| 摘要 |
PURPOSE:To improve the characteristics of a thin film transistor by forming a source/drain regions made of a high concentration polycrystalline silicon layer formed on the gate insulating film of a transparent substrate and an amorphous silicon layer on the insulating film, and annealing the lower layer of the amorphous silicon layer by a short wave laser from the rear surface. CONSTITUTION:A transparent electrode 11 is formed on a quartz substrate 1, etched with a predetermined mask, and a gate insulating film 3 is formed thereon. Then, a polycrystalline silicon layer (DOPOS) 12 doped with an impurity is formed in high concentration by a reduced pressure CVD method. Further, it is coated with liquidlike substance mixed with SiO2 powder to form an SiO2 film 13. After it is etched to become flat by a dry etching method, the DOPOS 12 is etched so that the DOPOS 12 remains on the source, drain regions. Thereafter, an amorphous silicon layer 7 is formed, and the channel region of the layer 7 is annealed from the rear surface. Then, an insulating film 8 is formed, opened to form electrodes 9, 10. Thus, the number of the masks can be reduced without deteriorating the performance of a transistor. |
