Process Techniques of 15-inch Full-Color High-Resolution Liquid Crystal Displays Addressed by a-Si Thin Film Transistors

Abstract

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 SiO 2 /TaO x /SiN x /(i/n + )a-Si and a-Si/Ti, respectively. Fine patterning and easier stepcoverage of subsequently deposited layers are achieved.