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Study on Nanofabrication and One-Dimensional Quantum Effects

纳米加工与一维量子效应研究

基本信息

批准号：
61420019
负责人：
GAMO Kenji
金额：
$ 24.58万
依托单位：
Osaka University,
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1988
项目状态：
已结题

项目摘要

The present project is to establish the basis of nanofabrication technology and to investigate mesoscopic effects and their control by external fields in nanostructures, which are important for future quantum devices. The results are summarized as follows.1) It was demonstrated that SiO_2 and Si_3N_4 are effectively patterned by ion beam assisted etching with high etching rate, more than 100 times faster than the physi-cal sputter etching. Reduction of process induced damage in GaAs was also demonstrated by using low energy focused ion beams. These results are important for maskless etching or deposition using focused ion beams.2) We, first, observed universal conductance fluctuations in GaAs which comes from interference of electron waves in mesoscopic structures. In addition, we also found nonlocality and asymmetry of magnetoresistance. This was realized by using nanofabrication technology which we have established.3) We, first, observed a clear Aharanov-Bohm effect in GaAs/GaAlAs heterostructure submicron ring devices. This indicates the possibility of controlling the inter-ference effects by an external fields, which is important for device applications.4) We observed various ballistic transport effects in GaAs/GaAlAs heterostructure quantum wires. We, first, demonstrated that a large negative resistance appears at bents or interconnects of current path becouse electrans travel straightforward in ballistic region.5) We observed one dimensional quantum size effect in narrow GaAs/GaAlAs wires.

本项目旨在建立纳米纤维技术的基础，并研究纳米结构中的介观效应及其由外场控制，这对未来的量子器件很重要。结果表明：（1）离子束辅助刻蚀可以有效地刻蚀SiO_2和Si_3N_4，刻蚀速度快，比物理溅射刻蚀快100倍以上。减少过程中引起的损伤GaAs也表明，通过使用低能量聚焦离子束。这些结果对于无掩模刻蚀或聚焦离子束沉积具有重要意义。2）首先，我们观察到了GaAs中普遍存在的电导波动，它来自于电子波在介观结构中的干涉。此外，我们还发现了磁电阻的非局域性和非对称性。3）首先，我们在GaAs/GaAlAs异质结亚微米环形器件中观察到了明显的Aharanov-Bohm效应。这表明了用外场控制干涉效应的可能性，这对器件的应用具有重要意义。4）我们在GaAs/GaAlAs异质结构量子线中观察到了各种弹道输运效应。我们首先证明了由于电子在弹道区直接传播，在电流路径的弯曲处或互连处会出现大的负电阻。5）我们观察到GaAs/GaAlAs窄线的一维量子尺寸效应。