| 摘要 |
PROBLEM TO BE SOLVED: To make a gate electrode width narrow for attempting minimization by forming the gate electrode made of poly-silicon by a resist pattern having an exposure limit size width by using an i beam light source, by oxidizing up to a predetermined depth from the surface and by eliminating an oxidized region. SOLUTION: A silicon oxide film 2 and a poly-silicon film 3 are formed by laminating on a semiconductor substrate 1. A resist mask 4 is formed on the poly-silicon film 3 and this is imagined as a minimum width by an i beam exposure device, for example a pattern of 0.365μm. Next the poly-silicon film 3 is eliminated by etching and a required film thickness is made to remain. Next the semiconductor 1 is entered in oxygen atmosphere to be heated and the poly-silicon film 3 is oxidized from the surface side. In the case oxidation is made from the poly-silicon film 3 remained while the etching to reach the silicon oxide film 2 and an oxide region 7 having a required film thickness is formed on the whole surface. After that all the oxidized region 7 is eliminated by etching.
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