[24a-F408-1~8] 9.2 Nanoparticles, Nanowires and Nanosheets

▲ [24a-F408-2] Defect control and enhanced hole gas accumulation of catalyst-free Si/Ge
core-shell heterojunction nanowires for HEMT applications

〇Wipakorn Jevasuwan¹, Yong-Lie Sun¹, Yoshimasa Sugimoto¹, Naoki Fukata¹ (1.NIMS)

Keywords:Silicon, Gemanium, Core-shell nanowires

Nanowires (NWs) are regarded as one of the most promising nanostructures for next-generation high mobility electron transistors (HEMTs), solar cells, and optical sensors due to their outstanding electrical and optical properties. Various types of NWs have been created for potential use in high-performance devices by tailoring their structure and composition, such as axial and radial heterostructures and alloy structures. The p-Si/i-Ge core-shell NWs have been focused on HEMT applications with the design of epitaxial sharp interfaces and type II band alignment. In this study, a top-down method of nanoimprint lithography (NIL) together with Bosch etching was investigated for core-shell NW formations to solve catalyst contamination problems and control the vertical alignment of the NWs. Various techniques of chemical etching and thermal annealing were performed to reduce the diameter of core p-SiNWs with minimization of the NW surface defects. The enhanced hole gas accumulation in i-Ge shell region arrays through the Fano resonance effect was observed. The results indicate great potential for realizing future vertical high-speed transistors using Si/Ge core-shell NWs.