半导体硅片的电化学研究(英文)

采用电化学直流极化和交流阻抗技术 ,在有光照和黑暗条件下分别研究了半导体硅片在稀释氢氟酸溶液中的电化学特性 .两种电化学技术均对溶液中含有的微量铜 (1 0 - 9wt % -浓度水平 )非常敏感 ,但仅对溶液中的 1 0 - 6 wt % -浓度水平的非离子型表面活性剂敏感 .结果表明 ,有光照条件下在硅 /溶液界面上极易发生电化学反应 ,且该反应对硅表面性质起主导作用 .     

黄铜-16Mn钢在氯化钠溶液中腐蚀电化学的分布行为

使用扫描微电极技术研究了黄铜-16Mn钢电偶体系在不同浓度氯化钠溶液中表面电位和电流的分布情况. 研究发现, 表面电位和电流分布随溶液浓度和与连接点的距离而变化. 溶液浓度越大, 两者分布就越均匀; 与连接点距离越近, 电位极化就越大, 电流密度也越大. 腐蚀形貌观测也支持了电位和电流分布的结果. 实验结果表明, 在低浓度的溶液中, 电偶腐蚀会集中在连接点周围,造成严重的局部腐蚀. 随着溶液浓度增大, 腐蚀分布变得均匀.     

硅片表面多金属污染的交流阻抗表征

在接近氢氟酸实际应用浓度条件下, 利用交流阻抗技术研究了硅片表面金属微观污染行为, 在氢氟酸溶液中分别加入0.5和1 mg/g的铜、铁、镍、钙四种金属离子, 获得了硅片在单金属溶液中的特征交流阻抗谱, 并在此基础上研究了三种金属及四种金属共存时的特征交流阻抗谱, 通过等效电路的拟合估算了硅/氢氟酸界面电化学反应的动力学参数, 并结合扫描电镜形貌图探讨了不同类型的单金属和多金属对硅电化学行为的影响. 结果表明, 多金属微观污染是各种单金属协同作用的结果, 铜在硅片上发生电化学沉积, 直接导致硅片表面粗糙化. 铁对硅片表面的破坏严重, 同时影响铜的沉积. 镍的存在使硅片表面更容易氧化. 而钙通过在硅片表面形成氟化钙沉淀物可以钝化表面, 减缓铜在硅片表面的沉积.     

预处理对多孔硅形成过程的影响(英文)

本工作初步探讨了开路电位下对硅片进行预处理时多孔硅的形成过程 .电化学极化实验、扫描电镜和拉曼谱学的研究表明 ,预处理可以加速硅 /溶液界面上的化学或电化学反应 ,从而加快多孔硅的生长过程 ,最终导致光致发光的光谱红移 .多孔硅的厚度随预处理时间的增长而减小     

电极/溶液界面pH值的现场测量

一般认为阴极表面功能陶瓷电沉积层的形成是由于基底 /溶液界面化学环境变化造成的 [1,2 ] ,但目前还没有直接的实验数据加以证明 .原位测量电极 /溶液界面 p H的变化存在两方面的困难 :(1 )传统方法是采用玻璃 p H计 ,由于其体积较大、强度脆弱等原因 ,使其在测量固 /液界面化学环境变化的应用方面受到一定限制 [3 ] ;(2 )将 p H微探针置于电极表面 ,将会影响功能陶瓷在电极表面的沉积 ,从而使测定的界面 p H值不能真实反映电沉积过程中固 /液界面化学环境的变化 .本文基于功能陶瓷电沉积过程不受影响的情况下现场直接测量电极 /溶液界面…     

铁铬合金摩擦破损微电偶的形成及作用

本文分析，研究了１Ｃｒ１８合金材料在０．２ｍｏｌ．Ｌ＾１Ｈ２ＳＯ４溶液中的摩擦腐２蚀过程中产生微电偶腐蚀的可能性及原因，并研究了微电偶对摩擦电化学行为的影响，研究结果表明：由于摩擦过程造成材料表面的电化学不均一性是产生微电偶作用的真正原因。未摩擦表面与摩擦表面的面积比显著地影响了摩擦电偶电位和摩擦电偶电流的大小。     

N型宏孔硅电化学腐蚀中表面活性剂对 Si/HF界面的影响

该论文研究了N型宏孔硅电化学腐蚀中表面活性剂对Si/HF界面的影响.分别用含有阳离子、阴离子、非离子表面活性剂和无表面活性剂的HF腐蚀液进行宏孔硅光电化学腐蚀实验,测试了电化学阻抗谱EIS和Mott-Schokkty曲线,分析了N型宏孔硅电化学反应过程中的电荷转移电阻和Si/HF界面处Si基体一侧的空间电荷层电容.结果...     

在Ca（NO3）2溶液中氧化铝／水界面上的三层模型的参数

本文报道了在Ca（NO3）2溶液中，氧化铝的水悬浮液的电位滴定数据，根据实测表面电荷密度与理论计算值的比较，认为在界面上生成了络合物（S-O）2Ca。电位滴定是在Ca（NO3）2浓度0．0033、0．033、0．33mol／L下进行的，并由此测定了在氧化铝／水界面上三层模型的参数。利用所得参数，计算了表面电荷、电势及各表面组分的浓度随Ca（NO3）2浓度和pH的变化，并将此结果与在NaNO3溶液中的进行比较。结果表明，在Ca（NO3）2溶液中比在NaNO3溶液中，PZNPC向低pH值移动，从7．4降到6．8。     

物理化学学报

正1.热力学,动力学和结构化学(化学平衡与热力学参数、量热学、非平衡态热力学与耗散结构、统计热力学、宏观动力学、分子动态学、超快动力学、激发态、溶液化学、复杂流体、溶液结构、大气化学、动态结构、分子结构、体相结构、簇、谱学)2.理论与计算化学(量子化学、统计力学、模拟方法与应用、计算化学、化学信息学)3.电化学和新能源(电极过程动力学、界面电化学、电催化、谱学电化学、电化学表面科学、材料电化学、光电化学、纳米电化学、电化学能量转换与储存、腐蚀电化学)     

Zn含量对Mg-Zn合金在模拟体液中腐蚀行为的影响

采用析氢实验、扫描电子显微镜和X射线衍射等研究经过固溶处理的纯Mg和镁锌合金模拟体液中的腐蚀行为。结果表明:几种镁锌合金的腐蚀速率远低于纯镁,镁锌合金的腐蚀速率随着Zn含量降低而降低。固溶处理降低了晶界数量和位错密度,减少了晶间腐蚀和点蚀的发生,随着第二相含量增加造成相界面增加,暴露在表面的相界面成为电偶腐蚀发生的位置,因此本研究中镁锌合金的腐蚀以电偶腐蚀以主。显微组织观察发现纯镁的表面腐蚀产物比较疏松,而Zn的加入使镁锌合金在模拟体液中的腐蚀产物变得平整致密,但随着Zn含量的提高,第二相的体积分数上升,腐蚀产物的裂纹增大,造成腐蚀速度上升。     

Electrochemical characterization of copper chemical mechanical polishing in l-glutamic acid–hydrogen peroxide-based slurries

The effect of l-glutamic acid as complexing agent in the presence of hydrogen peroxide as oxidizer in copper chemical mechanical polishing (CMP) slurry is investigated. In the CMP process, the work surface is moved against a pad, with slurry flowing between the surface and the pad. The polish rate was found to be stable over a wide range of hydrogen peroxide concentration. High concentration of either l-glutamic acid or hydrogen peroxide leads to a reduction in polish rate, but a high concentration of both chemicals does not reduce the polish rate. In the absence of hydrogen peroxide, the Cu polish rate was 0 for all the l-glutamic acid concentrations investigated. However, potentiodynamic polarization curves do not show any sign of passivation when l-glutamic acid was present in the solution. In situ open circuit potential measurements show that copper redox reactions as well as hydrogen peroxide redox reactions contribute in determining the electrochemical behavior. We propose that l-glutamic acid inhibits the copper dissolution by adsorption onto the metallic copper, but enhances copper dissolution by complexing copper ions. The results show that it is possible to conduct controllable copper CMP in mildly acidic slurries with hydrogen peroxide as oxidizer and l-glutamic acid as complexing agent.     

铜在甲胺介质铁氰化钾化学-机械抛光液中的电化学行为

二甲氧基苯胺;铜在甲胺介质铁氰化钾化学-机械抛光液中的电化学行为     

The use of monodispersed colloids in the polishing of copper and tantalum

The properties of abrasive particles play a significant role in chemical mechanical polishing (CMP) of metal and dielectric films in semiconductor device manufacturing. This study investigates the effects of the particle size, shape, and hardness of abrasives on the polishing of copper and tantalum films in the presence of different slurry chemistries. Well-defined dispersions of uniform particles, including spherical silica of varying diameters, hematite of different shapes, and hematite cores coated with silica of different thicknesses, were prepared and used to polish blanket films of Cu and Ta. It was shown that the total surface area of the solids in the slurry controlled the rate of material removal by pure silica for both Cu and Ta, while the surface quality of the polished films was better when higher silica content was used. The shape or the aspect ratio of hematite particles had a minor effect on the removal rate. In contrast, when hematite particles coated with silica were employed in the polishing of Cu and Ta, the polish rate decreased with increasing thickness of the shell.     

Role of poly(diallyldimethylammonium chloride) in selective polishing of polysilicon over silicon dioxide and silicon nitride films

A cationic polymer, poly(diallyldimethylammonium chloride), or PDADMAC (MW ≈ 200,000), at a concentration of 250 ppm was used to enhance polysilicon removal rates (RRs) to ～600 nm/min while simultaneously suppressing both silicon dioxide and silicon nitride RRs to <1 nm/min, both in the absence or in the presence of ceria or silica abrasives during chemical mechanical polishing (CMP). These results suggest that aqueous abrasive-free solutions of PDADMAC are very attractive candidates for several front-end-of-line (FEOL) CMP processes. Possible mechanisms for the enhancement of poly-Si RR and the suppression of oxide and nitride RRs are proposed on the basis of the RRs, contact angle data on poly-Si films, zeta potentials of polishing pads, polysilicon films, silicon nitride particles, and silica and ceria abrasives, thermogravimetric analysis, and UV-vis spectroscopy data.     

AFM and FTIR studies of organic cation adsorption on carbon steel coupled with stainless steel

The electrochemical behavior of the anode of the galvanic couple and the adsorption behavior of the cationic inhibitor on it have been investigated by using electrochemical methods, atomic force microscopy (AFM) and infrared spectroscopy (FTIR) technology. A galvanic electrode was prepared by coupling N80 carbon steel (CS) and S31803 stainless steel. All experiments were performed in NaCl solution in the presence or absence of an inhibitor. The results show that, in aqueous NaCl solution, CS carries negative excess charge, for the couple, positive charge is carried on the CS side (anode). The adsorption behavior of the cationic inhibitor on CS is significantly affected by the excess charge carried on it. Owing to the charge interaction between electrodes and the cationic inhibitor, the inhibitor has a greater tendency to adsorb on the single CS and less tendency to adsorb on the CS of the couple. Because of this, the adsorption film on the anode (CS side) of the couple is thin and defective. The failure of inhibiting galvanic corrosion attributes to the defective protective layer formed on the anodic area. Copyright © 2006 John Wiley & Sons, Ltd.     

Fe-W非晶镀层的磷化及在NaCl溶液中的腐蚀行为

ＦｅＷ非晶态合金镀层在酸性溶液中具有高耐蚀性能,但在中性和碱性溶液,特别是在氯化钠溶液中耐蚀性能差［１］,如在３０℃、１ｍｏｌ／ＬＨＣｌ溶液中,ＦｅＷ非晶镀层的腐蚀速率约为不锈钢ＳＵＳ３０４的１／１５;在６０℃、０５ｍｏｌ／ＬＨ２ＳＯ４溶液中约...     

Electrochemistry of marmatite-carbon paste electrode in the presence of bacterial strains

The electrochemical behaviors of a marmatite-carbon paste electrode with the chemical leaching of Fe3+ ions, or the microbial leaching using Acidithiobacillus ferrooxidans, were compared. The cyclic voltammograms of the electrode in the presence and absence of bacterial strains showed that the leaching process of marmatite was carried out by the different reactions occurring in the interface of the marmatite electrode-leach liquid. The polarization currents of the electrode under the differently applied potentials suggested that the microbial leaching of marmatite could be accelerated by the applied potential. The SEM observations indicated that the corrosion pits formed in the electrode surface were similar to the attached bacterial cells in shape and size, other than that by the chemical leaching of Fe3+ ions. The contact leaching of the attached cells on the mineral substrate played an important role on the dissolution of marmatite in addition to the chemical leaching of Fe3+ ions.     

镀锌扁钢电力接地材料在NaCl介质中的腐蚀特性

应用极化曲线、电化学阻抗谱和中性盐雾腐蚀试验法,研究电力接地材料镀锌扁钢在5%NaCl溶液中的腐蚀行为,扫描电子显微镜（SEM）、X射线衍射仪（XRD）观察与表征镀锌扁钢样品腐蚀的表面形貌及其产物性质.结果表明,在20～60℃温度范围内,镀锌扁钢腐蚀电流随温度升高而增大,60℃时腐蚀速率达到0.8408mA.cm-2（...     

Influence of surface preparation and microstructure on the passivity and corrosion behaviour of duplex stainless steels

The influence of various surface preparation methods (mechanical polishing, electropolishing and etching) on the passivity and the corrosion behaviour of a duplex stainless steel (UNS S32202) was studied using Auger spectroscopy and the electrochemical microcell technique. From surface analyses, the thickness and chemical compositions (ratios Cr/Fe and O^2?/OH^?, distribution of chloride and nitrogen) were determined. The corrosion behaviour of samples was investigated from local polarization curves. The presence of oxidation peaks and stable pitting was discussed considering the specimen microstructure and the properties of the passive film.     

Corrosion depth profiles of nitrided titanium alloy in acidified sulphate solution

Thick (400 µm) glow-discharge nitrided layers, TiN+Ti₂N + αTi(N) type, have been produced on the Ti-1Al-1Mn titanium alloy. Using a progressive thinning method, the polarization characteristics at different depths of nitrided layers have been measured. From the plots of obtained potentiodynamic polarization curves the depth profiles of characteristic anodic and cathodic currents (at potentials corresponding to (a) hydride formation, (b) hydrogen evolution, (c) primary passivation, (d) oxygen evolution and (e) secondary passivation) as well as polarization resistance have been determined in 0.5 M Na₂SO₄ solution acidified to pH = 2. The anomalously high slope of the polarization curves in the cathodic region has been ascribed to the formation of titanium hydride. It has been shown that outer nitrided layers (up to 25 µm) exhibit excellent acid corrosion resistance owing to strong inhibition of the anodic process by TiN phase. Corrosion resistance of deeper situated layers gradually decreases and at depths of 250–370 µm the corrosion process is accelerated by presence of TiO₂ precipitations. Nitrided layers, unlike the alloy core, allow oxygen evolution on the oxy-nitrided surface at potential of +1.6 V and at more positive potentials gradual transformation of the surfacial film into TiO₂ takes place. Secondary passivation on nitrided titanium is less efficient than that in the absence of Ti-N species.