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

东京工业大学用金属有机化学气相沉积法在500 ℃的低温下成功地制备了氧化物超导体YBaCuO超薄膜。在厚度为3.6nm（3个晶胞厚度）的薄膜中观察到了超导起始。在MgO衬底上，厚度为4. 8 nm的样品在30 K时电阻率为零，厚度为10 nm的样品在80 K时电阻率为零。这些结果表明，我们已经沉积了最高质量的薄膜。我们还发现，迁移的化学物种的YBaCuO薄膜的晶体生长过程中的原子层-层的方法增强。用原子力显微镜观察到YBaCuO薄膜表面非常光滑，粗糙度小于一个单位晶胞厚度沿着10 μ m范围。微桥结构的临界电流密度高达10^7Acm^<-2>。剑桥大学用350 KeV电子辐照YBaCuO薄膜制备了约瑟夫森结 ...更多信息 梁用二氯硅烷和氢自由基在原子层外延上制备了硅的超薄膜，用有机锗和氢自由基在原子层外延上首次制备了锗的超薄膜，用沟道氧化物金属氧化物薄膜制备了硅的超薄膜，用硅的超薄膜制备了硅的超薄膜。半导体结构被提出用于来自东京工业大学的硅量子线器件。用超级计算机模拟了沟槽MOS结构的电子约束。然后评估了在低温下从电容-电压特性可观察到量子效应。采用电子束光刻和电子回旋共振反应离子刻蚀的方法制作了沟槽MOS的实际器件。在0.5K下，从一个宽为28 nm的沟槽样品中观察到了量子效应结构。研究发现，氢自由基在纳米硅的形核和晶体生长过程中起着重要的作用。结果表明，氢自由基对选择性腐蚀纳米晶硅周围的非晶硅也是有用的，可以用来制造有效的势垒层。东京工业大学和剑桥大学都对非晶硅和多晶硅薄膜晶体管进行了研究。讨论了降解机理、超大规模集成和神经网络的应用。少

Ultrathin films of oxide superconductors YBaCuO have been prepared successfully at a temperature of as low as 500^ﾟC by metalorganic chemical vapor deposition method at Tokyo Institute of Technology. Superconductivity onset was observed from a film of as thin as 3.6nm(3 unit-cell-thickness). Zero-resistivity at 30K was observed from 4.8nm-thick sample and 80K was observed from 10nm-thick YBaCuO on MgO substrate. These results suggest that we have deposited the highest quality films. We have also revealed that migration of chemical species were enhanced during the crystal growth of ultrathin films of YBaCuO by atomic layer-by-layer method. Very smooth surface of YBaCuO films with roughness of less than one unit-cell-thickness along 10 mum range was observed by atomic force microscopy. A critical current density of as high as 10^7Acm^<-2> was obtained from a microbridge structure. Josephson junctions were fabricated at Cambridge University by irradiating YBaCuO films with 350KeV electron … More beam. Magnetic field dependence of the critical current revealed that very uniform junction was obtained.Ultra-thin films of silicon were prepared by atomic layer epitaxy by using dichlorosilane and hydrogen radicals at Tokyo Institute of Ultra-thin films of Ge were also prepared by atomic layer epitaxy for the first time by using organicgerman and hydrogen radicals.Trench-oxide metal-oxide-semiconductor structure was proposed for silicon quantum wire devices from Tokyo Institute of Technology. Electron confinement by the trench MOS structure was simulated by using a supercomputer. It was then evaluated that quantum effects would be observable from the capacitance-voltage characteristics at low temperatures. Actual device of trench-MOS was fabricated by using electron beam lithography and electron cyclotron resonance reactive ion etching method. A structure due to quantum effects was observed from a sample with 28nm-wide trench at 0.5K.Digital chemical vapor deposition method was proposed for the fabrication of Si quantum dot structure from Tokyo Institute of Technology. It was found that hydrogen radicals played very important role both in the nucleation and crystal growth of nanocrystalline silicon. It turned out that hydrogen radicals were also useful for theselective etching of amorphous silicon surrounding nanocrystalline silicon for the fabrication of effective potential barrier layer.Thin film transistors of amorphous and polycrystalline silicon were investigated both at Tokyo Institute of Technology and Cambridge University. The mechanism of degradation, application of ultra-large scale integration and neural network were discussed. Less