不同粒径纳米二氧化硅磨料对蓝宝石CMP去除机制的影响

Removal mechanism of sapphire during CMP using nano-silica abrasives with different sizes

采用不同粒径的纳米二氧化硅磨料对蓝宝石晶圆进行化学机械抛光(CMP)。结合实验与量子化学参数的仿真计算,研究了磨料粒径对抛光后蓝宝石晶圆表面性能的影响及其材料去除机制。结果表明:在CMP过程中,纳米二氧化硅磨料与晶圆表面发生了主要基于磨粒表面羟基官能团与加工材料表面之间强相互作用的固相反应。提出了磨粒粒径影响固相反应强度的机制。纳米二氧化硅磨料在蓝宝石CMP中对材料的去除是机械磨损和化学反应共同作用的结果,磨料的粒径是影响两者动态平衡的重要因素。建议采用混合粒径纳米二氧化硅磨料来抛光蓝宝石。

The chemical mechanical polishing(CMP)of sapphire wafers was conducted by using nano-SiO_(2) abrasives with different sizes.The effect of abrasive particle size on the surface performance and removal mechanism of sapphire wafer was studied by combining the experiment and simulative calculation of quantum chemical parameters.The results showed that a solid-phase reaction occurs between nano-SiO_(2) abrasive and wafer surface during CMP,which is mainly based on the strong interaction between the hydroxyl functional groups of the abrasive and the material surface.The mechanism of the effect of abrasive particle size on the strength of the solid-phase reaction was proposed.The removal of sapphire during its CMP results from not only the mechanical abrasion effect of nano-SiO_(2) abrasive on sapphire wafer,but also the chemical reaction between them.The abrasive particle size is an important factor affecting the dynamic balance of the said two roles.It is suggested to polish sapphire wafers using a mixture of nano-silica abrasives with different sizes.