Ar环境气压对纳米Si晶粒成核区范围的影响

为了研究不同环境气压条件下纳米Si晶粒成核区的范围,采用波长为308 nm的 XeCl脉冲准分子激光器,分别在1-200 Pa的Ar气环境下, 烧蚀高阻抗单晶Si靶,在距离烧蚀点正下方2.0 cm处水平放置一系列单晶Si 或玻璃衬底,沉积制备了纳米Si薄膜. Raman谱和X射线衍射谱测量证实了薄膜中纳米Si晶粒已经形成. 扫描电子显微镜的测量结果表明,环境气压的变化影响了衬底上纳米Si晶粒的平均尺寸及其分布范围. 根据成核区位置的确定方法,计算得出随着环境气压的增加纳米Si晶粒成核区的范围先变宽后变窄的规律. 从烧蚀动力学的角度对实验结果进行了分析.

Influence of the ambient pressure of Ar on the range of nucleation area of Si nanoparticles

In order to investigate the range of nucleation area of Si nanoparticles under different pressures, a single crystalline Si target with high resistivity is ablated by a XeCl excimer laser (wavelength 308 nm, laser fluence 3 J/cm²) in an ambient pressure range from 1 to 200 Pa of pure Ar gas. The Si nanocrystalline films are systemically deposited on glass or single crystalline Si substrates that are lined up at a distance of 2.0 cm under the ablation point. Raman and X-ray diffraction spectra indicate that the films are nanocrystalline. Scanning electron microscope images of the films show that the ambient pressure effect on the average size and the distributing range of Si nanoparticles on the substrate. According to the method of determining the location of nucleation area, it is found that the range of nucleation area of Si nanoparticles first broadens and then narrows with the increase of ambient pressure. The dynamics is analysed theoretically to explain the results.