Composition for etching metal films

Abstract

The present invention relates to a composition for etching metal films, and more specifically, to an etchant composition comprising an oxidant, an etching controller, a chelating agent, an undercut inhibitor, a copper corrosion inhibitor, a residue remover and the balance of water, for collectively wet etching metal films used as a gate electrode and a data electrode within a thin film transistor for a flat display, particularly, a single-layered film or a multilayered film consisting of one or more materials selected from copper, molybdenum, titanium and a molybdenum-titanium alloy. The composition of the present invention inhibits the rapid reaction of an oxidant and a copper ion when applied to an etching process through the use of a novel chelating agent, thereby providing an etchant with excellent lifetime and stability, an etched metal film with a gentle slope angle, suitable control of CD loss, and a good etching profile inhibiting the residue of a lower molybdenum, titanium or molybdenum-titanium alloy film. In addition, if a volatilization inhibitor is further added, precipitate and foreign matter generation is greatly reduced in etching equipment, and thus it is possible to improve productivity with respect to etching equipment operation and to reduce failure rates.

Description

technical field [0001] The invention relates to a metal film for etching gate electrodes and data electrodes of thin film transistors used as flat panel displays by batch wet etching, in particular comprising a metal film selected from copper, molybdenum, titanium and molybdenum-titanium alloys or a combination of single or multilayer films. Background technique [0002] Thin film transistors are obtained by forming metal lines on a substrate. In general, a metal film is formed by physical adsorption, followed by patterning by exposure using a photoresist and etching to prepare a patterned thin film. Among them, the etching process is a process in which a metal film is selectively etched according to a pattern formed in an exposure process. [0003] Since a thin film transistor liquid crystal display having better performance is required, a metal film having low resistance to fast driving is required. In order to meet this requirement, metal materials such as copper and s...

AI Technical Summary

Problems solved by technology

Although many improvements have been achieved regarding residue and stability issues, deposition in etch setups is still a problem

Images