摘要
以采用改进无皂乳液聚合法制备的纳米尺寸聚苯乙烯（PS）微球为内核,采用原位化学沉淀法制备了不同壳层厚度的PS/CeO2核/壳包覆结构复合微球。将所制备的复合颗粒用于二氧化硅介质层的化学机械抛光,用原子力显微镜测定晶片的微观形貌和粗糙度。电镜结果表明：复合颗粒呈规则球形,其PS内核尺寸约为72 nm,CeO2壳厚为5-20 nm。抛光结果显示：在本实验范围内,抛光速率随抛光压力的增加而增大,而过低（2.4 psi,1 psi=6 895 Pa）或过高（6.1 psi）的抛光压力均使晶片表面产生划痕。当抛光压力适中（4.5 psi）时,经复合磨料（壳厚约为13 nm）抛光后的晶片表面无明显划痕,在5μm×5μm范围内表面均方根粗糙度为0.265 nm,抛光速率达98.7 nm/min。
The PS-core/CeO2-shell composite microspheres with different controlled shell thicknesses were synthesized by the in-situ chemical precipitation technique based on the nanopolystyrene（PS）microsphere cores prepared by the modified soap-free emulsion polymerization.The as-prepared composite particles were used as abrasives for the oxide chemical mechanical polishing process.The morphology and surface roughness of the wafer were characterized by the atomic force microscopy.The TEM and SEM results show that the obtained PS/CeO2 composites are spherical,and the PS core is about 72 nm while the CeO2 shell thickness is 5-20 nm.The polishing test results indicate that the material removal rate increases with the increase of the polishing pressure under the experiment conditions.Besides,a lower（2.4 psi,1 psi=6 895 Pa）or higher（6.1 psi）polishing pressure results in scratches on the surfaces of the substrates.The surfaces without scratches can be obtained after polished with the composite abrasive（about 13 nm in shell thickness）under the moderate polishing pressure of 4.5 psi,and the roughness and material removal rate values in the range of 5μm×5μm are 0.265 nm and 98.7 nm/min,respectively.
出处
《微纳电子技术》
CAS
北大核心
2015年第2期129-134,共6页
Micronanoelectronic Technology
基金
国家自然科学基金资助项目(51205032)
江苏省自然科学基金资助项目(BK2012158)
