Electrical transport in Si-based nano-structures

• Main Authors: Kun-Yuan Wu, 吳昆源
• Other Authors: Hung-Hsiang Cheng
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/28370903036670632324

博士 === 國立臺灣大學 === 電子工程學研究所 === 101 === Nanoscience has attracted great attention from both academia and industry. Consequently, research on “nanoscience” has advanced rapidly. In the move toward “nano-scale semiconductor”, the physical dimensions of the structures under investigation have moved from 3D bulk material, to 2D films (heterostructure), then 1D quantum wire, and 0D quantum dot. The reduction in the physical dimensions of the structure gives rise to different energy profile that modifies the performances of the devices. This thesis investigate the electrical transport of three types of Si-based nanostructures: (a) n-type resonant tunneling diodes (RTD) with double barrier heterostructure, (b) p-i-p structure with delta-doped at the i-layer, and (c) silicon on insulator field-effect transistor (ETSOI-FET). Different theoretical models are employed to analyze the electrical characteristics depending on the structure of the devices, including conventional quantum transport, multi-channel transfer-matrix. On the RTD, analysis is performed on structure deposited on fully and partially relaxed buffer layer. We show that room temperature peak to valley ratio can be achieved by using partially relaxed SiGe buffer layers. For the p-i-p structure with boron delta-doped in the i-layer, we report both experimental measurement and theoretical analysis of the electrical tunneling. The characteristic of bistability is found. From the analysis, it shows that the charge accumulation at the delta-doped in the i-layer dominated the observation. We have also proposed a theoretical analysis on the transmission coefficients and the transport currents in the ETSOI-FET under the distorted fields formed by gate bias and drain bias which makes ballistic transport non-ballistic.