▎ 摘　　要

NOVELTY - The method involves forming a grid electrode by an oxidation graphene. A grate insulation layer is formed in the oxidation graphene, which is composed with a source electrode and a drain electrode. A source rod is fixed with the drain electrode. A grid electrode is formed in the oxidation graphene, which is doped with a graphene active area for forming the oxidation graphene. A first oxidation graphene material layer is formed in the grid electrode. A second oxidation graphene material layer is formed in the grate insulation layer. USE - Thin film transistor preparation method. ADVANTAGE - The method enables avoiding performance problem of a thin film transistor. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a thin film transistor. DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of a thin film transistor.