Hi Nels, > Here is one that I used for crystalline germanium: > R. Leancu, N. Moldovan, L. Csepregi, and W. Lang, "Anisotropic etching of > germanium," Sensors and Actuators A, vols. 46-47, pp. 35-37, 1995. can you give me more informations? Which type of wafer have you used ? (100) like in the article you suggested me ? Which mask have you used ? A Cr mask like suggested in this article or another type of mask? Which etchant? It seams article suggest ellison or kern solutions. Do you know etch rate of those solutions? They are not reported in the article :OO Do you have any informations about isotropic etching of germanium ? In particular, reading the article you suggested, it seams that Billing and Holmes solutions are isotropic etchants, is this correct ? > I am pretty sure that these same authors also published another paper on > the topic in another journal but I cannot find it at this time. I've found this Synchrotron-radiation-induced wet etching of germanium, Applied Physics Letters -- August 26, 2002 -- Volume 81, Issue 9, pp. 1741-1743 Bulk micromachining of Ge for IR gratings W Lang et al 1996 J. Micromech. Microeng. 6 46-48 Does someone have informations also about isotropic etching of germanium ? Thanks Andrea