LIQUID CRYSTAL DISPLAY DEVICE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a liquid crystal display device almost free from spot defects without deteriorating the TFT characteristics of a peripheral driving circuit by making projections formed on the surface of a polycrystal silicon layer in an auxiliary capacity part lower than those formed on the surface of a polycrystal silicon layer in a thin film transistor. SOLUTION: An undercoat 12 is formed on a glass substrate 11 and an amorphous silicon film 13 is deposited on the undercoat 12. The top of the amorphous silicon film 13 in a region for TFT is coated with a resist 200 and the amorphous silicon film 13 in a region for an auxiliary capacity part is plasma-etched to 35-43 nm thickness. The thickness of the amorphous silicon in the auxiliary capacity part is made smaller than that in the TFT part, the silicon in the auxiliary capacity part is converted into a fine polycrystal body and the occurrence of projections is very effectively suppressed. The objective liquid crystal display device having high pressure resistance and a small leakage current and almost free from spot defects is obtained.