Process techniques of 15-inch full-color high-resolution liquid crystal displays addressed by a-Si thin film transistors

A 15 inch-diagonal-size full-color liquid crystal display (LCD) with 1152(×3)×900 pixels has been fabricated which enables a portable workstation with improved display performances. The process techniques used for this development are described, with special reference to metallization and dry etching. In multilevel metallization, Cr/Al interconnection is metallurgically undesirable. By contrast, the Cr/Ti/Al metal system provides excellent properties of contact resistivity and thermodynamical stability. Dry etching processes are developed for multilayered insulating films and metallization-related bilayers, namely SiO2/TaOx/SiNx/(i/n+)a-Si and a-Si/Ti, respectively. Fine patterning and easier stepcoverage of subsequently deposited layers are achieved.