Study of Scattering Process in Tunnel-Device by Phonon Pulse.

在目前的研究中，最重要的和必不可少的技术，必须完成的是热脉冲（声子脉冲）技术，在空间和时间上具有极高的分辨率和灵敏度。为此目的，制备了在约5 X 10 - 2 Torr的氧气气氛中沉积的具有粒状结构的铝薄膜<-6>，并且这些用于加热器（声子发生器）和测辐射热计（接收器）。为了获得高空间分辨率，采用了光刻技术，即加热器和测辐射热计的尺寸约为48*48 μ ^2。避免了电磁感应（击穿）引起的极窄（几纳秒）脉冲电流，加热器和测辐射热计彼此垂直设置，并使用微同轴电缆。用数值解卷积技术消除了由有限的热容量和电容量引起的信号延迟.在本研究中，明确了在MBE法制作的隧道器件中，Si基区和SiGe膜之间的边界处的晶体变形引起了大的声子散射和声子模式转换，即使在小于100埃的很薄的区域也是如此.该方法对于研究小区域的晶体形变是非常灵敏和有用的，此外，为了扩展这一研究，我们用氢等离子体溅射方法在Si衬底上外延生长了SiC薄膜，同时也清楚地表明，3C-SiC薄膜是在800 ℃的低温下外延生长到Si晶片上的，然后我们想继续使用3C-SiC薄膜进行这项研究。

In the present research, the most important and indispensable technology which must be accomplished is the heat-pulse(phonon-pulse) technology with ultimate high resolution in space and time, and sensitivity. For this purpose, aluminium thin'films with granular structure deposited in oxygen gas atmosphere of about 5 X10^<-6> Torr were prepared, and these were used for both heater(phonon generator)and bolometer(receiver). For high space resolution, a photolithography technique was employed, namely the size of heater and bolometer was about 48*48 mu^2. To avoid the electromagnetic induction(break-through) caused by a very narrow(a few nano-sec.) pulse current, the heater and the bolometer were set vertically to each other, and micro coaxial-cable was used. The signal delay caused by finite heat and electric capacities were removed by numerical decoinbolution technique.In the present investigation, it was made clear that a crystal deform at boundaries between Si base and SiGe films in a tunneling-device preparedi by MBE method gives rise to a large phonon scattering and a phonon mode conversion even by very thin regions less than 100 A.namely, this method is very sensitive and useful to investigate the crystal deform of small region.Furthermore, to expand this investigation, an epitaxial growth of SiC film on-to Si base was carried out by means of hydrogen plasma sputtering method, and it was also made clear that 3C-SiC film was epitaxially grown onto Si wafer at a surprising low temperature, 800ﾟC, and then we would like to continue this in-vestigation using 3C-SiC films.