Quantum Interference Devices Controlled by Metals Buried in Semiconductors

埋藏金属控制电子波双棱镜的分析日本和瑞典合作提出的电子波双棱镜进行了分析。特别地，我们从理论上考察了电子源相干性对干涉图样对比的影响，揭示了要实现双棱镜干涉，需要一个发射横向能量扩散为亚meV的电子束的高相干源。为了实现这种高相干电子束，提出了一种相干发射极，其中量子阱的谐振能级与源的费米能级之间的能量差由一个后门精确控制，并从理论上证明了其工作原理。周期为几十nm的周期细周期电极对双棱镜中电子波现象的观察表明，在测量小干涉电流时，电极间的隔离是非常重要的，通过异质结导带不连续和干刻蚀可以达到隔离要求。我们提出了一种新的晶体管，通过采用双势垒谐振隧道结构和金属线的组合来产生热电子并穿过未掺杂的半导体区域，我们试图用我们提出的晶体管来演示双棱镜运行所需的吸引电位的形成。在对谐振隧道结构晶体生长和半导体中埋金属进行了基础研究之后，我们利用OMVPE材料制作了在GaAs中再生长埋钨的装置。通过对实测数据的分析，首次证实了埋藏金属妻子周围有吸引电位的形成。此外，为了减少发射极漏电流，我们在InP半绝缘衬底上制作了晶体管，并采用独立线连接。从测量的I-V特性来看，通过检查负差分电阻处的峰值电流值，表明埋地金属线栅极能够产生吸引电位，并且减少了泄漏电流。因此，我们已经能够展示我们的设备的潜力。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