hi. I heard about Cu could be patterned by something like CMP Process ( damascene(?) process) Are there any wet etchants fot Cu etch? If not, what is the main reason about that? Furthermore, Adhesion layer (Ti or Cr) is not required when I deposit Cu on Si Wafer ? Thank you for in Advance. TW Lee. ----------------------------------------------------------- AeroMEMS Laboratory. School of Mechanical & Aerospace Engineering. Seoul National University , Seoul , KOREA.