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，开发了一个程序，通过使用能量势垒的逐步近似计算电子的隧穿概率来模拟电流-电压特性，并且模拟了双势垒结构在温度下，特别是在室温下的电流-电压特性。用内光电发射法测量了金属氧化物半导体（MOS）二极管的硅-二氧化硅界面的能垒高度，并首次测定了外延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，已经开发了形成具有高电绝缘性能和可靠性的氧化二氧化硅薄膜的热氧化技术，并且由于通过具有氧化二氧化硅薄膜的MOS二极管的漏电流可以通过在晶片加热过程中精确控制氧化物生长来减小，因此隧道电流的可控性已经增强。使用模拟程序制作的MOS二极管的电流-电压特性的分析表明，在半导体区，由于薄膜薄，用于电子隧穿的二氧化硅薄膜的能垒高度降低。发展了一种将一片覆有SiO_2薄膜的硅片与另一片硅片键合的技术，制备了垂直结构的硅/二氧化硅双势垒，并制备了具有SiO_2薄膜埋氧层的绝缘体上硅衬底。

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.