Hello everyone, I'm a graduate student. Now I'm doing GaN etch with Cl2/BCl3 gas (ICP-RIE) with GXR601
When the etch depth is under 100nm, the surface (PR X) is clean but up to 200~300nm the surface become very rough and some mark on it. I want to know reason of this... I do soft bake 90C 1min, PEB 110C 1min, Hard Bake 110C 1min 30sec.
Thank you for answer.