摘要
研究了阻挡层在化学机械抛光过程中表面活性剂的作用。利用5种活性剂体积分数不同的抛光液对3英寸(1英寸=2.54 cm)Cu/Ta/SiO2光片进行抛光。通过抛光前后质量变化可得各晶圆片的抛光速率,再对12英寸布线晶圆片进行抛光,利用台阶仪测量抛光前后碟形坑大小的变化,最后利用原子力显微镜对抛光后布线晶圆片的表面形貌进行测试。研究表明抛光液中活性剂体积分数不同会引起抛光速率的变化,也会影响碟形坑的修正效果。当抛光液中活性剂体积分数达到2.0%时,修正值达到85.6 nm/min,优于其他活性剂体积分数时的修正值。另外,活性剂体积分数的增加有助于降低抛光后晶圆表面的粗糙度。活性剂体积分数小于3.0%时,粗糙度随着活性剂体积分数的增加而降低。这一发现可以对配制抛光液时活性剂体积分数的确定起到一定的参考作用。
The effect of the surfactant during the process of CMP for the barrier layer was stu- died. The Cu/Ta/SiO2 wafers of 3 inches （1 inch = 2.54 era） were polished by five slurries with different volume fractions of the surfactants. The removal rates of all wafers were obtained through the weight change before and after CMP. Then, the 12 inches pattern wafers were also polished with the slurries above. The changes of the dishing height before and after CMP were measured by the surface profiler. Finally, the surface topographies of the pattern wafers after CMP were measured by AFM. The researches show that different volume fractions of the surfactants induce the change of removal rate, as well as affect the correction effect of the dishing. When the volume fraction of the surfaetant in the polishing slurry reaches 2.0%, the correction value reaches 85.6 nm/min and is better than others. In addition, the increase of the volume frac tion of the surfactant is helpful to reduce the surface roughness of the wafer after CMP. When the volume fraction of the surfactant is less than 3.0%, the roughness decreases with the increase of the volume fraction of the surfaetant. This study may play a certain reference in determining the volume fraction of the surfaetant for preparing polishing slurries.
出处
《微纳电子技术》
CAS
北大核心
2014年第9期605-609,共5页
Micronanoelectronic Technology
基金
河北省自然科学基金资助项目(E2014202147)
关键词
表面活性剂
阻挡层
化学机械抛光(CMP)
速率选择性
碟形坑
粗糙度
surfactant
barrier layer
chemical mechanical polishing （CMP）
rate selectivity
dishing
roughness dishing
roughness
