I'm having problem on etching a normal borosilicate glass with HF(conc. 4:1 not buffered). The etching process comes irregular and strip off the resist after 25mins I run the process. Is there anyone that have a better idea on how to etch it? Someone suggest to etch the glass using FIB or Ion beam etching technique. Is there anyone that have experience on that. Any help would be appreciated. Thanks Adriele