US Patent 9059045 Semiconductor device and manufacturing method thereof

A TFT is manufactured using at least five photomasks in a conventional liquid crystal display device, and therefore the manufacturing cost is high. By performing the formation of the pixel electrode 127, the source region 123 and the drain region 124 by using three photomasks in three photolithography steps, a liquid crystal display device prepared with a pixel TFT portion, having a reverse stagger type n-channel TFT, and a storage capacitor can be realized, FIG. 2.