利用PECVD在硅片上沉积了氮化硅(SiNx)薄膜,将沉积膜后的样品放在№气氛中进行快速热处理(RTP),研究了不同快速热处理对PECVD氮化硅薄膜性能的影响。采用原子力显微镜(AFM)检测薄膜的表面形貌,利用椭圆偏振仪测量样品膜厚和折射率,利用准稳态光电导衰减法(QSSPCD)测量样品的少子寿命。实验结果表明随着RTP温度的升高,薄膜厚度迅速减小,折射率迅速增大;低于500℃热处理时,少子寿命基本不变;高于500℃热处理时,随着温度的升高,少子寿命急剧下降。氮化硅薄膜经热处理后反射率基本不变。
SiNx thin films were deposited on silicon wafer by PECVD,then,rapid thermal processing(RTP) was performed to the silicon wafer at different temperature in N2 ambience. The characteristics of the thin films after RTP were investigated by atomic force microscope(AFM) and spectral ellipsometry. The results indicate that with the increasing of temperature, the thickness of the thin films decreases and the refractive index increases, and the reflectance of the thin films keeps constant after RTP. The minority carrier lifetime of the wafer was measured by quasi steady state photoeonductance decay (QSSPCD) ,the data reveal that the minority carrier lifetime keeps almost invariable below 500 ℃, and decreases quickly with increasing temperature above 500 ℃.