Investigation on critical crack-free cutting depth for single crystal silicon slicing with fixed abrasive wire saw based on the scratching machining experiments

Abstract

The experimental research of single crystal silicon scratching machining is crucial for micro component machining, precision grinding and fixed abrasive wire saw precision slicing of single crystal silicon. The fixed abrasive wire saw slicing is the main slicing technology of large diameter single crystal silicon slicing process. During the fixed abrasive wire saw slicing process, the brittle material removal mode results in micro crack damage in wafer surface layer, which reduces the strength of sliced silicon wafer, and restricts silicon wafer thinner. The crack-free slicing surface could be obtained while the material is in ductile removal mode. In this study, the scratching machining experiments with the Nano Indenter and Berkovich diamond indenter scratching on single crystal silicon (100) plane along [010] orientation is conducted. The constant normal force 20mN, 100mN, and varied normal force from 0mN to 50mN are applied on the Berkovich indenter. The material removal mode is mainly in ductile regime while 20mN constant normal force, and the material removal mode is mainly in brittle regime and cleavage fracture emerge while 100mN constant normal force. The tangential friction force of scratching machining process changes from smooth to fluctuate when the varied normal force from 0mN to 50mN, and material removal mode from ductile regime to brittle regime. The critical normal force of ductile transition to brittle is 26mN. However, the scratching machining experimental results near the ductile regime removal mode show that the scratch exists obvious elastic recovery. The elastic recovery of scratch affects the material removal amount and machining accuracy. Based on the scratching machining experimental results, the critical crack-free cutting depth per abrasive for single crystal silicon slicing with fixed abrasive wire saw is analyzed. The results in this paper are useful for the single crystal silicon micro component machining and slicing process parameters selection of fixed abrasive wire saw.