| 摘要 |
PURPOSE:To reduce a drain leakage current by a method wherein a semiconductor film is grown on an insulation substrate, and the neighborhood of the interface of said film is changed into an insulator by Si and N ion implantation thereto contacting the substrate and heat treatment. CONSTITUTION:An Si film 22 is epitaxially grown on the sapphire substrate 21. Next, Si and N are ion-implanted to the film 22. C can be used instead of N. Further, an Si3N4 film 24 are deposited by a CVD method. Then, patterns 25 and 26 are formed by patterning films 24 and 23. A field oxide film 27 is formed at the etched part of the Si film 22, and a gate oxide film 29 is formed on an island form Si film 28 by removing the patterns 25 and 26. An insulation layer 30 is formed by heat treatment. A p type impurity is implanting through the film 29, and a gate electrode 31 is formed by depositing an Si film. An n type impurity is implanted, thus forming the source and drain regions 32 and 33. |
