离子注入Al0.25Ga0.75As/GaAs的Raman光谱研究

0.8 MeV的Si离子注入Al_0.25Ga_0.75As/GaAs外延薄膜的弱损伤特征.注入剂量从1×10¹⁴～5×10¹⁵ cm^-2,对注入后的样品采用了Raman光谱测量,观察到了两类声子模式,该外延材料的晶格振动显示出“双模”行为.并计算了在注入层中的应变以及晶格常数随剂量的变化.此外还测量了样品的Rutherford背散射和沟道谱(RBS/C),结果表明与Raman光谱测量一致的结论：该注入条件只引起材料的弱损伤行为.     

Extraction of optical constants and thickness of nanometre scale TiO2 film

TiOTiO2 薄膜 沉积物 磁电管喷射系统 X射线 发射光谱TiO₂ thin films, pointwise constrained optimization approach, constrained nonlinear programming, optical constants, parameters extractionProject supported by Shanghai Municipal Commission for Science and Technology (Grant No 03DZ14025) and National Basic Research Program of China (Grant No 2006CB300406).3/4/2005 12:00:00 AM2005-03-042005-07-28TiO2 thin films were deposited on glass substrates by sputtering in a conventional rf magnetron sputtering system. X-ray diffraction pattern and transmission spectrum were measured. The curves of refraction index and extinction coefficient distributions as well as the thickness of films calculated from transmission spectrum were obtained. The optimization problem was also solved using a method based on a constrained nonlinear programming algorithm.