介孔氧化硅微球的合成及其在化学机械抛光中的应用

Synthesis of Mesoporous Silica Microspheres and Their Application in Chemical Mechanical Polishing

利用阳离子表面活性剂（十六烷基三甲基溴化铵）胶束与硅源（正硅酸乙酯）的协同组装过程,通过改进的St？ber法制备具有放射状孔道的介孔氧化硅（Mesoporous silica,Sm）微球。结果表明：所得Sm微球粒径在260～480 nm范围内,样品的BET比表面积为1300～1500 m2/g,其内部孔道孔径集中在2～3 nm。利用原子力显微镜比较了Sm磨料与常规实体氧化硅（Solid silica,Ss）磨料对热氧化硅片的抛光特征。经Sm磨料抛光后,衬底表面粗糙度均方根值（RMS）为0.240 nm,表面微观轮廓起伏在±0.70 nm范围内,抛光材料去除率（MRR）可达93 nm/min。与Ss磨料相比,Sm磨料有利于降低抛光衬底粗糙度,提高材料去除率,并有效避免出现微划痕等表层机械损伤。

The mesoporous silica （Sm） microspheres with radial channels were prepared via a developed Stober method and the self-assembly of anionic surfactant （cetyltrimethylammonium bromide） micelles with silica precursors （tetraethoxysilane）. The results indicate that the particle sizes of the Sm microspheres range from ca. 260 to 480 nm, and the Brunauer-Emmett-Teller specific surface areas are 1 300-1 500 m2/g and the mesochannel sizes are in a range of 2-3 nm. The chemical mechanical polishing characteristics of Sm and solid silica （Ss） particle abrasives for oxidized silicon substrates were investigated by atomic force microscopy. The root-mean-square surface roughness （RMS） of the substrate after polishing with Sm abrasives is 0.240 nm, and the topographical variation is 4-0.70 nm and the material removal rate （MRR） is 93 nm/min. Compared to the Ss particles, the as-synthesized Sm particles can be used to further decrease the surface roughness, increase the material removal rate and eliminate the surface mechanical damage.