衬底加温和后续热退火法形成纳米硅晶粒成核势垒的比较

在真空环境中,采用脉冲激光烧蚀技术,分别在衬底加温和室温条件下沉积制备了纳米Si薄膜.对在室温条件下制备得到的非晶Si薄膜,采用后续热退火实现其晶化.通过扫描电子显微镜、Raman散射仪和X射线衍射仪对制备的薄膜形貌、晶态成分进行表征,得到两种情况下纳米Si晶粒形成的阈值温度分别为700 ℃和850 ℃,通过定量计算比较了两种情况下晶粒成核势垒的大小,并从能量角度对阈值温度的差别进行了理论分析.

Comparison of nucleation energy of nanoparticles Si formation in substrate heating and subsequent thermal annealing

In vacuum environment, the nano-crystalline silicon films were prepared by pulsed laser ablation at high temperature and room temperature respectively. The amorphous films prepared under normal temperature were thermal-annealed, which leads to crystallization. The morphology and compositon etc. of the samples were characterized by scanning electron microscopy, Raman scattering and X-ray diffraction. The results showed that the temperature threshold of Si nanoparticles formation was 700 ℃ and 850 ℃ respectively. The nucleation energy of the nanoparticles was obtained by quantitative calculation, and the reason of difference between the temperature threshold was discussed from the point of view of energy.