| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid crystal display device, where the electrical characteristics of a transistor with polysilicon as an active layer is reduced. SOLUTION: After a barrier layer 2 consisting of a SiO2 film and a silicon nitride film is formed on a glass substrate 1, an impurity with an amount corresponding to the threshold voltage of an n-channel type TFT is added, and a CVD is made, thus forming an amorphous silicon layer 3. Then, the silicon nitride film is formed on the upper surface of substrate and the upper surface of the substrate is polished and patterning is made, then an impurity with an amount corresponding to the threshold voltage of a p-channel type TFT is added and CVD is made, an amorphous silicon layer 5 is formed, and polishing is made until the amorphous silicon layer 5 is exposed. Then, the amorphous silicon layers 3 and 5 are crystallized, polysilicon layers 6 and 7 are formed through laser annealing, and a TFT is formed with the layers 6 and 7 as active layers. Since the channel region of the TFT is formed by the CVD, the fluctuations in the threshold of the TFT is reduced.</p> |
