| 摘要 |
PURPOSE:To reduce parasitic capacitance among a gate and both a source and a drain, and to improve high-frequency characteristics by coating the surface of the gate consisting of polycrystalline Si with an Si3N4 film, changing the side surface section of the gate into an oxide film while using Si3N4 as a mask and shortening gate length when the gate is formed to a semiconductor device such as an MOSFET. CONSTITUTION:The surface of an Si substrate 11 is coated with a thin oxide film, holes are bored made correspond to a source and a drain, and a gate oxide film 12 is formed through re-oxidation. A predetermined gate pattern consisting of a polycrystalline Si film 13 and an Si3N4 film 14 is formed on the film 12, ions are implanted while using the gate pattern as a mask, and a drain region 15 and a source region 16 are formed in the substrate 11 on both sides of the pattern and activated through heat treatment. Only the side surface sections of the film 13 are changed into oxide films 17 while using the film 14 as a mask, and the gate length of the film 13 as a gate is shortened. When an impurity is doped previously into the film 13 at that time, the films 17 are easily formed. |
