二氧化硅磨料粒径分布对蓝宝石化学机械抛光的影响

针对蓝宝石晶圆化学机械抛光(CMP)高去除速率和高抛光质量的要求,对比了分别采用单一粒径、连续粒径和混合粒径的SiO2磨料对蓝宝石晶圆的抛光效果.结果表明,将粒径为120 nm的40％(质量分数)硅溶胶与粒径为30 nm的20％(质量分数)硅溶胶按体积比8:2混合作为磨料对蓝宝石晶圆进行CMP时,去除速率最高,抛光后蓝宝石晶圆的表面粗糙度(Ra)低至0.158 nm,无明显的划痕、划伤等缺陷.     

化学机械抛光技术研究进展

通过回顾化学机械抛光技术的发展历史,概述了化学机械抛光作用机制与实际应用情况,着重阐述了几种重要抛光浆料(如CeO2、SiO2、Al2O3抛光浆料)的优缺点、抛光机理及其国内外新近制备方法,进一步展望了化学机械抛光技术的发展前景与新型抛光浆料的开发方向.     

硅衬底化学机械抛光液的循环使用性能

采用8%(质量分数,下同)有机碱A和3%有机碱B作为抛光液的复配p H调节剂对硅衬底进行化学机械抛光。研究了2种有机碱单独使用或复配使用时对抛光速率和抛光表面质量的影响。结果表明,当2种有机碱复配时,硅衬底的平均抛光速率达到1.04μm/min,同时可获得低表面粗糙度(Ra=0.621 nm)和无划痕的抛光表面。该抛光液在循环使用过程中表现出良好的稳定性,循环使用10次后抛光表面质量基本无变化,但抛光速率略降,主要与抛光液pH降低、黏度增大以及硅溶胶颗粒团聚有关。     

碳化硅化学机械抛光中金刚石磨粒与二氧化硅磨粒作用的微观模拟分析

采用反应力场(ReaxFF)分子动力学方法模拟分别以金刚石磨粒和二氧化硅磨粒对碳化硅进行化学机械抛光时的表面微观行为,探讨了这2种硬度不同的磨粒对碳化硅表面原子的去除机制.结果表明,二氧化硅磨粒在抛光过程中相比金刚石磨粒更容易发生化学反应,主要通过持续与碳化硅表面原子成键和断键来实现原子的去除.金刚石磨粒能够使碳化硅表...     

蓝宝石化学机械抛光液的研究进展

简介了蓝宝石化学机械抛光(CMP)的基本原理,从磨料、pH调节剂、表面活性剂、配位剂和其他添加剂方面概述了近年来蓝宝石CMP体系的研究进展,展望了蓝宝石CMP体系未来的研究方向。     

Selection of an oxidant for copper chemical mechanical polishing: Copper-iodate system

Diagnostic criteria were developed to elucidate the reduction mechanism of an oxidant on a copper (Cu) surface at the corrosion potential. The corrosion potential of Cu tu was measured for various pH and iodate (IO₃^–) concentrations using the rotating disk electrode technique. According to the measured corrosion potentials, IO₃^– was an effective CMP oxidant only below pH Application of the diagnostic criteria on the Cu – IO₃^– system showed that the reduction of IO₃^– on Cu was under the mixed kinetic and diffusion control at the corrosion potentia l below pH 3. Above pH 3, however, the anodic process dominated over the cathodic process.     

Study on the interaction between SiO2 and ZrO2 in the chemical mechanical polishing of zirconia ceramic with colloidal silica

Colloidal silica is usually used for the chemical mechanical polishing of zirconia ceramic wafer in industry, but the process is often optimized only through experience without a precise understanding of the polishing mechanism. There are still many theoretical and technical issues, especially the material removal mechanism and the effect of polishing on the phase transformation, have not been studied in depth. In this study, the effect of the abrasive concentration, polishing pressure and slurry pH on the material removal rate was analyzed. It is found that the removal rate tends to be stable when the concentration exceeds 30 wt%; the influence of pressure on the polishing rate conforms to the Preston formula. When the pH of the slurry is 6, the removal rate is the highest, but polishing under acidic conditions will leave corrosion pits due to the dissolution of the stabilizer. Through X-ray photoelectron spectroscopy analysis of the residue on the wafer surface, it was found that Si-O-Zr bonds were formed, but it was uncertain whether the residue was zirconium silicate. Through X-ray diffraction analysis, it is found that polishing will not affect the crystal structure of zirconia. The Zr-O-Si bond formed by tribochemical action on the ceramic surface prevents the deep migration of surface hydroxyl groups. At the same time, kinetic factors will cause internal hydroxyl groups to transfer to the surface for recovery oxygen vacancies, thereby stabilizing the tetragonal phase.     

电化学测试技术在集成电路制程化学机械抛光中的应用现状

简述了包括开路电位法、极化曲线法、恒电位法、电化学阻抗谱在内的常规电化学测试技术的原理.总结了近几年内这几种电化学测试技术在化学机械抛光领域研究中的应用现状,展望了未来的发展方向.     

硅片化学机械抛光表面材料去除非均匀性实验

化学机械抛光技术已成为超大规模集成电路制造中实现硅片全局平面化的实用技术和核心技术。CMP的最大问题之一是硅片材料去除的非均匀性,它是集成电路对硅片表面平坦化需求的一个重要指标。文章提出了硅片表面材料去除非均匀性计算公式,在CP-4实验用抛光机上进行了硅片化学机械抛光实验,并用美国ADE公司生产的WaferCheck-7200型非接触式电容厚度测量设备对单晶硅片的厚度进行高精度检测,经过计算,得出了不同抛光速度下硅片表面材料去除非均匀性的数据,为理解硅片CMP材料去除非均匀性形成机理,进一步揭示硅片CMP材料去除机理提供了理论依据。     

光催化氧化对GaN材料腐蚀电化学及化学机械抛光的影响

考察了氮化镓(GaN)晶片在不同质量分数和pH的溴酸钾(KBrO3)溶液中的腐蚀电化学行为.结果显示,GaN在溴酸钾质量分数为1％时腐蚀电位最低.在此基础上使用光催化氧化法能够显著降低腐蚀电位,使GaN材料的腐蚀速率进一步提高.CMP实验结果显示:紫外光(UV)的加入使GaN在1％KBrO3溶液(pH=4)中的抛光速率...     

Effect of silica fume, metakaolin, and low-calcium fly ash on chemical resistance of concrete

Effects of aggressive chemical environments were evaluated on the mortars prepared with ordinary portland cement (OPC) and silica fume (SF)/metakaolin (MK)/low-calcium fly ash at various replacement levels. The natural adverse chemical environmental conditions were simulated using sulfuric acid, hydrochloric acid, nitric acid, acetic acid, phosphoric acid, and a mixture of sodium and magnesium sulfates. Chemical resistance information was used in conjunction with compressive strength measurements to propose realistic OPC/mineral admixture proportions.     

Preparations of silica slurry for wafer polishing via controlled growth of commercial silica seeds

Silica slurry in aqueous medium for wafer polishing was prepared by sol-gel reaction of silicon alkoxide utilizing commercial silica particles as seeds that were grown stepwise through intermittent additions of tetraethylorthosilicate (TEOS) as a silica precursor. Before the growth reaction, the commercial silica particles were pre-treated in the vibratory mill partially filled with zirconia ball and the sonicator to ensure good dispersion. The alcohol left after growth reaction was removed by vacuum distillation and repeated washings with distilled water followed by centrifugations. Then, the alcohol-free silica particles were redispersed in water. The dispersion stability of the silica slurries was examined by measuring surface charge of silica particles and rheological properties. Finally, wafer-polishing performance of the prepared silica slurries was considered by measuring the polishing (or removal) rate, and RMS (root mean square) roughness of the polished wafer surface. For the polishing, MEA (monoethanolamine) and TMAH (tetramethylammonium hydroxide) were used as polishing accelerators. The polishing result showed that the removal rate was nearly independent of the concentrations of MEA and TMAH in the range of 0.3-0.5 wt% and 100-500 ppm, respectively. One of the most interesting features is that hydrothermal treatment of the prepared silica slurries in autoclave increased the removal rate as high as ten times. Although the removal rate was increased by the increased size of the abrasive particle, surface roughness of the polished wafer surface was deteriorated.     

Roles and mechanistic analysis of adenine as a green inhibitor in chemical mechanical polishing

Journal of Applied Electrochemistry - In the process of multilayer copper wiring CMP (chemical mechanical polishing), electrochemical corrosion will occur due to the contact between slurries and...     

浅谈不锈钢化学抛光添加剂的选择

介绍了不锈钢化学抛光添加剂的种类、作用及其用量,测定并比较了不锈钢试片在含有两种添加剂的抛光液中进行抛光后的外观和表面粗糙度。结果表明,添加剂对抛光效果的影响较大。     

Preferential adsorption of polycarboxylate superplasticizers on cement and silica fume in ultra-high performance concrete (UHPC)

UHPC is fluidized particularly well when a blend of MPEG- and APEG-type PCEs is applied. Here, the mechanism for this behavior was investigated. Testing individual cement and micro silica pastes revealed that the MPEG-PCE disperses cement better than silica whereas the APEG-PCE fluidizes silica particularly well. This behavior is explained by preferential adsorption of APEG-PCE on silica while MPEG-PCEs exhibit a more balanced affinity to both cement and silica. Adsorption data obtained from individual cement and micro silica pastes were compared with those found for the fully formulated UHPC containing a cement/silica blend. In the UHPC formulation, both PCEs still exhibit preferential and selective adsorption similar as was observed for individual cement and silica pastes. Preferential adsorption of PCEs is explained by their different stereochemistry whereby the carboxylate groups have to match with the steric position of calcium ions/atoms situated at the surfaces of cement hydrates or silica.     

Review on copper chemical-mechanical polishing (CMP) and post-CMP cleaning in ultra large system integrated (ULSI)—An electrochemical perspective

The current review describes electrochemical evaluation and study of copper chemical-mechanical polishing (CMP) slurries and post-CMP cleaning solutions. Electrochemical and surface analyses of commercial and new developed CMP slurries over the last decade are discussed. It is stated that the main CMP requirement needed from slurries, to provide copper passivity, is not being complied in all commercial slurries, since copper is being actively dissolved in all of them. Two novel systems based on alkaline weak acid salts (K-sorbate and K-carbonate) are being reviewed, as well. Once considering post-CMP slurries it is shown that HNO₃ based solutions are highly effective in copper layers etching. Simultaneous etching of silicon oxide and copper layers can be efficiently conducted in diluted HF solutions. The composition of etching solution usually includes inhibitors, and surface active compounds. However, copper etching in aqueous solutions is usually accompanied with a deposition of corrosion products (Cu(1) compounds). Formation of such deposition is being determined electrochemically subsequent to an etching process (at OCP) in some of the recommended post-CMP cleaning solutions. Cautious consideration should be taken once choosing the most appropriate etching solution for Cu post-CMP cleaning.     

不锈钢拉伸工件化学抛光工艺

不锈钢拉伸工件采用常规的化学抛光工艺不能达到理想的效果。提出了一套较理想的不锈钢拉伸工件化学抛光工艺。介绍了该工艺的流程、规范，以及化学抛光原理及影响因素，