Dear Jeong,

You can use wet chemical etching to remove ZnO for example from metal substrate. As an example you may use H2O2 to selectively etch ZnO.

Please for further information look at the link: Article Well-controlled wet etching of ZnO films using hydrogen pero...

For other selective etching solution you can search the web.

Best wishes

As Abdelhalim notes, you can use various chemicals which will dissolve/react with the metal oxide but not with the metal electrodes. In past work on ZnO, my group used HCl to remove ZnO from Si substrates. This may be suitable for some metal electrodes, such as Au, but not for others which will react with HCl.

Thanks a lot, Abdelhalim Zekry , Keith Fraser and Thomas Breuer.

There are answer that i wanted.