The discussion revolves around the use of metal masks for BOE (Buffered Oxide Etch) or HF (Hydrofluoric Acid) etching processes. Participants explore the effectiveness of different metals in preventing issues associated with photoresist peeling during etching.
Participants express differing opinions on the best metal to use for masks, and there is no consensus on the effectiveness of photoresist versus metal masks. The discussion remains unresolved regarding the optimal material choice.
There are limitations regarding the assumptions about the etching processes and the specific conditions under which different metals may perform better or worse. The discussion does not clarify the dependence on specific etching parameters or the context of use for each metal.
what about using photoresist?Yinxiao Li said:I am thinking about using a metal mask for BOE or HF etching because I realize that for normal photoresist, it will gradually peel off and affect my results. I don't know which metal is the best--so far, I see people use Cr/Au, Al, and Ni. Anybody knows which metal will give the best result?
Thanks. I am still looking for the best mask that prevents this underetching...leright said:I think the reason it peels is because of underetching (the HF etches underneath the resist as well, since it is an isotropic etchant). See this document for tips.
http://www.microchemicals.com/technical_information/hf_etching.pdf