[mems-talk] Any metal can not be etched by TMAH and BOE (buffered oxide etchant, mainly HF)?

[jian zi]

Dear everyone,
   
  Recently, I want to sputter a metal layer onto the nitride. Dose anyone know that which metal (including seed layer, if needed) can NOT be etched by TMAH (or KOH) solution and BOE solution (buffered oxide etchant, mainly HF)?
   
  I appreciate your help.
   
  Sincerely,
  Zhijian ZHOU
  Hong Kong University of Science and Technology