Formation of Ge Quantum Dot and Shell for Si on Insulator Applications

• Main Authors: Zi-Hao Wu, 吳梓豪
• Other Authors: Pei-Wen Li
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/08688797233761845118

碩士 === 國立中央大學 === 電機工程學系 === 102 === This thesis continuously studied the formation of Ge QDs using thermal oxidation of poly-SiGe pillar/Si3N4/Si heterostructure in our lab, and further discussed the dependence of morphology and internal defects of Ge QD between oxidation and annealing conditions. Meanwhile, the author used this process on poly-SiGe pillar/ Si3N4/Si on insulator substrate in order to realize Ge/SiO2/Si on insulator heterostructure advantaging in the gate engineering of Ge MOSFET and phototransistor. This thesis used transmission electron microscopy (TEM), energy dispersive X-ray (EDX) mapping and Raman analysis to investigate the evolution of morphology, crystallinity, lattice orientation, defects, Ge concentration and stress of Ge QD and shell under different thermal budget by modifying oxidation and annealing conditions. The author found that Ge QD catalytically enhances the local oxidation of underlying Si3N4 and Si. The released Si atoms diffuse into Ge QD and make the migration of Ge QD in Si3N4 and Si. In addition, the quantity of Si inward Ge QD obviously changes the morphology of Ge QD. This thesis investigated the relationship between Ge QD/shell using selective oxidation and thermal budget. The demonstrated SiGe shell with uniform thickness, subject to compressive stress and stable (111) lattice orientation not only can be used in self-aligned Ge QD but also have good SiO2 quality between Ge QD and shell. Therefore, this heterostructure can be used as the application of gate stack and the channel of Ge MOSFET and phototransistor.