石英晶片剪切增稠抛光优化实验

剪切增稠抛光(STP)是利用非牛顿流体抛光液在抛光过程中产生的剪切增稠效应实现工件表面高效、低损伤的抛光.本文以材料去除率和表面粗糙度作为评价指标;采用田口法对石英晶片剪切增稠抛光过程中的4个关键影响参数:抛光液转速、工件倾斜角度、磨粒粒度、磨粒质量分数进行优化实验分析,得到最优抛光参数组合以及各主要工艺参数对抛光效果的影响程度;通过实验验证了优化结果的可靠性.对于材料去除率,工件倾斜角度的影响最明显,抛光液转速次之,再次是磨粒质量分数,磨粒粒度影响最小;对于表面粗糙度,抛光液转速的影响最明显,工件倾斜角度次之,再次是磨粒质量分数,磨粒粒度影响最小.通过信噪比平均响应分析,材料去除率优化参数组合为:Al_2O_32 500#、磨粒质量分数18%、抛光液转速80 r/min、工件倾斜角度15°,石英晶片材料去除率最高达到12.25μm/h;石英晶片最佳表面粗糙度参数组合为:Al_2O_35 000#、磨粒质量分数18%、抛光液转速80 r/min、工件倾斜角度15°,抛光1 h后石英晶片表面粗糙度R_a由300.08 nm降低至4.26 nm.     

精细雾化抛光氮化硅陶瓷的抛光液配制参数优化

采用超声精细雾化施液抛光对氮化硅陶瓷基体进行抛光,研究了不同的pH值、磨料浓度以及氧化剂含量对氮化硅陶瓷基体抛光的材料去除率的影响,优化了pH值、磨料浓度及氧化剂含量,并与传统的化学机械抛光进行了对比。结果表明:当二氧化硅磨粒质量分数为5wt%,氧化剂含量为1wt%,pH值为8时,材料去除率MRR为108.24nm/min且表面粗糙度Ra为3.39nm。在相同的抛光参数下,传统化学机械抛光的材料去除率MRR为125nm/min,表面粗糙度Ra为2.13nm;精细雾化抛光的材料去除率及表面粗糙度与传统抛光接近,但精细雾化抛光所用抛光液用量仅为传统抛光所用抛光液用量的1/9。     

内核尺寸对核/壳结构PS/SiO_2复合磨料抛光特性的影响

核/壳结构有机/无机复合微球作为一种新型抛光介质,在实现高效无损伤抛光方面具有重要的应用价值。以无皂乳液聚合法制备的聚苯乙烯(PS)为内核,通过溶胶-凝胶法合成了一系列具有不同内核尺寸的PS/SiO2复合微球。利用FT-IR、FESEM和TEM等手段对样品进行表征,并借助AFM考察了复合磨料内核尺寸对SiO2介质层抛光质量的影响规律。结果表明,所制备单分散PS微球尺寸在200~600 nm,复合微球的壳层由SiO2纳米颗粒(5~10nm)所组成,壳厚在10~15 nm。材料去除率(MRR)随复合磨料内核尺寸的减小而降低,而抛光后晶片表面粗糙度(RMS)的变化则不明显。当复合磨料内核尺寸为210 nm时,抛光后RMS和MRR分别为0.217 nm和126.2 nm/min。提出将核壳结构有机/无机复合磨料理解成一种表面布满无机纳米颗粒的微型"抛光垫",尝试用有效磨料数量以及壳层中单个SiO2颗粒的压入深度对CMP实验结果进行解释,并进一步讨论了有机内核在抛光过程中的作用。     

固结磨料抛光LBO晶体非水基抛光液优化

三硼酸锂(LBO)晶体是优良的非线性光学晶体材料,抛光后晶体表面水份残留导致晶体潮解,影响器件的使用性能。采用非水基抛光液固结磨料抛光LBO晶体,降低水含量,研究非水基抛光液中去离子水、乳酸、双氧水等含量对材料去除率和表面粗糙度的影响,并综合优化得到高材料去除率和优表面质量的抛光液组分。研究表明,抛光液中去离子水浓度16%、乳酸22%、双氧水5%为最优抛光液组分,采用优化的抛光液固结磨料抛光LBO晶体的材料去除率达到392nm/min,表面粗糙度为0.62nm,实现了LBO晶体表面的高效高质量抛光,同时避免了抛光过程中水的大量使用。     

精细雾化抛光TFT-LCD玻璃基板的抛光液研制

以混合磨料氧化铈和氧化硅、pH调节剂羟乙基乙二胺、表面活性剂聚乙烯吡咯烷酮为原料配制抛光液,通过对TFT-LCD玻璃基板进行超声波精细雾化化学机械抛光的正交试验研究,优化了抛光液的成分,并对传统抛光和雾化抛光进行了对比。结果表明:当氧化铈和氧化硅的质量分数分别为4%和10%、pH值为11、表面活性剂的质量分数为1.5%时,材料去除率MRR为215nm/min,表面粗糙度Ra为1.6nm。在相同的试验条件下,传统抛光的去除率和表面粗糙度分别为304nm/min和1.5nm;虽然雾化抛光去除率略低于传统抛光,但抛光液用量仅为传统的1/8。     

同质异构_SSiO_2/_MSiO_2核/壳复合磨粒的合成

以正硅酸乙酯为硅源、以氨水为催化剂、十六烷基三甲基溴化铵为结构导向模板剂,在单分散实心氧化硅(Solid-SiO2,SSiO2)内核表面包覆介孔氧化硅(Mesoporous-SiO2,MSiO2)外壳,合成了同质异构氧化硅(SSiO2/MSiO2)核/壳复合磨粒。用小角XRD、FESEM、HRTEM、FTIR、TGA和氮气吸附-脱附等手段对样品的结构进行了表征。结果表明,具有放射状介孔孔道的MSiO2均匀连续包覆在SSiO2内核(210-230nm)外表面,形成了厚度为70-80nm的外壳。壳层中的介孔孔道(孔径约2-3nm)基本垂直于内核表面,且复合磨粒样品具有较大的比表面积(558.2m2/g)。用AFM形貌分析和轮廓分析评价了所制备的复合磨粒对SiO2薄膜的抛光特性。与常规实心SiO2磨粒相比,SSiO2/MSiO2复合磨粒明显改善了抛光表面质量并提高了材料去除率。这可能归因于MSiO2壳层通过机械和/或化学方面的作用对磨粒与衬底之间真实界面接触环境的优化。     

抛光液组分对硬盘盘基片超光滑表面抛光的影响

在硬盘盘基片的最终抛光中,研究SiO2溶胶颗粒、氧化剂、络合剂和润滑剂对盘基片Ni—P材料抛光性能的变化规律,获得较高的材料去除速率（MRR）和原子级光滑表面,以满足下一代硬盘盘基片制造的更高要求．结果表明,采用平均粒径25nm的SiO2溶胶颗粒,易减少微划痕等缺陷;以过氧化氢为氧化剂,可大幅提高MRR;加入有机酸络合剂后,MRR显著增大,其中含有水杨酸的抛光液MRR最大,并讨论不同络舍剂对盘基片去除的影响机理;丙三醇润滑剂的引入,使抛光中摩擦系数减小,盘基片的表面粗糙度得到明显降低．采用原子力显微镜（AFM）、光学显微镜和ChapmanMP2000＋表面形貌仪来考察盘基片抛光后的表面质量,基于抛光液各组分的影响作用,最终获得表面粗糙度尺。为0．08nm的盘基片表面,且MRR达到0．132μm／min．     

Sm掺杂核-壳结构介孔SiO2@CeO2复合颗粒的制备和抛光性能

在低模量介孔SiO2(Mesoporous silica, mSiO2)微球表面负载Sm掺杂CeO2纳米粒子,制备了具有均匀完整核-壳结构的非刚性mSiO2@Ce1-xSmxO2(x=0, 0.23)复合颗粒。借助XRD、 SEM、 HRTEM、 STEM-EDX Mapping、 Raman光谱和N2吸-脱附等技术对产物进行结构表征,利用AFM和三维光学轮廓仪评价Sm元素掺杂处理对mSiO2@Ce1-xSmxO2(x=0, 0.23)复合颗粒抛光效果的影响。讨论了Sm掺杂复合磨粒的高效无损超精密抛光机制。结果表明:掺杂处理可使mSiO2@Ce1-xSmxO2(x=0, 0.23)复合颗粒的抛光效率提高近36%,达到84 nm/min,同时获得具有原子量级精度的加工表面,抛光后SiO2薄膜的粗糙度平均值和均方根分别为0.14和0.17 nm。     

Fe3O4/SiO2/CMCH/CdTe荧光磁性微球的合成与表征

利用St ber法和交联法制备出具有荧光和磁性功能的Fe3O4/SiO2/CMCH/CdTe微球,并对其性能和应用效果进行了分析讨论.首先以正硅酸四乙酯为前躯体,Fe2＋和Fe3＋物质的量的比为1∶2,利用超临界干燥法制备出了Fe3O4/SiO2复合微球;并通过透射电镜对其进行观察,Fe3O4颗粒粒径为10 nm,SiO2层厚度为5 nm;其次羧甲基化的壳聚糖（CMCH）被嫁接在Fe3O4/SiO2表面上;然后利用水热法制备出CdTe荧光颗粒,通过壳聚糖与CdTe之间的静电吸引作用,CdTe被吸附在壳聚糖表面;最后利用戊二醛对壳聚糖的选择性交联作用制备出粒径在200 nm以内,饱和磁化强度为22.16 A.m2/kg,且具有良好荧光性能的Fe3O4/SiO2/CMCH/CdTe微球.荧光光谱分析表明最大发射波长从519 nm红移到528 nm,也证实了荧光颗粒CdTe成功吸附在Fe3O4/SiO2/CMCH表面.在动物实验中,该复合微球也显示出良好的荧光性、磁性及稳定性.     

乳酸体系抛光液中锇的化学机械抛光

本文研究了乳酸(HL)体系抛光液中金属锇的化学机械抛光(CMP)行为,采用电化学分析方法和X射线光电子能谱仪(XPS)分析氧化剂和腐蚀抑制剂的作用机理,利用原子力显微镜(AFM)观察抛光前后锇的表面形貌.结果表明,当抛光液仅含有H2O2时,金属锇表面腐蚀不明显;在一定浓度范围内H2O2浓度的增加可以提高金属锇表面的腐蚀速度,但是不利于金属锇表面钝化膜的形成.当抛光条件为:压力为6.895 kPa,转速为50 r/min,抛光液流量为50 mL/min,pH值为5.0;抛光液组成为:SiO2质量分数为1%,HL质量分数为1%,H2O2质量分数为3%时,得到最大去除速率为23.34 nm/min,表面粗糙度Ra为6.3 nm,而将缓蚀剂BTA加入到抛光液后,在同样的抛光条件下得到的锇表面粗糙度更低,表面粗糙度Ra达到2.1 nm.     

Preparation of porous Fe2O3/SiO2 nanocomposite abrasives and their chemical mechanical polishing behaviors on hard disk substrates

Abrasives play an important role in chemical mechanical polishing (CMP) processes. Compact solid silica particles, which have been widely used as abrasive in CMP slurries, may cause surface defects because of their high hardness. Porous silica abrasive exhibits better surface planarization and fewer scratches than traditional solid silica abrasive during the polishing of hard disk substrates. However, the improvement in material removal rate (MRR) was not significant. Therefore, porous Fe₂O₃/SiO₂ nanocomposite abrasives were prepared and their CMP performances on hard disk substrates were investigated. Experiment results indicate that the MRR of slurry containing porous Fe₂O₃/SiO₂ nanocomposite abrasives is obviously higher than that of slurry containing pure porous silica abrasive under the same testing conditions. MRR increases with the increase of the molar content of iron in porous Fe₂O₃/SiO₂ nanocomposite abrasives. Moreover, surfaces polished by slurries containing the porous Fe₂O₃/SiO₂ nanocomposite abrasives exhibit lower surface roughness, fewer scratches as well as lower topographical variations than that by pure porous silica abrasive.     

Preparation of porous alumina abrasives and their chemical mechanical polishing behavior

Porous alumina abrasives with different pore sizes were prepared using hydrothermal synthesis method by different hydrothermal temperatures. The pore structure, pore size and pore volume of the products were characterized by transmission electron microscopy and nitrogen adsorption desorption isotherm measurement. The chemical mechanical polishing (CMP) performances of porous alumina abrasives in hard disk substrate CMP were investigated. The results show that, the polished surface average roughness (Ra) decreases when the pore diameter of porous alumina abrasive increases. By comparison with solid alumina abrasive, the prepared porous alumina abrasives give lower Ra, and the porous alumina abrasive with 8.61 nm pore diameter has higher material removal rate under the same polishing conditions.     

Mechanism of high selectivity in ceria based shallow trench isolation chemical mechanical polishing slurries

dl-aspartic acid as a removal rate selectivity enhancer for shallow trench isolation chemical mechanical polishing slurries was investigated over a pH range. The effects of downward pressure, rotational speed of the turntable as well as the ceria abrasive loading were also examined. The selectivity is very sensitive to changes in the pressure but not to changes in the rotational speed. Select experiments were also conducted with other types of abrasives with and without the additive. A comparison of the pK_a values of the amino acid with the variation of the selectivity with pH indicates that the form of amino acid plays a vital role in determining the polishing behavior and the selectivity. Further, the results corroborate the hypothesis that chemically active sites on the abrasive may be blocked by certain forms of the amino acids, leading to changes in the selectivity.     

蓝宝石衬底化学机械抛光的机理研究

利用磨料为SiO2的碱性抛光液对蓝宝石衬底材料进行了化学机械抛光，并对蓝宝石衬底化学机械抛光（简称CMP）的机理进行了深入的研究，指出了蓝宝石CMP的主要的动力学过程，并详细分析了影响各动力学过程的诸要素。结果表明，蓝宝石衬底的CMP过程是一个复杂的多相反应过程，是化学作用与机械作用互相加强和促进的过程，影响它的各要素间既相互促进，又相互制约。     

Empirical approach to develop a multilayer icebonded abrasive polishing tool for ultrafine finishing of Ti-6Al-4V alloy

This paper covers the development of a multilayer icebonded abrasive polishing (IBAP) tool for multistage polishing of Ti-6Al-4V alloy specimens based on a systematic study that determined the number of layers, thickness of each layer, and the type, size and concentration of abrasives in each layer. Based on this study, a three-layered IBAP tool with the bottom layer consisting of soft aluminum oxide abrasives of 3?µm size with 5% concentration, the middle layer with moderately hard silicon carbide abrasives of 8?µm size with 10% concentration and the top layer with hard boron carbide abrasives of 15?µm size with 30% concentration was formulated for ultrafine finishing of Ti-6Al-4V alloy specimen in a single setup. The performance of the three-layered IBAP tool assessed in terms of finish and morphology over the work surface showed 81% improvement in surface finish, showing its effectiveness over a single-layered IBAP tool. Polishing studies have clearly demonstrated the generation of ultrafine surfaces, yielding a finish of 37?nm while the morphological studies on the polished surface have shown a nearly scratch-free surface on the Ti-6Al-4V alloy.     

Effect of slurry composition on the chemical mechanical polishing of thin diamond films

Nanocrystalline diamond (NCD) thin films grown by chemical vapour deposition have an intrinsic surface roughness, which hinders the development and performance of the films’ various applications. Traditional methods of diamond polishing are not effective on NCD thin films. Films either shatter due to the combination of wafer bow and high mechanical pressures or produce uneven surfaces, which has led to the adaptation of the chemical mechanical polishing (CMP) technique for NCD films. This process is poorly understood and in need of optimisation. To compare the effect of slurry composition and pH upon polishing rates, a series of NCD thin films have been polished for three hours using a Logitech Ltd. Tribo CMP System in conjunction with a polyester/polyurethane polishing cloth and six different slurries. The reduction in surface roughness was measured hourly using an atomic force microscope. The final surface chemistry was examined using X-ray photoelectron spectroscopy and a scanning electron microscope. It was found that of all the various properties of the slurries, including pH and composition, the particle size was the determining factor for the polishing rate. The smaller particles polishing at a greater rate than the larger ones.     

Structural regulation and polishing performance of dendritic mesoporous silica (D-mSiO2) supported with samarium-doped cerium oxide composites

Ceria (CeO₂) particles are prevalent polishing abrasive materials. Trivalent lanthanide ions are the popular category of dopants for enriched surface defects and thus improved physicochemical properties, since they are highly compatible with CeO₂ lattices. Herein, a series of dendritic-like mesoporous silica (D-mSiO₂)-supported samarium (Sm)-doped CeO₂ nanocrystals were synthesized via a facile chemical precipitation method. The relation of the structural characteristics and chemical mechanical polishing (CMP) performances were investigated to explore the effect of Sm-doping amounts on the D-mSiO₂/Sm_xCe_1?xO_2?δ (x = 0–1) composite abrasives. The involved low-modulus D-mSiO₂ cores aimed to eliminate surface scratch and damage, resulting from the optimized contact behavior between abrasives and surfaces. The trivalent cerium (Ce³⁺) and oxygen vacancy (V_O) at CeO₂ surfaces were expected to be reactive sites for the material removal process over SiO₂ films. The optimal oxide-CMP performances in terms of removal efficiency and surface quality were achieved by the 40% Sm-doped composite abrasives. It might be attributed to the high Ce³⁺ and V_O concentrations and the enhancement of tribochemical reactivity between CeO₂SiO₂ interfaces. Furthermore, the relationship between the surface chemistry, polishing performance as well as the actual role in oxide-CMP of the D-mSiO₂/Sm_xCe_1?xO_2?δ abrasives were also discussed.     

纳米CeO2颗粒的制备及其对硅晶片（100）和（111）的抛光性能

以硝酸铈和六亚甲基四胺为原料,在微波辐射条件下,使用乙醇/水反应体系,通过均相沉淀法制备了纳米CeO2颗粒,利用X射线衍射仪（XRD）、透射电子显微镜（TEM）、傅里叶转换红外光谱仪（FT-IR）和比表面积测定仪（BET-N2）等手段对样品的成分、物相结构、形貌、颗粒大小以及团聚情况进行了表征.将所制备的纳米CeO2颗粒作为磨料用于硅晶片（100）和（111）的化学机械抛光,用原子力显微镜（AFM）观察抛光表面的微观形貌,测量表面粗糙度,并对抛光表面划痕进行了分析.结果表明,微波辐射以及乙醇/水反应体系均有利于制备出粒径更小、分散性更好的纳米CeO2颗粒,而且微波辐射能够显著加快反应速度;经纳米CeO2磨料抛光的硅晶片（100）和（111）表面非常平整,在2μm×2μm范围内的粗糙度Ra值分别为0.275 nm和0.110 nm,获得了具有亚纳米量级粗糙度的抛光表面.