Yuzhu, It may worth to take a look at this paper about a plasma/wet combined Cu etch... Yours sincerely, Isaac Chan, Ph.D. University of Waterloo On Wed, 24 Aug 2005, Yuzhu Li wrote: > > Hi, anyone know a copper wet etch that gives small side etch? need to > etch about 1um copper but need to control sideetch: several micron's > sideetch is not acceptble...