Compressive elastic behavior of single-crystalline 4H-silicon carbide (SiC) nanopillars
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https://doi.org/10.1007/s11431-020-1678-6
•Article•
Compressive elastic behavior of single-crystalline 4H-silicon carbide (SiC) nanopillars 1
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FAN SuFeng , LI XiaoCui , FAN Rong & LU Yang 1
Department of Mechanical Engineering, City University of Hong Kong, Hong Kong 999077, China; Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong 999077, China; Nanomanufacturing Laboratory (NML), Center for Advanced Structural Materials (CASM), City University of Hong Kong Shenzhen 2
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Research Institute, Shenzhen 518057, China Received April 10, 2020; accepted June 12, 2020; published online August 24, 2020
As a wide-bandgap semiconductor, 4H-SiC is an ideal material for high-power and high-frequency devices, and plays an increasingly important role in developing our country’s future electric vehicles and 5G techniques. Practical applications of SiCbased devices largely depend on their mechanical performance and reliability at the micro- and nanoscales. In this paper, singlecrystal [0001]-oriented 4H-SiC nanopillars with the diameter ranging from ~200 to 700 nm were microfabricated and then characterized by in situ nanomechanical testing under SEM/TEM at room temperature. Loading-unloading compression tests were performed, and large, fully reversible elastic strain up to ~6.2% was found in nanosized pillars. Brittle fracture still occurred when the max strain reached ~7%, with corresponding compressive strength above 30 GPa, while in situ TEM observation showed few dislocations activated during compression along the [0001] direction. Besides robust microelectromechanical system (MEMS), flexible device and nanocomposite applications, the obtained large elasticity in [0001]-oriented 4H-SiC nanopillars can offer a fertile opportunity to modulate their electron mobility and bandgap structure by nanomechanical straining, the so called “elastic strain engineering”, for novel electronic and optoelectronic applications. silicon carbide, elastic deformation, compressive behavior, in situ SEM/TEM, elastic strain engineering Citation:
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Fan S F, Li X C, Fan R, et al. Compressive elastic behavior of single-crystalline 4H-silicon carbide (SiC) nanopillars. Sci China Tech Sci, 2020, 63, https://doi.org/10.1007/s11431-020-1678-6
Introduction
Silicon carbide is widely used in different fields because of its excellent properties [1]. The high strength and hardness, high thermal shock and corrosion resistance make SiC perform excellent in extreme temperature environments. Therefore, it has broad applications in grinding materials, cutting blade, and the brake system. In addition to mechanical properties, because of the high radiation resistance, SiC becomes an ideal candidate for nuclear applications, especially in fusion reactors [2,3]. Moreover, as a representative *Corresponding author (email: [email protected])
third-generation semiconductor material, SiC can be used as high-power, high-frequency electronic devices in harsh environment by taking advantage of its wide bandgap and
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