射频功率对富硅-氮化硅薄膜结构及性质影响

Effect of Radio-frequency Power on Bond Structures and Properties of Silicon-rich Silicon Nitride Thin Films

采用等离子体增强化学气相沉积法,以SiH_4、NH_3和N_2为反应气源,通过改变射频功率制备富硅-氮化硅薄膜材料。利用傅里叶变换红外吸收光谱,紫外-可见光透射光谱,扫描电镜等对薄膜材料结构与性质进行表征。实验表明,随着射频功率的逐渐增加,薄膜光学带隙缓慢减小、有序度增加,薄膜材料中的Si-H键、N-H键缓慢减小,Si-N键增多。分析结果发现,适量的增加射频功率有利于提高样品反应速率,使薄膜有序度增加,致密性增强,提高薄膜质量,但过高的射频功率会使薄膜质量变差。

Silicon-rich silicon nitride thin films were deposited by plasma enhanced chemical vapor deposition method using SiH4, NH3 and N2 as reaction gas source with changing of radio-frequency power. The structures and properties of the thin film materials were characterized by Fourier transform infrared absorption spectroscopy, ultraviolet-visible transmission spectra and S E M , respectively. T h e results show that with radio-frequency power increasing, the bandgap of the film materials decrease slowly, the order degree of films improve gradually, and the Si-N, N-H bonds in the thin films decrease, with increasing of the Si-N bonds gradually. Analysis of the results find that properly increasing radio-frequency power is beneficial to the enhancing of the ion reaction rate in thin films, the improving of film order degree, the enhancing of thin film compactness, the getting better of thin film quality. But the outrageous radio-frequency power will damage thin film quality.