Method for producing a transistor using anodic oxidation

摘要

A method for producing a thin-film transistor (TFT) in which the gate electrode is offset from the source and drain without detriment to the characteristics of the device or to manufacturing yield, and a structure for such a TFT, are disclosed. A gate electrode is formed using a material capable of anodic oxidation, and a mask is formed on the gate electrode. Using a comparatively low voltage, a comparatively thick, porous anodic oxide film is formed on the sides of the gate electrode. The mask is then removed and using a comparatively high voltage a dense anodic oxide film is formed at least on the top of the gate electrode. Using the gate electrode having this anodic oxide on its top and sides as a mask, an impurity is introduced into the semiconductor film and an offset structure is obtained.