POLYCRYSTALLINE SILICON THIN FILM TRANSISTOR AND MANUFACTURE THEREOF

PURPOSE:To improve characteristics by preparing a polycrystalline silicon TFT for deposition of a silicon nitride film and by forming a dense silicon oxide film with a smaller number of pin holes than that of the silicon nitride film for hydrogenation. CONSTITUTION:A polycrystalline silicon film 2 is deposited on a quartz substrate 1 by pressure-reduced CVD and etched in an island form. The next step is heat treatment in a nitride atmosphere after formation of a gate oxide film 3 by thermal oxidation. After polycrystalline silicon is deposited, a gate electrode 4 is formed by etching. A further step is to form source-drain regions 2-1, 2-2 with a mask of the gate electrode 4 and to form the interlayer insulating film 5 consisting of SiO2 film by thermal oxidation upon activation of impurity ions. This interlayer insulating film 5 is opened for contact windows, and Al wiring layers 6 are formed and sintered. The final step is deposition of a silicon nitride film 7 by plasma CVD and to hydrogenation after deposition of an SiO2 film 8 with a smaller number of pin holes by ozone CVD. This process can improve characteristics without escapes of hydrogen atoms during hydrogenation.