A STUDY ON SOI QUANTUM DEVICES WITH VARIABLE FUNCTION BY RESONANT/NON-RESONANT CONTROL IN VERTICAL RESONANT TUNNELING STRUCTURES

为了设计硅/二氧化硅双势垒结构，利用能量势垒的逐次阶跃近似，通过计算电子的隧穿概率来模拟电流-电压特性，并对双势垒结构在温度下，特别是室温下的电流-电压特性进行了模拟。用内部光电发射法测量了金属氧化物半导体（MOS）二极管硅-二氧化硅界面的能垒高度，并首次测定了超薄二氧化硅薄膜的能垒高度。为了实现具有硅/二氧化硅双势垒结构的量子器件，提出了一种形成具有高绝缘性能和可靠性的超薄二氧化硅薄膜的热氧化技术，通过精确控制晶圆加热过程中氧化物的生长，可以降低超薄二氧化硅薄膜上MOS二极管的漏电流，从而提高了隧道电流的可控性。利用模拟程序对MOS二极管的电流电压特性进行了分析，结果表明，在超薄状态下，薄膜越薄，用于电子隧穿的二氧化硅薄膜的能垒高度就越低。本文提出了一种将覆盖超薄二氧化硅薄膜的硅片与另一片硅片粘接的技术，以制备硅/二氧化硅双垒的垂直结构，并制备了覆盖超薄二氧化硅薄膜氧化物的绝缘体上硅衬底。

A program simulating current-voltage characteristics through tunneling probability calculation of electrons using successive step approximation of energy barriers has been developed so as to design silicon/silicon dioxide double barriers structures, and current-voltage characteristics of double barriers structures at temperatures, and particularly at room temperature, have been simulated. Energy barrier heights at the silicon-silicon dioxide interface of metal-oxide-semiconductor (MOS) diodes fabricated have been measured by internal photoemission, and energy barrier heights of ultrathin silicon dioxide films have been determined for the first time. An thermal oxidation technology forming ultrathin silicon dioxide films with high electrical insulating performance and reliability has been developed in order to realize quantum devices with silicon/silicon dioxide double barriers structures, and the controllability of tunneling current has been enhanced because leak current through MOS diodes with an ultrathin silicon dioxide film can be decreased by the precise control of oxide growth during wafer heating-up processes. The analysis of current-voltage characteristics of MOS diodes fabricated using the simulation program has suggested that the energy barrier height of a silicon dioxide film for the tunneling of electrons is lowered as the film is thin in the ultrathin regime. A technology bonding one wafer covered with an ultrathin silicon dioxide film to another wafer has been developed to fabricate the vertical structure of silicon/silicon dioxide double barriers, and silicon-on-insulator substrates with the buried oxide of an ultrathin silicon dioxide film have been prepared.