| 摘要 |
PURPOSE:To decrease junction capacitance and to improve breakdown strength at the junction, by narrowing a channel region, and forming a gate electrode by a self-aligning method. CONSTITUTION:A thermal oxide film 2 is formed on a semiconductor substrate 1. After a silicon nitride film 7 is deposited, an opening is formed by a photomask step and an etching step. A silicon oxide film 8 is deposited on the film 7 and the opening. Then the film 8 is etched so that the film 8 is made to remain only at the sidepart of the film 7 on the side of the opening. Then boron is implanted for forming a channel, and a channel region 3 is formed. Thereafter, the film 8 is removed by wet etching. Thereafter, a thermal oxide film 2' is deposited, and polysilicon is deposited thereon. The layer 7 is released, and a gate electrode 4 is formed. Since the region 3 can be made narrow and deviation from the electrode 4 does not occur, the junction capacitance is decreased, and the breakdown strength at the junction is improved.
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