A state-of-the-art review of ductile cutting of silicon wafers for semiconductor and microelectronics industries

Abstract

Silicon is a typical functional material for semiconductor and optical industry. Many hi-tech products like lenses in thermal imaging, solar cells, and some key products of semiconductor industry are made of single crystal silicon. Silicon wafers are used as substrate to build vast majority of semiconductor and microelectronic devices. To meet high surge in demand for microelectronics based products in recent years, the development of rapid and cost efficient processes is inevitable to produce silicon wafers with high-quality surface finish. The current industry uses a sequence of processes such as slicing, edge grinding, finishing, lapping, polishing, back thinning, and dicing. Most of these processes use grinding grains or abrasives for material removal. The mechanism of material removal in these processes is fracture based which imparts subsurface damage when abrasive particles penetrate into the substrate surface. Most of these traditional processes are extremely slow and inefficient for machining wafers in bulk quantity. Moreover, the depth of subsurface damage caused by these processes can be up to few microns and it is too costly and time consuming to remove this damage by heavy chemical–mechanical polishing process. Therefore, semiconductor industry requires some alternative process that is rapid and cost effective for machining silicon wafers. Ductile cutting of silicon wafer has the potential to replace the tradition wafer machining processes efficiently. If implemented effectively in industry, ductile cutting of silicon wafers should reduce the time and cost of wafer machining and consequently improve the productivity of the process. This paper reviews and discusses machining characteristics associated with ductile cutting of silicon wafers. The limitations of traditional wafer fabrication, the driving factors for switching to ductile cutting technology, basic mechanism of ductile cutting, cutting mechanics, cutting forces, surface topography, thermal aspects, and important factors affecting these machining characteristics have been discussed to give a systematic insight into the technology.