不同种类表面活性剂对a面蓝宝石衬底CMP的影响

Effects of Different Kinds of Surfactants on the CMP of a-Plane Sapphire Substrates

研究了在抛光液中分别添加非离子表面活性剂异辛醇聚氧乙烯醚(JFCE)、阴离子表面活性剂十二烷基苯磺酸(LAS)和阳离子表面活性剂十二烷基三甲基氯化铵(DTAC)对a面蓝宝石衬底化学机械抛光(CMP)去除速率和表面状态的影响。通过对抛光液中磨料粒径和Zeta电位的分析可知,JFCE、LAS对粒径和Zeta电位影响不大,DTAC对粒径和Zeta电位有一定影响,当DTAC体积分数增加到0.5%时,抛光液中会出现凝胶现象。采用原子力显微镜、接触角检测仪对CMP后蓝宝石表面状态进行了分析和表征,结果表明,在一定浓度范围内三种表面活性剂均有助于提高蓝宝石去除速率和降低表面粗糙度,当其体积分数均为0.4%时,使用添加DTAC的抛光液时a面蓝宝石的去除速率最大、表面粗糙度最低,更有利于衬底表面的洁净化。

The effects of the slurry with the nonionic surfactant isooctanol polyoxyethylene ether(JFCE), anionic surfactant dodecylbenzene sulfonic acid(LAS) and cationic surfactant dodecyl trimethyl ammonium chloride(DTAC) on the chemical mechanical polishing(CMP) removal rate and surface state of the a-plane sapphire substrate were studied respectively. The analysis results of the abrasive particle size and Zeta potential of the slurry show that JFCE and LAS have little effect on the particle size and Zeta potential, while DTAC has a certain effect on the particle size and Zeta potential of the slurry. When the volume fraction of DTAC is increased to 0.5%, gelation occurs in the slurry. The surface state of sapphire after CMP was analyzed and characterized by atomic force microscope and contact angle detector. The results show that the three surfactants can improve the removal rate and reduce the surface roughness of a-plane sapphire within a certain concentration range. When the volume fraction of the three surfactants is 0.4%, the removal rate of sapphire is the highest and the surface roughness of the sapphire is the lowest when the slurry was added with DTAC, which is more conducive to the cleanliness of the substrate surface.