Hi all,


   I would like to ask whether there is anyone who has experience on etchant Pt

and Ti layer.  By the way, thank you first.

   I have a Pt layer on top of a Ti layer. The Ti layer is used for promote
ahersion between Pt and Si substate. Therefore, it is not too thick. And at the

beginning, I use lift-off to pattern them together. But as my device size goes
small (~5um), I can't use lift-off and all the patterns are peel off.
Therefore, I would try HCL+HNO3 to etch Pt at around 50 degree C. And after I
etched Pt, I can't identify whether the rest layer is Ti or just the surface of

Si substrate. Therefore, I would like to ask whether Pt etchant I use can etch
Ti also? And can you suggest me on how to pattern my Pt/Ti layer if you have
certain experience? Also, I use AZ4215 as the mask. But when I use the Pt
etchant to etch Pt, the surface of AZ5214 is extremely rough. What do I do?


Thank you
Hoyin