Study of surface topography in nanometric ductile cutting of silicon wafers

Abstract

Email: xdliu@,SIMTech.a-star.edu.sq p. Subsurface damage in single-crystal silicon induced by ultraprecision grinding was evaluated by means of transmission electron microscopy (TEM) [4, 51. Dislocations appeared in the subsurface zone beneath the amorphous layer and penetrated from 100 nm to 600 nm. However, the AbstractNanometric 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 examined by using an atomic force microscope (AFM). electron microscope (SEM), and their topographies were microcracks appeared Only the layer* The depth Of subsurface damage was p* 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 3dimensional AFM and SEM photographs, in ductile cutting of silicon wafers 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 occurred in the fine grinding process, which would largely reduce the processing time and cost of the heave 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.

A review on ductile mode cutting of brittle materials

“…Surface characteristics produced by DMC of brittle materials were experimentally studied extensively. It was found surface roughness obtained in DMC of silicon was much better than that generated from the grinding [55]. Very smooth surfaces and continuous chips can be achieved in DMC of silicon using an external high hydrostatic pressure of 400 MPa with a diamond tool having an edge radius at nanometer scale [21].…”

“…Typically, the depth of subsurface damage on a silicon wafer induced by an ultra-precision grinding is around 1-3 mm [55]. The average subsurface damage depth imparted by a fine grinding process of silicon wafers is up to 6 mm [56].…”

Study on Removal Mechanism of Fixed-Abrasive Diamond Wire Saw Slicing Monocrystalline Silicon

“…According to the indentation fracture mechanics, the condition of ductile regime cutting is that the cutting depth of grit is less than the critical cut depth d c of monocrystalline silicon. Until now, many studies have been reported on the ductile regime cut of monocrystalline silicon both experimentally and theoretically [4,5]. Brian P. O'Connor performed cutting tests using -45• rake angle diamond tools, results show that the critical chip thickness in monocrystalline silicon for ductile regime removal reaches a maximum of 0.12µm in the [100] direction [4].…”

“…Brian P. O'Connor performed cutting tests using -45• rake angle diamond tools, results show that the critical chip thickness in monocrystalline silicon for ductile regime removal reaches a maximum of 0.12µm in the [100] direction [4]. K.Liu carried out cutting experiments of monocrystalline silicon wafers along (111) direction, SEM observations indicates the max chip thickness of ductile cutting is 0.32µm [5].…”

Experimental Investigation on Brittle-Ductile Transition in Electroplated Diamond Wire Saw Machining Single Crystal Silicon

“…Wafer slicing process is a key technology, the fixed-abrasive diamond wire saw(FADWS) machining technology, with some advantages of low kerf loss and clean working environment for slicing [1][2], is expected to be used for slicing hard-brittle materials such as silicon crystal widely in the future. In the past years, many studies reported that the material removal of single crystal silicon could be in a ductile regime by turning, grinding and lapping [3][4][5], and theoretical study indicated the silicon also could be sawed in a ductile regime possibly [1], but a complete clear understanding about material removal mechanisms in FADWS machining single crystal silicon has not been obtained. And the evidences of change on brittle-ductile transition of material removal are still deficient.…”