| abstract |
(57) Abstract: A method for etching a metal layer for etching a metal layer provided on a substrate of a semiconductor device or the like to obtain a connection terminal having a sufficient bonding strength with an external terminal, for example. To aim. SOLUTION: A silicon wafer 10 on which a bump electrode 16 made of gold is formed is placed in a vacuum device, and reactive ion gas is introduced to generate plasma, whereby gold that is a surface of the bump electrode 16 and an underlayer. The thin film 16a is etched. As the reactive ion gas, CF 4 , C 2 F 6 , C 3 At least one halogenated gas selected from F 8 , CHF 3 and SF 6 , and CF 3 Cl, CF 2 Cl 2 and CFC By using a mixed gas of at least one chlorine-based gas selected from l 3 , HCl, and CCl 4 , the gold thin film 16a is removed, and the fine deep V-shaped groove is formed on the surface of the bump electrode 16. Is formed. By bonding the bonding agent into the V-shaped groove of the bump electrode during bonding with the external terminal, the bonding strength is improved. |