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介观范围。在介观物理和器件应用方面已经有了很大的努力，主要是基于低温下操作的GaAs。为了实现在高温下工作的量子效应器件，我们研究了基于InAs异质结构的介观器件。首先，我们研究了用于器件应用的量子点结构的制造方法。应变后的InAs异质结构继承了不均匀的应变分布，这强烈影响了其能带的不均匀性。自组装的InAs点显示有规则地分布在图案化的GaAs衬底上。其次，我们成功地用InAs点制作了分栅HEMT结构，并观察到该点在高达40K的温度下的单电子充电。我们还成功地制作了铟纳米线，并在80K下观察到了量子化电导。第三，采用铂栅极结构和基于InP的P'栅极结构制备了高性能的InAs沟道场效应管。我们成功地将InAs沟道场效应管结构应用于超导薄弱环节，获得了2meV的IcRn产品。最后，将InAs异质结构应用于共振隧道结构：利用InAs/AlSb RTD测量了弹道电子的能谱，并在77K下观察到多达7个声子副本。具有InAs井和InGaAs预井的RTD的峰值电流几乎增加了一倍。在靠近势垒的阴极GaAs中埋入InAs点的GaAs/AlGaAs RTD由于InAs点的充电而具有记忆效应，并且带电的电子通过共振隧穿被放电。在室温下观察到明显的迟滞现象。

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.