Compressive elastic behavior of single-crystalline 4H-silicon carbide(SiC) nanopillars  

作　　者：FAN SuFeng LI XiaoCui FAN Rong LU Yang 

机构地区：[1]Department of Mechanical Engineering,City University of Hong Kong,Hong Kong 999077,China [2]Department of Materials Science and Engineering,City University of Hong Kong,Hong Kong 999077,China [3]Nanomanufacturing Laboratory(NML),Center for Advanced Structural Materials(CASM),City University of Hong Kong Shenzhen Research Institute,Shenzhen 518057,China

出　　处：《Science China(Technological Sciences)》2021年第1期37-43,共7页中国科学（技术科学英文版）

基　　金：supported by Hong Kong Research Grant Council (RGC)(Grant No. U11207416);City University of Hong Kong (Grant No.7005234);National Natural Science Foundation of China under the Excellent Young Scientists Fund (Grant No. 11922215)。

摘　　要：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.

关 键 词：silicon carbide elastic deformation compressive behavior in situ SEM/TEM elastic strain engineering 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TN304.24[电子电信—物理电子学]