METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To improve the reliability of a semiconductor device by making a substrate made of a plastic, etc., having a low heat resistance usable by forming the gate insulating film of a TFT without raising the temperature of the substrate and constituting the device in such a structure that further improves the S-value of the TFT and reduces off-leakage currents. SOLUTION: At the time of forming the gate insulating film, an insulating film is formed by the sputtering method so that the film may contain a region having a hydrogen concentration of 0.4-1.6 atomic % when the hydrogen concentration of the film is measured by the HFS (hydrogen forward scattering) analysis method. Then another insulating film is formed on the insulating film by the sputtering method so that the film may contain a region having a hydrogen concentration of <=0.2 atomic % when the hydrogen concentration of the film is measured by the HFS analysis method. When the TFT is manufactured by using the structure of this gate insulating film, such a TFT characteristic is obtained that is low in sub-threshold coefficient and suppresses the occurrence of leakage currents between a gate electrode and a source electrode or a drain electrode.