A Study of High-Functional Material System for Opto-Electronic Integrated Devices with Metal/Insulator Heterostructure Superlattices

本项目旨在利用硅衬底上的金属/绝缘体/半导体超晶格，构建由电子器件、光学器件和光电器件组成的高性能集成电路。为了实现这种集成电路，我们实现了CaF_2/CdF_2和Si/CaF_2超晶格的良好控制外延生长，由于它们具有非常高的频带偏移，因此具有显着的量子效应，适合于高功能器件。然后，我们用这些超晶格制造谐振隧道器件，并将超短通道肖特基源/漏极mosfet与谐振隧道器件集成。对于外延生长及其在谐振隧道器件中的应用，我们采用离子束外延技术建立了生长条件，得到了负差分电阻峰谷比高达10^5的谐振隧道二极管。利用SiO_2掩模在硅衬底上选择性生长成几百纳米尺寸的窗口，进一步提高了外延层的晶体质量。该方法在室温下获得了均匀性高、重现性好、峰谷比大的谐振隧道二极管。采用PtSi和ErSi_2分别制备了具有肖特基源极和漏极的超短沟道mosfet。器件的通道长度短至25nm，可在室温下运行。通过使用带有薄硅层的SOI衬底，可以提高开/关比。作为一种适合与谐振隧道二极管集成的晶体管结构，制作了垂直肖特基源极/漏极p- mosfet，并在室温下实现了沟道宽度为8nm、沟道长度为50nm的器件的晶体管作用。通过这些结果，我们认为建立了硅衬底上高功能量子效应器件及其集成电路的基本元件的制造工艺和基本操作。少

This project aimed at constructing high-functional integrated circuits composed of electron devices, optical devices, and opto-electronic devices utilizing metal/insulator/semiconductor superlattices on silicon substrates. In order to realize such integrated circuits, we achieved well controlled epitaxial growth of CaF_2/CdF_2 and Si/CaF_2 superlattices which are suitable for high-functional devices due to their very high band offsets resulting in remarkable quantum effects. We then fabricated resonant tunneling devices with these superlattices, and ultra-short channel Schottky source/drain MOSFETs to be integrated with the resonant tunneling devices.For the epitaxial growth and its application to resonant tunneling devices, we established the growth condition by using ionized beam epitaxial technique, and obtained resonant tunneling diodes with the peak-to-valley ratio of the negative differential resistance as high as 10^5. The crystalline quality of the epitaxial layers were further … More improved by a selective growth into windows with a few hundred nanometer size made on silicon substrate by SiO_2 masks. By this method resonant tunneling diodes with high uniformity, reproducibility, and large peak-to-valley ratio were obtained at room temperature.Ultra-short channel MOSFETs with Schottky sources and drains were fabricated with PtSi for p-type and ErSi_2 for n-type devices. Room-temperature operation of the devices with the channel length as short as 25nm was achieved. On/off ratio was shown to be increased by the use of SOI substrates with the thin silicon layers. As a transistor structure suitable for integration with the resonant tunneling diodes, vertical Schottky source/drain p-MOSFETs were fabricated, and transistor action was achieved at room temperature for the devices with channel width 8nm and channel length 50nm. By these results, we believe that fabrication process and fundamental operation of the basic elements for high-functional quantum-effect devices and their integrated circuits on silicon substrates were established. Less