采用XeCl脉冲准分子激光器 ,烧蚀高阻抗单晶Si靶 ,在 1— 5 0 0Pa的Ar气环境下沉积制备了纳米Si薄膜 .x射线衍射谱测量证实 ,纳米Si晶粒已经形成 .利用扫描电子显微镜观测了所形成纳米Si薄膜的表面形貌 ,结果表明 ,随着环境气压的增加 ,所形成的纳米Si晶粒的平均尺寸增大 ,气压为 10 0Pa时达到最大值 2 0nm ,而后开始减小 .从晶粒形成动力学角度 ,对实验结果进行了定性分析 . Nanocrystalline Si films were deposited by XeCl pulsed excimer laser ablation and high-impedance single-crystal Si target deposition under Ar atmosphere at 1 -500 Pa. The X-ray diffraction spectrum measurement confirmed that nanostructured Si grains had been formed. The surface morphology of the nanostructured Si thin films was observed by SEM. The results showed that with the increase of ambient pressure, the average size of the formed nano-Si grains increased and reached the maximum value of 20 nm at 10 0 Pa, Decrease.From the perspective of grain formation kinetics, the experimental results were qualitatively analyzed.