A Nanomechanical Analysis of Deformation Characteristics of 6H-SiC Using an Indenter and Abrasives in Different Fixed Methods

Abstract

The super-precise theory for machining single crystal SiC substrates with abrasives needs to be improved for its chemical stability, extremely hard and brittle. A Berkovich indenter was used to carry out a systematic static stiffness indentation experiments on single crystal 6H-SiC substrates, and then these substrates were machined by utilizing fixed, free, and semi-fixed abrasives, and the nanomechanical characteristics and material removal mechanisms using abrasives in different fixed methods were analyzed theoretically. The results indicated that the hardness of C faces and Si faces of single crystal 6H-SiC under 500 mN load were 38.596 Gpa and 36.246 Gpa respectively, and their elastic moduli were 563.019 Gpa and 524.839 Gpa, respectively. Moreover, the theoretical critical loads for the plastic transition and brittle fracture of C face of single crystal 6H-SiC were 1.941 mN and 366.8 mN, while those of Si face were 1.77 mN and 488.67 mN, respectively. The 6H-SiC materials were removed by pure brittle rolling under three-body friction with free abrasives, and the process parameters determined the material removal modes of 6H-SiC substrates by grinding with fixed abrasives, nevertheless, the materials were removed under full elastic-plastic deformation in cluster magnetorheological finishing with semi-fixed abrasives.

Recent Advances in Chemical Mechanical Polishing Technologies of Silicon Carbide

“…6 For application, the roughness (Ra) of the substrate is usually required to be below 0.3 nm. 7 The surface flattening technology of silicon carbide materials must be continuously improved to meet the needs of industry development. Typical wafer processing processes include ingot processing, slicing, edging, laser marking, rough grinding, fine grinding, CMP, post-CMP cleaning, inspection, packaging, and other process steps.…”

A Numerical Analysis of Ductile Deformation during Nanocutting of Silicon Carbide via Molecular Dynamics Simulation

“…For example, by experimental methods, Ding et al [ 8 ] conducted both ultrasonic-assisted and conventional grinding experiments on the monocrystalline SiC; they discovered that the grinding force, surface roughness, and profile wave height were effectively reduced by the ultrasonic-assisted grinding. Pan et al [ 9 ] performed systematic static stiffness indentation experiments on 6H-SiC ceramics, and machined the workpieces by utilizing fixed, free, and semi-fixed abrasives. Finally, they theoretically analyzed the nanomechanical properties and material removal mechanisms of SiC ceramics.…”

Mechanical Load-Induced Atomic-Scale Deformation Evolution and Mechanism of SiC Polytypes Using Molecular Dynamics Simulation

“…Goel et al [ 9 ] studied the nanomechanical response of 4H-SiC through a quasi-static nanoindentation test, and the critical shear stress of elastic–plastic transition is about 21 GPa. Pan et al [ 10 ] compared the critical load of elastic–plastic transition between C-face and Si-face in 6H-SiC. The results showed that the elastic–plastic transformation threshold of the Si-face was lower.…”