Electrochemical materials and processes in Si integrated circuit technology

Various technical issues related to feature scaling and recent electrochemical technologies advances for on-chip copper interconnects at Intel are reviewed. Effects of additives on electroplating, as well as performance of novel Cu direct plating on ruthenium liner are discussed. An electroless cobalt capping layer of Cu lines, which led to increased electromigration resistance, has been characterized. The potential application of carbon nanotubes as future interconnects materials, their properties and controlled placement by using dielectrophoresis are also reviewed.     

电解法去除PAM生产废水中氨氮的研究

分别研究了铁板、铝板、钛板、镀钌钛板、镀二氧化铅钛板作为电极时PAM生产废水中氨氮的去除效果.结果表明,采用镀钌钛板电极比采用镀二氧化铅钛板电极具有更高的氨氮去除率;极板间距为0.5 cm时的氨氮去除率略优于极板间距为1 cm时的氨氮去除率;当放电时间超过6 min时,氨氮去除率随时间的变化曲线趋于平缓;采用镀钌钛板电...     

膦酸镀铜新工艺的研究

由于氰化预镀铜工艺存在镀液剧毒、污染环境等问题,作为替代工艺,本文研究了HEDP(羟基乙叉二膦酸)直接镀铜新工艺,分析了镀液主要成分的作用及操作条件的影响,并与氰化物预镀工艺进行了比较。实验表明在此工艺条件下,镀液的分散能力与覆盖能力与氰化镀铜相当,电流效率比氰化镀铜高得多,可达90%以上,镀层结合力良好,基本无脆性,具有代替氰化物镀铜的良好前景。     

电气铝排无氰镀铜的性能研究

比较了电气用铝排(6101铝合金)无氰镀铜与氰化镀铜后的镀层外观、金相、孔隙率、接触电阻、可焊接性、极化曲线的差异,并在不同工艺及厚度的镀铜层上电镀5μm厚度的锡层,通过Tafel极化曲线、中性盐雾试验、高温高湿试验对其耐腐蚀性能进行评估.结果表明,无氰镀铜光泽度好,接触电阻低,但整平能力、深度能力、可焊接性和孔隙率不...     

有机中间体对电镀酸性硬铜硬度的影响

近年来,铁基圆筒电镀厚铜替代铜辊的电镀硬铜加工量随凹印制版产量的增加而急剧增长.但与普通酸性光亮镀铜相比,国内外能供选择的商品酸性电镀硬铜光亮剂为数较少,涉及镀层硬度影响因素的研究更少.本文主要对目前国内外常见的酸性镀铜中间体、单体光亮剂对硬度的影响进行了测试研究.     

Modification of copper by redox reaction: location of Ru on Cu-Ru bimetallic catalysts

Raney copper catalysts were modified by addition of ruthenium by means of an oxido-re-duction reaction between copper surface and ruthenium chloride in aqueous solution. Energy dispersive spectroscopy fitted to a STEM unit allowed to conclude that the active sites for the selective conversion of glucitol into 1,4–3,6-dianhydroglucitol are composed of ruthenium and chlorine located on low coordinated copper atoms.     

新型配位剂对化学镀铜工艺的影响

在以柠檬酸钠为配位剂、次磷酸钠为还原剂的化学镀铜工艺的基础上,加入一种新型配位剂,研究了新的化学镀铜工艺。比较了新化学镀铜工艺与传统的化学镀铜、化学镀镍工艺的不同。结果表明:新型化学镀铜工艺沉积速率快、镀液稳定性好、成本低,是很好的代镍工艺。     

碱性无氰镀铜工艺研究

通过对碱性无氰镀铜工艺、镀液及镀层性能研究,得到该工艺可作为钢铁基体的预镀铜,也可直接用于镀厚铜,镀层与基体的结合力良好,结晶细致,光亮。镀液成分简单,易操作,稳定,具有良好的分散能力,电流效率也优于氰化镀铜。     

钢铁基体上无氰碱性电镀铜用配位剂的研究

分别以乙二醇、乙二胺四乙酸(EDTA)、氨水、缩二脲、柠檬酸盐及膦酸盐为配位剂进行无氰碱性镀铜试验。对不同镀液体系的稳定性、电导率及所得镀层的外观、结合力等进行了测试。结果表明,乙二醇、EDTA、柠檬酸盐及膦酸盐都可以作为碱性镀铜的配位剂,而氨水和缩二脲体系由于存在明显的置换反应,因此不适用于无氰镀铜体系。复合膦酸盐镀铜体系的综合性能最好,有望替代传统的氰化物镀铜体系。     

碳纤维布化学镀铜工艺的研究

采用以甲醛为还原剂的化学镀铜液,用硝酸银作活化剂,在碳纤维布表面沉积出连续、均匀、有光泽的化学镀铜层。研究了不同前处理工艺对碳纤维布化学镀铜的影响。采用扫描电子显微镜表征了化学镀铜层的表面形貌,并用数字电压表测试了碳纤维布化学镀铜前后的导电性。     

电镀铜技术在电子材料中的应用

电镀铜层具有良好的导电、导热、延展性等优点,因此,电镀铜技术被广泛应用于电子材料制造领域。本文概括了几种常用电镀铜体系的特点,重点介绍了在电子制造中应用较广的酸性硫酸盐电镀铜镀液的组成和各成分作用。简述了电镀铜在铜箔粗化、印制电路制作、电子封装、超大规模集成电路(ULSI)铜互连领域的应用,并对近年来电子工业中应用的几种先进电镀铜技术,包括脉冲电镀铜技术、水平直接电镀铜技术、超声波电镀铜技术、激光电镀铜技术等进行了评述。     

配位剂对Al_2O_3陶瓷表面化学镀铜的影响

研究了EDTA,NaKC4H4O6以及两者复配后,对Al2O3陶瓷表面化学镀铜沉积速率、微观形貌、表面粗糙度和镀液稳定性的影响。结果表明:EDTA为配位剂时,化学镀铜镀速为3.86μm/h,镀层表面粗糙度为0.39μm,镀层铜微粒形成团聚,均匀性较差;NaKC4H4O6为配位剂时,镀速为4.55μm/h,表面粗糙度为0.46μm,镀层表面有直径达2~5μm的杂质微粒;EDTA和NaKC4H4O6复配使用时,镀速为4.17μm/h,表面粗糙度为0.35μm,铜镀层微观组织致密,铜微粒大小分布均匀,排列紧密,表面平滑、洁净。     

ABS塑料化学镀铜工艺

介绍了ABS塑料表面化学镀铜的工艺流程,讨论了粗化温度和时间、敏化和活化时间、硫酸铜质量浓度、甲醛体积浓度、酒石酸钾钠质量浓度、镀液温度和镀液pH对镀层质量以及化学镀铜沉积速率的影响。确定了最佳工艺条件为15~20g/L硫酸铜、15mL/L甲醛、14g/L酒石酸钾钠,镀液温度为323K,镀液的pH为11~12。扫描电镜表明,所得镀层均匀、光亮,结合力好。     

氮化铝陶瓷表面化学镀铜溶液组成的优化

采用正交试验方法研究了镀液组成对氮化铝(AIN)陶瓷表面化学镀铜镀速和表面粗糙度的影响.经过直观分析和方差分析,评价了各组分对化学镀影响的显著程度,优化了镀液组成.试验结果表明,CuSO_4·5H_2O和Na_2EDTA对镀速有显著影响;KNaC_4H_4O_6、CuSO_4·5H_2O和Na2EDTA对镀后表面粗糙度有显著影响;AIN陶瓷表面化学镀铜液的最优工艺参数为:CuSO_4·5H_2O 24 g/L,Na_2EDTA 30 g/L,KNaC_4H_4O_6 20 g/L和HCHO 15 mol/L.在最优工艺条件下,镀速为7.350 μm/h,镀后表面粗糙度为1.03 μm,所得镀层表面平整,铜晶粒大小均匀.     

Plating fog generation in the forming of printed circuits by the additive method

Plating fog is often observed when metallizing a latent pattern by electroless copper plating. Metallic elements in the nuclei of plating fog particles are analysed using electron probe microanalysis (EPMA). Silver and iron are invariably found in the particles. The iron is driven into the board during the liquid honing process and reduces silver ions in the photosensitive material to silver metal which causes plating fog. Plating fog also arises from reduced copper particles or generated hydrogen gas bubbles when they are trapped on the unpatterned region. Mechanical stirring accompanied by substrate oscillation is an effective method of avoiding plating fog.     

Carbon monoxide hydrogenation over silica-supported ruthenium-copper bimetallic catalysts

The catalytic properties of a series of ruthenium-copper catalysts supported on silica were studied. It was found that while the amount of CO adsorbed at 273 K measured with the pulse-flow method is higher on the catalysts with a small concentration of copper than on the pure ruthenium catalyst, the yield of Ru⁺ secondary ions on fast atom bombardment of the catalyst surface with argon is suppressed by the addition of copper. The activity for CO disproportionate as well as CO hydrogenation were drastically reduced by the presence of copper. It is estimated that an ensemble of between 4 to 6 adjacent ruthenium atoms is required for CO disproportionation and one of between 9 to 13 adjacent ruthenium atoms is required for CO hydrogenation. Comparisons between the properties of the supported catalysts and those of single-crystal model catalysts were made.     

The co-deposition of copper and zinc inclusion in electrodeposition of silver from silver cyanide bath

The co-deposition behavior of a trace of copper and zinc as an impurity in cyanide baths for silver plating was studied by means of a radioactive tracer. The authors selected ⁶⁴CuCN and ⁶⁵Zn(CN)₂ as a labelled compound and added it to the cyanide baths for silver plating.Each amount of copper and zinc co-deposited with silver increased with increasing copper and zinc concentration in silver plating baths and temperature. It was found that the co-deposition of copper and zinc depended on cathode potentials and was not diffusion-determining. The co-deposition of copper abruptly increased in the high current density range. In the potential range Cu co-deposition is observed with Cu reversible potential through limiting current of silver deposition, and evolution of hydrogen. At low current density, Cu and Zn co-deposition are saturated at about 6400 Å thickness of electrodeposited silver and occluded in the electrodeposits is not smooth and coarse structure is observed on it.     

Simulation of electrochemical nucleation in the presence of additives under galvanostatic and pulsed plating conditions

Galvanostatic nucleation of copper onto pretreated ruthenium is investigated using experimental methods and numerical simulations in the presence of two different suppressor molecules; polyethylene glycol (PEG) and ethylene glycol-propylene glycol-ethylene glycol block copolymer (EPE). The model parameters have been largely determined from electrochemical characterization. Results suggest that a fast adsorption rate of the suppressor results in higher nucleus densities. Simulation results provide insight why EPE is more effective than PEG at increasing nucleus density. In addition, the simulations are used to predict the impact of pulse plating paramaters, showing that both the properties of the additive and the waveform need to be considered to optimize nucleus density enhancement.     

酸性镀铜光亮剂的开发

在酸性镀铜电解液中要获得良好的镀铜层,关键在于选择性能优良的酸性镀铜光亮剂,而酸性镀铜光亮剂的开发关键在于中间体的选择和复配.介绍了酸性镀铜光亮剂的组成、常用的中间体及其作用以及复配方法.详细说明了酸性光亮镀铜的配方和操作条件;通过对比试验,对酸性镀铜光亮剂进行综合评价.     

化学镀铜原理、应用及研究展望

化学镀铜技术主要用作印制线路板孔金属化和塑料电镀,其镀层具有良好的延展性、导热性和导电性,介绍了化学镀铜的应用范围与发展,强调了化学镀铜预处理的必要性及要注意的几个方面：应用易清洗的油脂作防锈剂,低碳钢件用阳极电解除油,酸洗除油与碱性除油互补等。介绍了化学镀铜的一些常用体系及其主要组分。讨论了添加剂的影响,对非金属表面化学镀铜的研究进展进行了报道,提出了化学镀铜今后的研究重点。