a pattern 24 made of Mo is oxidized to alter into MoO3, and to sublimate it. Thus, the size of the pattern 24 in the channel direction (lateral direction) is reduced as a gate electrode 24'. Then, a CVD-SiO2 pattern is removed with ammonium fluoride, phosphorus ions are, for example, implanted to the substrate 21 with the gate electrode 24' as a mask, and low density n type impurity layers 27, 28 are formed. |
