Structural Insight on Strain and Ge Content within SiGe Nanosheet Created by Proximal Ge Nanospheres

• Main Authors: Chen, Chia-Tsong, 陳家驄
• Other Authors: Li, Pei-Wen
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/52bkwf

碩士 === 國立交通大學 === 電子研究所 === 107 === In this thesis, fabrication and characterization of silicon-germanium (SiGe) nanosheet as well as the associated nanosheet channel devices are investigated. By tuning the duration of thermal oxidation, we have demonstrated the precise controllability of penetration of Ge nanospheres (NPs) into Si substrate through single-step thermal oxidation of SiGe nano-pillar. In order to effectively realize Si1-xGex nanosheet, the lithographical patterning and etching profile of nanostructure are to be optimally designed. As the results, Si1-xGex nanosheet exhibits excellent crystallinity were observed via both the clear lattice fringes in high-resolution transmission electron microscopy (TEM) and the sharp diffraction spot in nanobeam electron diffraction (NBD) patterns. In addition, the maximum Ge composition and lattice constant in Si1-xGex nanosheet have a monotonically increasing dependence on the depth of penetration of the intact Ge NPs into Si substrate. Structural properties of Si1-xGex nanosheet under the condition of both lateral shift and exploded Ge NPs are also discussed. 　　All the experimental results provide a novel nanosheet device structure that is discussed in fabrication process with minor test modules. We can expect that nanosheet structure devices will demonstrate very low interface trap density of SiO2 interlayer between Ge NPs and Si1-xGex nanosheet as well as excellent current characteristic that can provide an excellent reference for future integrated circuit development.