Mesoscopic Devices Using InAs Heterostructures and Their Applications

随着微电子技术的出现，器件的尺寸及其物理现象已经达到了介观的程度。在介观物理和器件应用方面，人们已经做出了很大的努力，主要是基于在低温下工作的GaAs。我们研究了基于InAs异质结构的介观器件，以实现在更高温度下工作的量子效应器件。首先，我们研究了量子点结构的制造方法，以达到器件应用的目的。应变InAs异质结构具有不均匀的应变分布，这对能带的不均匀性有很大的影响。自组装的InAs点被证明是有规律地分布在图案化的GaAs衬底上。第二，我们成功地制备了InAs点分裂栅HEMT结构，并在40 K下观察到了点的单电子充电;第三，我们成功地制备了InAs量子线，并在80 K下观察到了量子化电导。采用铂栅结构和InP基P'栅结构制备了高性能InAs沟道FET，并成功地将InAs沟道FET结构应用于超导领域最后，将InAs异质结应用于共振隧穿结构：用InAs/AlSb RTD测量了弹道电子的能谱，在77 K下观察到了7个声子副本。在GaAs/AlGaAs RTD中，InAs点埋在阴极GaAs中，靠近势垒，由于InAs点的充电，显示出记忆效应，带电电子通过共振隧穿放电。在室温下观察到明显的滞后。

With the advent of microelectronics, the device size and its physical phenomena have reached to the mesoscopic region. There have been strong effort on mesoscopic physics and device applications mostly based on GaAs operated at cryogenic temperatures. We have investigated mesoscopic devices based on InAs heterostructures in order to realize quantum effect devices operated at higher temperatures. First of all, we have investigated fabrication method of quantunm dot structures for the purpose of device applications. Strained InAs heterostructure was shown to inherit inhomogeneous strain distribution which strongly affects its energyband inhomogeniety. Self-assembled InAs dots were shown to distribute regularly on patterned GaAs substrates. Secondly, we have succeeded in fabricating split-gate HEMT structure with InAs dots and observed single electron charging of the dot at up to 40K.We have also succeeded in fabricating InAs wuantum wires and observed quantized conductance at 80K.Thirdly, high performance InAs channel FETs have been fabricated by Platinum gate structure and P' gate structure based on InP.We have successfully applied InAs channel FET structure to superconducting weak links and obtaind IcRn product of 2meV.Finally, InAs heterostructures were also applied to resonat tunneling structures : energy spectra of ballistic electrons were measued by using InAs/AlSb RTD and up to seven phonon replicas were observed at 77K.RTD with InAs well and InGaAs pre-well has been shown to have almost doubled peak current. GaAs/AlGaAs RTD with InAs dots buried in cathode GaAs adjacent to the barrier has been shown to have memory effect due to the charging of InAs dots and charged electrons were shown to be dischraged by resonant tunneling. The clear hysteresis were observed at room temperature.