| abstract |
In a semiconductor integrated circuit, a plurality of thin filmntransistors (TFTs) are formed on the same substrate having anninsulating surface. Since gate electrodes formed in the TFTs arenelectrically insulated each other, voltages are appliednindependently to gate electrodes in an electrolytic solution duringnan anodization, to form an anodic oxide in at least both sides ofneach gate electrode. A thickness of the anodic oxide is changed innaccordance with characteristics of the TFT. A width of highnresistance regions formed in an active layer of each TFT is changednby ion doping using the anodic oxide having a desired thickness asna mask. |