Investigation of Crystallographic Aspects of Subsurface Damage Induced by Grinding Using Micro-Raman Tomographic Imaging

Abstract The objective of this study is to propose and develop an evaluation method on the process damages of sapphire wafers, regarding crystallographic aspects of the damages by use of tomographic imaging techniques with laser Raman microscopy (called as micro Raman tomographic imaging: mRTI). In this paper, tomographic images with the peak width and the shift of the peak position were observed with mRTI, on c-plane cut sapphire wafers along a-plane, with micro fractures induced by brittle-mode grinding. Fractures along m-plane from the surface to 2–7 microns-depth, and fractures along r-plane from the bottom end of the m-plane fracture to 14 microns-depth, subsequently induced elastic strain field around the fractures, could be visualized without destructions of the wafers.