应用高频激励源制备低应力氮化硅薄膜研究

Study on Low Stress Silicon Nitride Deposited by PECVD with High Frequency

研究了在等离子体增强化学气相沉积(PECVD)法制备氮化硅薄膜时,射频功率和腔室压力对氮化硅薄膜应力的影响以及应力与沉积速率的关系。通常认为高频下制备得到的氮化硅膜呈现张应力,但是通过实验,表明即使应用高频(13.56MH z)作为激励源同样可以沉积出呈现压应力的氮化硅薄膜。并使用角度可变光谱型椭偏仪观察了薄膜的厚度和低应力氮化硅膜的m app ing图,利用傅立叶变换红外光谱仪(FT IR)对不同应力状态下的氮化硅膜的化学键结构进行了分析。

We studied the relationship between the RF power, the chamber pressure and the film stress for deposited the silicon nitride film by Plasma Enhance Chemical Vapor Deposition （PECVD）. It shows that even if using the RF power（13.56 MHz） as the excitation of plasma, the compressive silicon nitride film can be obtained easily. The low stress film shows the good uniformity through the mapping measurement by variable angle spectroscopic ellipsometry （VASE）. The silicon nitride films chemical composition was analyzed by FTIR （Fourier Transform Infrared Spectroscopy）.