HIGH-RESOLUTION STUDIES OF CRYSTALLINE DAMAGE-INDUCED BY LAPPING AND SINGLE-POINT DIAMOND MACHINING OF SI(100)

Si(100) wafers were prepared by both diamond turning and standard lapp ing and polishing techniques. For single-point diamond machining, char acterization of subsurface damage resulting from ductile-regime machin ing identified a plastic-yield zone consisting of slip planes and disl ocation networks extending 1 to 3 mu m deep despite surface root-mean- square roughness values as low as 5 nm. For conventional lapping and p olishing using alumina grit, a transition from brittle to ductile yiel d was observed for grit sizes less than 300 nm. Subsurface damage dept h correlated to surface roughness in a more straightforward manner tha n for the diamond point machining. Completely damage-free material rem oval was obtained only when a chemical component to the polishing was present.