Nanogrinding of SiC wafers with high flatness and low subsurface damage
Nanogrinding of SiC wafers with high flatness and low subsurface damage was proposed and nanogrinding experiments were carried out on an ultra precision grinding machine with fine diamond wheels. Experimental results show that nanogrinding can produce flatness less than 1.0 μm and a surface roughness Ra of 0.42 nm. It is found that nanogrinding is capable of producing much flatter SiC wafers with a lower damage than double side lapping and mechanical polishing in much less time and it can replace double side lapping and mechanical polishing and reduce the removal amount of chemical mechanical polishing.
Remarks:
1) Nanogrinding can produce a flatness less than 1.0 μm and a surface roughness Ra of 0.42 nm for 508 mm SiC wafers.
2) Grinding with #600 diamond wheel is less damaged than double side lapping and grinding with #12000 diamond wheel is less damaged than mechanical polishing.
3) Nanogrinding is capable of producing much flatter SiC wafers with a lower damage than double side lapping and mechanical polishing in much less time.
4) Nanogrinding can replace double side lapping and mechanical polishing and reduce the removal amount for chemical mechanical polishing.
