Study of Ultra-Thin-Film/Ultra-Fine-Structure Devices

采用原子层层金属有机化学气相沉积方法成功地制备了氧化物超导体YBaCuO超薄膜。根据计算机程序顺序地提供了倍二酮复合体的前体。由于促进了物种在生长表面的迁移，得到了非常光滑的表面，其梯形长度分别为：SrTiO_3衬底330 nm，NdGaO_3衬底660 nm。用350keV电子束辐照YBaCuO薄膜，获得了高超导临界电流。临界电流的磁场分布表明，得到了非常均匀的结。400K下的退火改善了结的退化问题。采用原子层外延技术，以氢原子为还原剂，制备了硅、锗超薄膜。一种用…实现的新方法更多的是将高压的硅源气体限制在反应室中。建立了每周期一个单分子层的ALE条件。还研究了硅氧化物和氮化物的原子层沉积。提出了用于硅量子线器件的沟槽-氧化物-金属-氧化物-半导体结构。利用超级计算机模拟了沟槽MOS结构对电子的限制。采用电子束光刻和电子回旋共振反应离子刻蚀方法制作了样品器件。在超低温下测量的电容-电压特性中得到了量子效应的信号。在硅烷和氢气组成的等离子体池中制备了直径小于10 nm的纳米硅。通过分离成核和晶体生长的思想，得到了单分散的颗粒。用原子力显微镜和电子显微镜对纳米硅的结构进行了表征。在室温下观察到可见的光致发光。在室温下观察到了纳米硅的电流-电压特性中的库仑阶梯现象，即单电子隧穿效应。对降解机理、超大规模积分和神经网络的应用进行了讨论。较少

Ultrathin films of oxide superconductors YBaCuO have been prepared successfully by atomic layr-by-layr metalorganic chemical vapor deposition. Precursors of betadiketonate complex have been supplied sequentially according to a computer program. Since migration of species on the growth surface is enhanced, a very smooth surface is obtained with a terrace length of 330nm for SrTiO3 substrate and 660nm for NdGaO3 substrate. A high superconductivity critical current has been obtained from an ultrathin film of even 12nm thick.Josephson junctions were fabricated by irradiating YBaCuO films with 350keV electron beam. Magnitic field depedence of the critical current revealed that a very uniform junctions were obtained. Annealing at 400K improvedthe degradation problem with junctions. Fabrication of junctions using scanning probe microsccopes has also been investigated.Ultrathin films of silicon and germaniuim were prepared by atomic layr epitaxy using atomic hydrogen as reducer. A new method w … More as developed in which Si source gas of high pressure was confined in a reaction chamber. A conditionof ALE with one monomolecular layr per cycle was established. Atomic layr deposition of silicon oxide and nitride has also been investigated.Trench-oxide metal-oxide-semicconductor structure was proposed for silicon quantum wire devices. Electron confinement by trench MOS structure was simulated using a supercomputer. A sample device was fabricated using electron beam lithography and electron-cyclotron-resonance reactive ion etching method. A signal due to quantum effects is obtained in capacitance-voltage characteristics measured at ultralow temperature.Nanoccrystalline silicon with diameter less than 10nm was fabricated in a plasma cell of silane and hydrogen. Monodispersed particles were ontained by an idea of separating nucleation and crystal growth. Structure of nanocrystalline silicon was evaluated by atomic force microscopy and electron microscopy. Visible photoluminescence was observed at room temperature. Coulomb staircase phenomena, single electron tunneling effects, were observed in current-voltage characteristics from a nanocrystalline silicon at room temperature.Thinfilm transistors of amorphous and polycrystalline silicon were investigated. The mechanism of degradation, application of ultralarge scale integration and neural network were discussed. Less