Low Temperature Deposition of Gate Silicon Dioxide Film for Thin Film Transistors by Photoassisted Remote Plasma Chemical Vapor Deposition Method

Abstract

High quality silicon dioxide films with low leakage current and low surface charge density were deposited by a photoassisted remote plasma chemical vapor deposition (PAP-CVD) method at 330° C. Oxygen gas excited in a plasma which is kept apart from the wafer, was transported to the wafer and reacted with monosilane gas to generate intermediates. The adsorbed intermediates on the wafer were photoexcited to produce silicon dioxide films. Since the energy and the flux of incident ions to the wafer are suppressed to be as low as 1.4 eV and 1.3×1013 cm-2 s-1, respectively, high-quality films with low leakage current and low surface charge density were successfully deposited at low temperature. The silicon dioxide film fabricated by the PAP-CVD method is suitable for use as the gate insulator of a thin film transistor (TFT).