Ar流量对ECR-PECVD制备氢化纳米晶硅薄膜结构及性能影响研究

Influence of Argon Flow Rate on Structure and Properties of Hydrogenated Nanocrystalline Silicon Films Prepared by ECR-PECVD

采用电子回旋共振等离子体增强化学气相沉积(ECR-PECVD)设备制备了氢化纳米晶硅薄膜。通过Raman光谱、XRD和紫外-可见分光光度计的测试分析,研究了Ar/H2对薄膜组织结构和光学性能的影响,并对沉积腔室的等离子体环境进行了系统的诊断。实验发现:少量Ar气的通入有利于提高腔室中的电子温度,保证纳米晶硅薄膜结构的同时提高薄膜的光学带隙宽度。进一步提高Ar气的比例,薄膜明显非晶化,光学性能下降。结合薄膜生长机理和放电气体电离特性对实验结果的产生原因进行了分析。

Hydrogenated nanocrystalline silicon films （nc-Si： H ） were prepared by electron cyclotron resonance plasma-enhanced chemical vapor deposition （ECR-PECVD）. The effect of Ar/H2 ratio on the structure and optical properties of as-grown nc-Si： H films was investigated systematically with Raman scattering, XRD as well as ultraviolet-visible spectrometer. The electron temperature （ To ） in the reaction chamber was diagnosed by Langmuir probe and optical emission spectroscopy （OES）. The results indicated that a moderate amount of Ar introduced into the H2 plasma could increase the Te and enhance the optical properties of the films. Finally, the microscopic mechanism of the effect was elucidated based on the ionization characteristics of reactant gases and the results of plasma diagnosis.