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

Area of Science:

• Materials Science
• Nanotechnology
• Computational Physics

Background:

• Silicon carbide (SiC) is vital for high-performance power electronics due to its superior electrical properties.
• Cost-effective fabrication of SiC wafers necessitates understanding material deformation and removal mechanisms.

Purpose of the Study:

• Investigate the origins of differing elastic-plastic deformation characteristics among SiC polytypes (3C-SiC, 4H-SiC, 6H-SiC).
• Analyze deformation mechanisms during nanoindentation using molecular dynamics simulations.

Main Methods:

• Employed molecular dynamics (MD) simulations to model nanoindentation on SiC polytypes.
• Analyzed atomic structures, pair correlation functions, and dislocation distributions post-simulation.

Main Results:

• Elastic-plastic deformation in SiC polytypes is primarily driven by amorphous phase transformation and dislocation behaviors.
• Most amorphous atoms recovered upon unloading.
• 3C-SiC exhibits mainly perfect dislocations, while 4H-SiC and 6H-SiC show fewer perfect dislocations and the formation of stacking faults.

Conclusions:

• The study elucidates the distinct deformation mechanisms of SiC polytypes at the atomic level.
• Findings provide insights into optimizing SiC wafer machining for advanced electronics.