CuCl_2-HCl酸性蚀刻液的ORP测量及其应用

通过测量CuCl2–CuCl–NaCl–HCl溶液的氧化还原电位(ORP),研究了酸性蚀刻液在蚀刻过程与电化学再生过程中ORP与溶液组成和温度的关系。结果表明,酸性蚀刻液的ORP随Cu+离子质量浓度的增加而降低,且在Cu2+离子质量浓度较高或总Cu质量浓度变化不大时与Cu+离子质量浓度的对数成正比。酸性蚀刻液中的溶解氧、Cu2+离子、Cl?离子和H+离子的浓度以及温度对ORP的测量有一定影响,但最大误差不超过0.9%。溶液组成一定时,ORP与测量温度成正比。ORP的测量可以指示酸性蚀刻液的蚀刻速率及其电化学再生过程。     

流体微通道浸泡蚀刻技术实验

微细加工技术是伴随着微制造的出现而产生的一类新型现代化制造技术,它实现了微小尺度范围内的机械加工和装配。化学蚀刻技术是微细加工技术主要的加工方法之一,包括浸泡、鼓泡、喷淋等方法,其中浸泡式蚀刻方法相对来说设备简单、操作方便、节约成本。本文采用单因素浸泡式方法对不锈钢板蚀刻进行了实验研究,研究了蚀刻时间、蚀刻液组分浓度及温度等因素对化学蚀刻质量的影响。结果表明,蚀刻液中FeCl₃浓度、H₃PO₄浓度、温度等对蚀刻速度、蚀刻均匀性、侧蚀及粗糙度有较大的影响。研究结果对流体微细通道的制造提供了初步工艺参数。     

铜表面化学蚀刻的研究

应用电化学反应原理和配位场理论,对以硫代硫酸钠和碳酸氢铵组成的蚀刻溶液的铜表面化学蚀刻原理进行了分析,认为:铜被硫代硫酸钠氧化为铜离子,铜离子与碳酸氢铵提供的氨分子迅速形成稳定的铜氨络离子。研究了各组分浓度、温度对蚀刻速率的影响作用,并进行了蚀刻溶液对钢设备的腐蚀性能研究。结果表明:随着溶液中硫代硫酸钠和碳酸氢铵浓度的增加,蚀刻速率增大,而碳酸氢铵的浓度受硫代硫酸钠浓度的限制,蚀刻溶液对钢设备没有腐蚀作用。     

印刷线路板动态蚀刻研究

为了优选酸性氯化铜蚀刻工艺条件,提高工作效率,采用喷射法动态试验,研究了影响印刷线路板铜箔蚀刻速率的因素.结果表明,当氯化铜质量浓度为150～250 g/L,盐酸浓度为1.6～3.0 mol/L,氟化钾浓度为1.4～1.6 mol/L,操作温度50 ℃左右,试样运动速率2.14 m/s时,蚀刻效果最佳,最高蚀刻速率接近60 μm/min.适当加大喷淋量有利于提高蚀刻速率.     

印刷线路板含铜废蚀刻液的回用处理(一)

本文分两部分刊出。第一部分介绍了印刷线路板的生产工艺,以及各种蚀刻液的特点。概述了影响酸性氯化铜蚀刻液蚀刻速率的因素及其槽液维护,比较了酸性与碱性氯化铜蚀刻液的性能及操作条件。     

铱-钽氧化物涂层阳极氧化再生酸性蚀刻液

采用Ir-Ta氧化物涂层阳极(DSA)和直流电解法研究了酸性蚀刻液的阳极氧化再生回用过程.酸性蚀刻液在Ir-Ta氧化物涂层阳极的氧化再生过程中发生浓差极化,电极反应速率为Cu+离子扩散传质所控制,极限电流密度与Cu+离子浓度和温度成正比,采用小于或等于极限电流密度的电流密度进行阳极氧化时不析出氯气.酸性蚀刻液阳极氧化再生的电流密度小,槽电压低,电解能耗少,电流效率可达到100%.阳极氧化再生后酸性蚀刻液的蚀刻能力与双氧水再生的相近,完全可以替代双氧水再生.     

铱-钽氧化物涂层阳极氧化再生酸性蚀刻液

采用Ir–Ta氧化物涂层阳极(DSA)和直流电解法研究了酸性蚀刻液的阳极氧化再生回用过程。酸性蚀刻液在Ir–Ta氧化物涂层阳极的氧化再生过程中发生浓差极化,电极反应速率为Cu+离子扩散传质所控制,极限电流密度与Cu+离子浓度和温度成正比,采用小于或等于极限电流密度的电流密度进行阳极氧化时不析出氯气。酸性蚀刻液阳极氧化再生的电流密度小,槽电压低,电解能耗少,电流效率可达到100%。阳极氧化再生后酸性蚀刻液的蚀刻能力与双氧水再生的相近,完全可以替代双氧水再生。     

三氯化铁蚀刻液的蚀刻能力研究

研究了三氯化铁蚀刻液对铁镍合金的蚀刻能力,通过对比实验,得出三氯化铁蚀刻液的最佳刻蚀温度为40℃,40℃时,20 mL蚀刻液的最大蚀刻速度为0.021 mg·min-1·mm-2；达到有效蚀刻量46.39 g/L时,蚀刻速度为0.009 4 mg·min-1·mm-2；达到最大蚀刻量58.79 g/L时,蚀刻速度为0.002 46mg·min-1·mm-2.     

氨碱性蚀刻液中铜溶解过程的化学动力学

氨碱性溶液是印制电路板工业中采用最为广泛的蚀刻溶液,但是关于溶液中铜溶解过程的动力学研究还比较缺乏。研究利用模拟实验的方法,定量地研究了铜溶解反应的化学动力学性质。当速度梯度G值大于7 570 s~(-1)时,铜溶解速率不受混合强度影响的传质速率限制;在反应前120 s内,平均单位面积铜溶解质量与反应时间呈线性关系,反应的速率常数约为0.137 3 mg/(cm~2·s);溶液Cu~(2+)浓度低于0.8 mol/L时,铜溶解速率随Cu~(2+)浓度增大而线性增大,此区间反应符合一级反应动力学;Cu~(2+)浓度约为1.0 mol/L时溶解速率最大;温度对反应速率的影响非常显著,升高温度反应速率增加较快,50℃时溶解速率可达21.106μm·L/(min·mol);溶解反应的Arrhenius活化能Ea约为23.7 k J,频率因子A约为1.43×10~5。     

采用稀盐酸和硝酸水解玉米芯产木糖及其优化

采用稀HCl和HNO₃在酸质量分数为1.0%、2.5%和4.0%,反应时间10、30、50、90和120 min,温度90和150 ℃条件下,对玉米芯水解产木糖进行研究。通过动力学模型数据预测木糖浓度,并采用响应曲面优化各个温度下的水解条件。优化得到的最适宜水解条件为温度150 ℃,预处理时间10 min,酸质量分数为1.0%;对应HNO.₃.得到的木糖浓度为56.77 g/L,产率96.31%;HCl木糖浓度为45.38 g/L,产率76.99%。动力学结果成功预测了反应条件下的木糖浓度。通过对比得出HNO.₃.对玉米芯的水解效果要优于HCl。     

Photoelectrochemical (PEC) etching of Ga2O3

In recent years, interest in the use of gallium oxide (Ga₂O₃) in semiconductor devices has increased due to its wide bandgap that permits device operation at high temperatures and high voltages. As the size of these devices decrease, it becomes more important to be able to produce features on the micro and nanoscale. Traditional etching (both wet and dry) have several limitations which either are unable to produce nano-features at the required scale or degrade device quality. Consequently, photoelectrochemical etching of Ga₂O₃ is of interest to researchers for its potential to produce features on the order of magnitude required while also causing minimal device degradation. Photoelectrochemical etching introduces a number of parameters that can be adjusted to control the etching process. In this work, we demonstrated photoelectrochemical etching of Ga₂O₃ by showing the effect of changing electrolyte concentration, anodic voltage, and etching time on the etching process. This etching method could be useful for a variety of applications which require complex patterning of Ga₂O₃ with high degrees of control compared to simple wet or dry etching processes.     

SELECTIVE REMOVAL OF HIGH-K GATE DIELECTRICS

Continuous downscaling of integrated circuits brought an end to the era of SiO₂. In gate dielectrics, it is being replaced by materials with high dielectric constant, so-called high-k dielectrics. One of the challenges in the integration of the high-k material is removal of those materials selectively over the substrate. This work is one of the first attempts to review current state of the art of the high-k removal. Two main approaches are discussed: dry (plasma) removal and wet removal. First, the fundamentals and limitations of both approaches are presented, then an overview of the existing experimental data is given. It is concluded that the best results could be obtained by combining the dry and wet approaches.     

Anisotropic copper etching with monoethanolamine-complexed cupric ion solutions

Monoethanolamine (MEA)-complexed cupric ion solution was used as a non-ammoniacal solution for copper etching on printed circuit boards (PCB). The copper dissolution behaviour of this MEA-complexed cupric solution containing 1 M CuCl₂ and 3.3 to 10 M MEA was studied by the potentiodynamic method at various temperatures (25–55 °C) and pH values (10–6.5). The effects of these factors on dissolution rate and etching factor of the copper patterns of PCBs were discussed. It was found that the highest corrosion current density (i _corr) was obtained with MEA concentration at about 5 M. Activation energies (E _a) of MEA-complexed cupric solutions were measured and the heat of adsorption (H _ads), which accounts for the chemisorption of the MEA ligands on the copper surface was calculated. H _ads was found to increase with solution containing excess MEA ([MEA] > 5 M), indicating the inhibition behaviour of MEA. Hence with lower pH, i _corr increased because the concentration of MEA ligands decreased due to acid reaction. The etching factor of copper patterns of PCBs with 75 m/75 m, line/space (L/S), were also tested by spray etching method. A high etching factor can be achieved for etchants containing high MEA concentration, which means MEA affects the etching factor since the inhibitive property of MEA reduces the undercut. Although the etching rate of MEA-complexed cupric etchant is still much lower than the ammoniacal etchant, the etching factor of the forward etchant (>3) is better than the latter (<2).     

Effect of HF and NaOH etching on the composition and structure of SiOC ceramics

Porous SiOC ceramics were prepared with tetraethoxysilane (TEOS) and vinyltriethoxysilane (VTES) as sol?gel precursors, and followed by etching with HF and NaOH solution. The microstructure evolution and chemical etching as a function of pyrolysis temperature were investigated. The amorphous carbon increases as rising the temperature from 800 ^oC to 1200 ^oC, and the graphitic carbon increases with further etching by HF and NaOH. However, the effect of pyrolysis temperature on the structure of C is more significant. The hydroxylation reaction and phase separation of SiOC ceramics results in the increase of SiO₄ unit, which reacts with HF and NaOH to form micro- and mesopores. The existence of mesopore after HF etching provides more specific surface area and pore volume. However, NaOH etching produces more micropores, and the contribution of micropores to specific surface area and pore volume is higher than that of mesopores. Although HF and NaOH etching increase the specific surface area of SiOC ceramics, the etching effect of NaOH is superior to that of HF etching, and the carbon-enriched SiOC ceramics are obtained after NaOH etching.     

The mechanism of galvanic/metal-assisted etching of silicon

Metal-assisted etching is initiated by hole injection from an oxidant catalyzed by a metal nanoparticle or film on a Si surface. It is shown that the electronic structure of the metal/Si interface, i.e., band bending, is not conducive to diffusion of the injected hole away from the metal in the case of Ag or away from the metal/Si interface in the cases of Au, Pd, and Pt. Since holes do not diffuse away from the metals, the electric field resulting from charging of the metal after hole injection must instead be the cause of metal-assisted etching.     

Modelling the capacitance of d.c. etched aluminium electrolytic capacitor foil

A model for the capacitance of anode foil used in aluminium electrolytic capacitors is compared with experimental data for commercial foils from two different manufacturers. These foils are obtained by anodic electrochemical etching to produce a porous tunnel etched structure, followed by formation of a layer of dielectric aluminium oxide in the pores. Data for the density and size of tunnels is obtained by sectioning the foil parallel to its surface with an ultramicrotome to several depths. In this paper the internal structure is modelled as a spatially random collection of hollow dielectric cylinders. Comparison of the measured capacitance with that calculated from the dimensional data and the model are in good agreement. The model predicts optimum values for tunnel size and density as a function of oxide thickness.     

FeCl3蚀刻液的再生研究

通过测定腐蚀液的氧化还原电位的变化,研究了FeCl3腐蚀液的失效规律,并以还原铁粉为置换剂,去除含镍的FeCl3腐蚀液中的镍组分.系统研究了铁镍比、反应温度、反应时间、溶液pH值等因素对FeCl3腐蚀废液再生恢复效果的影响.结果表明,随着腐蚀过程的进行,氧化还原电位在开始的10 min内迅速下降190 mV;当腐蚀液中所溶Fe-Ni合金的质量浓度达到65 g/L时,基本失去腐蚀能力;而加入高表面活性的铁粉,在n(Fe)/n(Ni)=3、提高反应温度、反应时间约为60min、pH≈4的条件下,腐蚀液的氧化还原电位恢复到新鲜腐蚀液的95%以上,达到了FeCl3腐蚀液再生利用的要求.     

Alkali preparation and ions detection of Ti3C2 quantum dots

In this paper, a simple lye etching method is used to directly prepare Ti₃C₂ quantum dot (QDs) without fluorine-containing groups at low lye concentration. The as-prepared Ti₃C₂ QDs have a stability fluorescent property in whole pH range of 1–14 and different fluorescence response to different types of heavy metal ions. Due to the unique and irreversible fluorescence quenching ability for Cr³⁺, Ti₃C₂ QDs can be used to detect Cr³⁺ with a low detection limit of 30 mM. Along with the high fluorescent selectivity and stability in pH = 1–14, Ti₃C₂ QDs is a great application prospect as Cr³⁺ ion detection probes in sewage disposal.     

线路板碱性蚀刻废液回收处理研究

本文简要介绍了线路板碱性蚀刻废液循环再生技术,分析了其原理和效率。     

Optimization of etching parameters of a fluorinated polyimide using the RIBE technique

A parametric study of etching a new type of fluorinated polyimide (6FDA-ODA) has been carried out. This kind of material was especially elaborated for plasma etching (reactive ion etching, RIE); its behaviour was tested with the reactive ion beam etching (RIBE) technique which uses an (O⁺) reactive ion beam and allows independent control of the ion energy and current density of the beam. Etch rates were measured as a function of energy (E), current density (J) and incident angle (θ) of the beam with the sample normal. These rates were shown to present a maximum value (1000Åmin^-1) for an energy flux of about 3Wcm^-2 (E=6keV and J=0·5mAcm^-2) and decreased when θ increased. These results were then compared with etching rates obtained with chemically inert ions (Ar⁺): in this case, etching rates were five times lower than those measured with O⁺ ions. © 1998 Society of Chemical Industry