Quantum Interference Devices Controlled by Metals Buried in Semiconductors

掩埋金属控制的电子波双棱镜分析日本和瑞典合作提出的电子波双棱镜的分析。特别从理论上考察了电子源的相干性对干涉图样对比度的影响，发现要实现双棱镜的干涉，需要一个横向能散为亚MeV的高相干源。为了实现这样的高相干电子束，提出了一种利用背栅精确控制量子阱的谐振能级与源的费米能级之间的能量差的相干发射器，并从理论上证明了它的工作原理。对形成周期为几十nm的周期细电极的隔离技术的改进。用周期为几十nm的周期细电极观察双棱镜中的电子波现象表明，隔离…在小干扰电流的测量中，电极间n的增加是非常重要的，并且通过异质结的导带不连续和干法刻蚀实现了所需的隔离。我们提出了一种新型的晶体管，它通过采用双势垒共振隧穿结构和金属线相结合来产生热电子并通过未掺杂的半导体区，从而实现了双棱镜的工作所需的吸引势的形成。在对共振隧穿结构的晶体生长和在半导体中埋入金属进行了基础性研究后，我们用OMVPE再生长的方法制作了在GaAs中埋入钨的器件。通过对测量数据的分析，首次证明了埋入地下的金属妻子周围形成了吸引势。此外，为了减小发射栅漏电流，我们在InP半绝缘衬底上制作了晶体管，并用自支撑导线布线。从测量的I-V特性可以看出，埋入金属线栅能够产生吸引电位，通过检测负差阻处的峰值电流，可以降低漏电流。因此，我们已经能够展示我们设备的潜力。较少

Analysis of Electron Wave Biprism Controlled by Buried MetalAnalysis of electron wave biprism proposed by a collaboration between Japan and Sweden has been proceeded. Especially, we have theoretically examined influences of coherence of electron source on contrast of interference pattern and it has been revealed that a highly coherent source emitting electron beam with a transverse energy spread of sub meV has been required to realize interference by the biprism. To realize such highly coherent electron beam, a coherent emitter, where a energy difference between a resonant level of a quantum well and a Fermi level of a source has been precisely controlled by a back gate, has been proposed and theoretically proved its operation principle.Improvement of Isolation Technique on Formation of Periodic Fine Electrodes with Period of a Few Tens nmFor observations of electron wave phenomenon in the biprism by periodic fine electrodes with period of a few tens nm, it has been shown that isolatio … More n between electrode has been very important on small interference current measurement, and the required isolation has been achieved by conduction band discontinuity of heterojunction and dry etching.Demonstration of Attractive Potential Formation by Buried Metal Hot Electron Transistor with Metal Wire GateWe have proposed a novel transistor where hot electrons are generated and travel through undoped semiconductor region by adopting a combination of double-barrier resonant-tunneling structure and metal wire, and we has attempted to demonstrate attractive potential formation required in operation of the biprism by our proposed transistor. After fundamental studies of crystal growth for resonant-tunneling structure and burying metal in semiconductors, we have fabricated the device by re-growth to bury Tungsten in GaAs using OMVPE. By analysis of measured data, for the first time, a formation of attractive potential around the buried metal wife has been demonstrated. Furthermore, to reduce emitter-gate leakage current, we have fabricated transistors on InP semi-insulating substrate and wired by free-standing wire. From measured I-V characteristics, it has been shown that buried metal wire gate has enabled to produce attractive potential and leakage current has been reduced by examining value of peak current at negative differential resistance. Therefore,we have been able to show the potential of our device. Less