PECVD沉积和原位退火时间对h-BN薄膜组成及光学带隙的影响

Influence of Deposition and in situ Annealing Time on Composition and Optical Band Gap of h-BN Films Deposited by PECVD

采用射频等离子增强化学气相沉积设备,以高纯N2和B2H6为气源,制备了系列h-BN薄膜,得到适合生长h-BN薄膜的最佳工艺条件。在此条件下,研究了不同沉积时间和退火时间对薄膜组成和光学带隙的影响。采用傅立叶变换红外光谱仪、紫外可见光分光光度计和场发射扫描电子显微镜对样品进行了表征。实验结果表明:在衬底温度、射频功率和气源流量比率一定的条件下,沉积时间对h-BN薄膜成膜质量和光学带隙都有较大影响,且光学带隙与膜厚呈指数关系变化。700℃原位退火不同时间对h-BN薄膜的结晶质量有所影响,而物相和光学带隙基本没有改变。

Series of h-BN films were grown by RF plasma enhanced chemical vapor deposition （PECVD） tech- nique using high purity nitrogen and diborane as the precursor gases. The optimized experimental conditions for preparing h-BN films were explored. Based on these explorations, influences of deposition time and in situ anneal- ing time on the composition and optical band gap of the films were investigated. All specimens were characterized by Fourier transform infrared spectroscope, utraviolet-visible spectrophotometer and field emission scanning electron mi- croscope. The results show that the deposition time has a significant impact on the quality and optical band gap of the samples, and the optical band gap exhibits an exponential relation with the varied thickness of the films. Moreover, in situ annealing at 700℃ can affect the crystal quality, but almost not the phase and optical band gap of the h-BN films.