Study on stacking fault by oxigen in Czochralski Si-wafer by means of 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，制备了在约5 X 10 - 15 Torr的氧气气氛中沉积的具有颗粒结构的铝薄膜<-6>，并且这些用于搅拌器（声子发生器）和测辐射热计（接收器）。为了获得高的空间分辨率，采用了光刻技术，即加热器和测辐射热计的尺寸约为48 × 48 mum^2，以避免由于非常窄的（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。由于氧引起的堆垛层错与氧原子浓度有关，本研究以CZ（Czocbralski）法和FZ（Floating Zone）法两种不同氧浓度（5 × 10 ^ /cc和5 × 10 ^ /cc）的硅片为样品，采用数值分解技术消除了有限的热容量和电容量引起的信号延迟<16><17>。将这些样品的两端抛光，厚度约为500 μ m。将加热器和测辐射热计放置在相对的表面上，通过探测穿透的脉冲声子来测量声子脉冲散射，明确了引起层错的氧原子的存在对声子脉冲穿透非常敏感，即T模式与L模式的比率。模式信号峰高和扩散声子峰的形状强烈地依赖于氧浓度和晶片制备方法。但理论分析和定量分析仍需继续。

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 X l0^<-6> Torr were prepared, and these were used for both beater (phonon generator) and bolometer(receiver). For high space resolution, a photolithography technique was employed, namely the size of heater and bolometer was about 48X48 mum^2 to avoid the electromagnetic induct ion(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 decombolution technique.In the present investigation, as the stacking faults caused by oxegen dependon the consentration of oxygen atoms, two kinds of Si wafers with different oxygen consentration(5X10^<16>/cc and 5x10^<17>/cc) by CZ(Czocbralski)method Si wafer and FZ(Floating zone)method Si wafer which contains far less oxygen were used as sample. The both ends of these samples were polished and the thickness was about 500mum. The heaters and bolometers were deposited onto opposite faces, and phonon pulse scattering was measured by detecting the penetrated pulse phonons.It was made clear that the existence of oxygen atoms which cause stacking faults is very sensitive to the phonon-pulse penetration, namely the ratio of T-mode to L-mode signal peak hights and also the shape of diffused phonon peaks were strongly depending on the oxygen consentartion and the method of wafer preparation. But the theoretical and quantitative analysis should be continuted.