Abstract
ABSTRACTAsymmetric Surface X-Ray Diffraction of Nanometer Silicon LinesChia-Cheng Lin, Advisor : Professor Shih-Lin ChangMaster of Physics,National Tsing Hua University, Taiwan, Republic of China This work aims to develop a kind of nanometer silicon lines which allow wide-angle incident X-rays to propagate in a special direction, say the [113] of Si, the so-called waveguiding effect. Moreover, this nanometer silicon line can be used to exhibit the single-slit diffraction phenomenon and multiple-mode interference of the ( 1 1 3 ) dynamical diffraction. Nanometer silicon lines about 1μm high, 4mm long along [110], and 350nm to 20um wide were prepared by the Nano Device Laboratory (NDL) on a 4 inches silicon [001] waver. The lines were then covered by 150nm thick gold film. The ( 113 ) diffraction beam propagates along the surface of the waver at the photon energy 8.8785kev. The propagation direction is also along the [110]. The diffraction experiments show that X-rays can be guided within the nanometer silicon lines, but with a very low guiding efficiency due to crystal absorption. Most importantly, the single-slit diffraction phenomenon and multiple-mode interference of the (113) reflection are clearly observed. The dynamical theory of X-ray diffraction in the Cartesian coordinate representation is employed to analyze the X-ray wavefield in the silicon crystal and to account for the interference phenomenon.