a Strasbaugh model 7AF wafer backgrinder using a diamond cup coarse and ﬁne wheels. The used ﬁne grinding wheels were no. 2000 mesh ca. diamond size 3–6 m or ﬁner resin bonded diamond wheels. The grinding process was not optimized for cavity wafers, but a process that yielded a smooth surface and a thin subsurface damage layer was applied.