FUNDAMENTAL RESEARCH FOR QUANTUM DEVICES CONSTRUCTED WITH MULTI-LAYERS OF VERY THIN EPITAXIAL Al2O3 AND Si

用多层极薄外延 Al2O3 和 Si 构建的量子器件的基础研究

基本信息

批准号：
10450118
负责人：
ISHIDA Makoto
金额：
$ 2.05万
依托单位：
TOYOHASHI UNIVERSITY OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10450118/
关键词：
SOI structures epitaxial Al2O3 film MBE method epitaxial growth thin Si film quantum device resonant tunnel 薄膜シリコン

项目摘要

Heteroepitaxial growth of insulating layers on Si and the successive growth of a single crystalline Si on those insulating layers are of great interest in the formation of silicon-on-insulator (SOI) structures. We have proposed γ-Al2O3 films as an insulator material and obtained high quality layers of γ-Al2O3 on Si substrates. In our group, we have already studied SOI(Silicon On Insulator) structures, and have proposed an epitaxial γ-Al2O3 film as insulator material. The epitaxial growth of γ-Al2O3 was investigated with the hybrid source MBE using Al solid source and N2O gas source. Very thin and very flat γ-Al2O3 films without carbon contamination were grown on Si substrates successfully by the hybrid source MBE.This structure is suitable for the usual Si process due to stable Al2O3 insulator. So γ-Al2O3 is being expected of an insulation film which can be substituted for SiO2. At present, our group are studying application to MIS type Field Emitter of γ-Al2O3. Furthermore, applicatio … More ns to quantum effect devices can be expected because multiple layer structure by Si and γ-Al2O3 can be formed easily. The very thin film growth control of γ-Al2O3 and Si becomes very necessary to form a quantum well structure. Therefore, the purpose of this study is the growth control of nm-thickness, and the formation of the quantum well structure by Si and γ-Al2O3. The quantum well structure composed of Si and an insulation film can be expected to lock up electrons of the high energy, because an insulation film with a large barrier height to Si was used. So the quantum well structure by Si and γ-Al2O3 has a potential application to an emitter which can emit a constant electron energy. As a result of the calculation, the thickness control of the Si film in less than 4nm must be realized. As growth of γ-Al2O3, an electrical insulation property of directly grown γ-Al2O3 on the Si was poor. But about 5MV/cm was realized using a 3nm-thick γ-Al2O3, which was prepared by Al2O3 pre-layer method. The γ-Al2O3 growth control of very thin film (3nm-thick) with good insulation property was realized by this growth method. Until now, Si2H6 gas sauce was used for the Si growth, but the control of film thickness of a few nm was impossible. So, the Mini-beam evaporator device with a low growth rate was introduced. So low speed growth (4nm/hour) became possible by this method. But a problem in Si surface flatness was still remained. So we proposed that termination of a γ-Al2O3 surface with Al, which is at first, deposition of Al, then annealing with 800℃. By this method, at the early stage of the Si growth, we succeeded in the repression of three-dimensional growth of Si. A γ-Al2O3 (3nm) /Si (lll) (4nm)/γ-Al2O3 (3nm)/Si (lll) structure was formed with Al2O3 pre-layer and Al pre-deposition. Then, the electrical characteristics were evaluated. As a result, a negative resistance was confirmed at room temperature. Less

Si 上绝缘层的异质外延生长以及这些绝缘层上单晶 Si 的连续生长对于绝缘体上硅 (SOI) 结构的形成非常重要。我们提出了 γ-Al2O3 薄膜作为绝缘体材料和材料。在Si衬底上获得了高质量的γ-Al2O3层。我们课题组已经研究了SOI（绝缘体上硅）结构，并提出了一种外延结构。 γ-Al2O3 薄膜作为绝缘体材料，采用 Al 固体源和 N2O 气体源的混合源 MBE 进行了研究，成功地在 Si 衬底上生长了非常薄且非常平坦的无碳污染的 γ-Al2O3 薄膜。由于具有稳定的Al2O3绝缘体，该结构适用于通常的Si工艺，因此γ-Al2O3有望成为可以替代的绝缘膜。目前，我们小组正在研究γ-Al2O3在MIS型场发射器中的应用，并且由于可以容易地形成Si和γ-Al2O3的多层结构，因此有望应用于量子效应器件。为了形成量子阱结构，γ-Al2O3和Si的极薄膜生长控制变得非常必要，因此，本研究的目的是纳米厚度的生长控制，以及Si形成量子阱结构。由Si和绝缘膜组成的量子阱结构由于使用了对Si具有较大势垒高度的绝缘膜，因此有望锁定高能量的电子。计算结果表明，γ-Al2O3在发射恒定电子能量的发射极方面具有潜在的应用前景，随着γ-Al2O3的生长，必须实现Si薄膜的厚度控制在4nm以下。在Si上直接生长γ-Al2O3的性能较差，但使用Al2O3预层法制备的3nm厚的γ-Al2O3实现了非常薄的γ-Al2O3生长控制。通过这种生长方法，实现了具有良好绝缘性能的3nm厚的Si2H6气体酱，但无法控制几nm的膜厚。因此，引入了低生长速率的迷你束蒸发器装置，因此通过该方法可以实现低速生长（4nm/小时），但仍然存在Si表面平整度的问题，因此我们提出终止γ。 -Al2O3表面带有Al，即首先沉积Al，然后进行800℃退火，通过这种方法，在Si生长的早期阶段，我们成功地抑制了Si A的三维生长。用Al 2 O 3 预层和Al预沉积形成γ-Al 2 O 3 (3nm)/Si(IIII)(4nm)/γ-Al 2 O 3 (3nm)/Si(IIII)结构，然后评价电特性。结果，在室温下确认了负电阻。