| 摘要 |
PURPOSE: A method for fabricating a semiconductor device is provided to form thin film transistor(TFT) structures optimal for driving conditions of a pixel portion and driving circuits by using a small number of photo masks. CONSTITUTION: The first, second and third semiconductor films are formed on the first insulation film. The first, second and third electrodes(116,117,118) of the first shape are formed on the first, second and third semiconductor films. The first, second and third electrodes of the first shape are used as masks in the first doping treatment to form the first concentration impurity regions of one conductivity type in the first, second and third semiconductor films. The first, second and third electrode of the second shape are formed from the first, second and third electrodes of the first shape. The second concentration impurity region of the one conductivity type which overlaps the second electrode of the second shape is formed in the second semiconductor film in the second doping treatment. The third concentration impurity regions of the one conductivity type which are placed in the first and second semiconductor films are formed in the second doping treatment. The fourth and fifth concentration impurity regions having the other conductivity type that is opposite to the one conductivity type are formed in the third semiconductor film in the third doping treatment. |
