P‐5.6: Analysis of ITO Residue in 4mask process applied in Extra large‐size FFS LCDs

Indium tin oxide (ITO) residue is a serious problem in 4mask process applied in Fringe Field Switching (FFS) mode LCDs. In this paper, we analyzed the composition and structure of the residues and the reasons for their formation. ITO grains grow with increasing temperature during copper sputtering. As a result, it is hardly etched in the subsequent wet etching process, resulting in residues.