雾化施液CMP抛光硅片的亚表层损伤研究  

Detection of Subsurface Damage of Wafer Polished by Ultrasonic Atomization CMP

作　　者：壮筱凯 李庆忠 

机构地区：[1]江南大学机械工程学院,无锡214122

出　　处：《硅酸盐通报》2015年第8期2291-2297,共7页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金项目(51175228)

摘　　要：雾化施液CMP抛光后的硅片依然存在亚表层损伤,会严重影响硅片的使用性能。首先利用化学腐蚀法和光学显微镜分别观测了亚表层的微裂纹以及不同部位的位错蚀坑形貌和位错密度。然后利用显微共聚焦拉曼光谱仪分析了抛光前后硅片表面残余应力的变化行为以及应力的分布情况。最后利用差动蚀刻速率法测取了亚表层的损伤深度并分析了抛光参数对损伤深度的影响规律。研究表明:随着表层到亚表层深度的增加,微裂纹损伤愈加严重,硅片边沿处的位错密度和形貌要明显好于中心区,位错平均密度为1.2×104/cm2;雾化抛光后的硅片表面被引入残余拉应力,应力沿硅片对角线方向呈对称分布;亚表层的损伤深度大约为0.99μm,随着雾化器电压的增大呈递减趋势,而抛光垫转速和抛光压力都存在一个最佳的参数使损伤深度达到最小。Subsurface damage （SSD） may still exists in wafer which had been polished by ultrasonic atomization chemical mechanical polishing（CMP） and it will have an adverse influence on performance. Firstly, the micro-crack and dislocation etch pit in different positions were observed by chemical etch method and microscope. Then, the change and distribution of residual stress of wafer which had been polished were measured with raman spectrometer. Finally, the SSD was measured by differential etch rate method and influence of process parameters on SSD was studied by single factor experiment. The results show that the micro-crack become worse when the subsurface depth increases and dislocation morphology in edge area is better than middle area. The average density is about 1.2 × 10^4/cm2. Besides, wafer after polished was added residual tensile stress and the stress distributes symmetrically along the diagonal direction. In addition, the SSD is about 0.99 μm and it could be reduced by increase the voltage of atomization. However, both the speed of polishing pad and polishing pressure has a best parameter to get the minimum SSD.

关 键 词：雾化施液 位错 微裂纹 残余应力 亚表层损伤深度 

分 类 号：TN305[电子电信—物理电子学]