-- Etching solution for Molybdenum-Aluminum alloy-Molybdenum metal layer

摘要

PURPOSE: An etchant for etching a tri-layered metallic film of Mo/Al-Nd/Mo is provided, which can etch the tri-layered metallic film of Mo/Al-Nd/Mo without undercut phenomenon of a bottom Mo layer while forming a metal line of a TFT-LCD. CONSTITUTION: A tri-layered metallic film of Mo/Al-Nd/Mo is used as a source/drain array metal line. And the etchant includes H3PO4 of 68-74 wt%, HNO3 of 2-4 wt%, CH3COOH of 5-15wt% and water. And the etchant also includes an additive of 0.01-0.l05 wt% of the whole composition. The etchant also includes H3PO4 of 70-74 wt%, HNO3 of 2-4 wt%, CH3COOH of 8-15wt%, water and an additive of 0.01-0.03 wt%. The water is an ultra pure water having a resistance above 18M ohm.