Study of surface topography in nanometric ductile cutting of silicon wafers

Abstract

Nanometric ductile cutting experiments of silicon wafers have been carried out using an ultraprecision lathe with a single crystal diamond tool in this study. The machined silicon wafer surfaces were examined by using a scanning electron microscope (SEM), and their topographies were examined by using an atomic force microscope (AFM). SEM and AFM observations of the machined silicon wafer surfaces indicated that ductile mode cutting of silicon wafers could be achieved in a certain cutting condition and tool geometry. The wafer surfaces achieved in ductile mode cutting were much smoother than that achieved in brittle mode cutting. Viewing from the 3-dimensional AFM and SEM photographs, in ductile cutting of silicon wafer feed marks were clearly displayed on the machined wafer surfaces. Cross-sectional observations using a SEM showed that in ductile cutting of silicon wafers the subsurface damage was largely reduced compared to that occurring in the fine grinding process, which would largely reduce the processing time and cost of the heavy chemical-mechanical polishing process. Using the ductile cutting process to replace the fine grinding process in the current wafer fabrication will greatly increase the product quality and production rate, as well as largely reduce the production cost.