Thermodynamics of copper matte converting: Part IV.A priori predictions of the behavior of Au,Ag, Pb,Zn, Ni,Se, Te,Bi, Sb,and As in the Noranda Process reactor

The general formulae are derived which allow calculation of the weight of each molten phase (copper, matte, slag) in the Noranda Process reactor as a function of matte grade and suspension indices. These expressions and the volatilization constants are then inserted in the steady-state volatilization equation (derived in the Part III) to calculate the overall distribution of minor elements and their concentrations in all the reactor products(i.e., copper, matte, slag, and offgas) in the Noranda Process. The overall distribution of ten minor elements can be predicted for any set of controllable process parameters such as feed composition, temperature, degree of oxygen enrichment, slag composition (or magnetite activity), and matte grade. The computer predictions are in good agreement with the commercially observed values with the exception of selenium. Formerly Associate Professor, Department of Metallurgical Engineering, University of Utah, Salt Lake City, UT     

Volatilization of bismuth in copper matte converting — computer simulation

A computer model has been developed to simulate the behavior of bismuth in copper matte converting at 1100 to 1300 ‡C. The rate equation is integrated numerically by dividing a continuous process of matte converting into a great number of microsteps, in each of which the volatilization of Bi-bearing gases is thermodynamically calculated by assuming a steady state. The bubbles of offgas consisting of SO₂ and N₂ are assumed to be saturated with the vapors of BiS, Bi, BiO, and Bi₂. However, the partial pressures of BiO and Bi₂ are found to remain negligible at all stages of converting. BiS is the most volatile species over the slag-making stage with low grade mattes, but its volatility decreases markedly, becoming negligibly low over white metal. When the copper content of the initial matte is known together with the weight of matte, converting temperature and blowing rate of tuyere air, the present computer model can predict the Bi contents in all the phases involved (gas, slag, matte, copper) at any given time. The predictions by the present computer model are compared with the known commercial data from various smelters around the world. The agreements between the computer predictions and the commercial data are excellent in all cases, so that the present computer model can be used to monitor and optimize the bismuth elimination in the actual industrial operations of copper matte converting. Formerly Associate Professor, Department of Metallurgical Engineering, University of Utah, Salt Lake City, UT 84112     

Interpulse kinetics in copper and copper halide lasers

The various rate processes that govern the interpulse relaxation in metal vapor and metal halide vapor lasers are considered. Computer calculations indicate that the rapid metastable levels relaxation observed in copper and copper halide laser experiments requires the existence of a relatively small resonance in the cross section for metastable excitation or deexcitation near threshold. The accurate calculation of interpulse relaxation requires knowledge of rate constants presently not well known; this is especially so for metal halide lasers.     

铜激光光脉冲的时间特性

测量了铜激光两种波长510.6nm和578.2nm光脉冲的抽运时间与氖压和充电电压间的关系。波长578.2nm的光脉冲的抽运时间在不同氖压下随电压的增加而缩短。波长510.6nm光脉冲的抽运时间与电压的关系对氖压较为敏感。     

New precursors for CVD copper metallization

A novel CVD copper process is described using two new copper CVD precursors, KI3 and KI5, for the fabrication of IC or TSV (Through Silicon Via) copper interconnects. The highly conformal CVD copper can provide seed layers for subsequent copper electroplating or can be used to directly fabricate the interconnect in one step. These new precursors are thermally stable yet chemically reactive under CVD conditions, growing copper films of exceptionally high purity at high growth rates. Their thermal stability can allow for elevated evaporation temperatures to generate the high precursor vapor pressures needed for deep penetration into high aspect ratio TSV vias. Using formic acid vapor as a reducing gas with KI5, copper films of >99.99 atomic % purity were grown at 250 °C on titanium nitride at a growth rate of > 1500 Å/min. Using tantalum nitride coated TSV type wafers, ∼ 1700 Å of highly conformal copper was grown at 225 °C into 32 μm × 5 μm trenches with good adhesion. With ruthenium barriers we were able to grow copper at 125 °C at a rate of 20 Å/min to give a continuous ∼ 300 Å copper film. In this respect, rapid low temperature CVD copper growth offers an alternative to the long cycle times associated with copper ALD which can contribute to copper agglomeration occurring.     

注入锁定铜蒸气激光器的时空、能量以及偏振特性

采用P分量的偏振光注入到平行平面腔的铜蒸气激光器中,结果表明,与未加注入光时的振荡器比较,注入锁定铜蒸气激光器的输出功率提高了43％,P分量的偏振度从0.30提高到0.78,脉宽由36ns加宽到48ns,输出光的发散角显著改善,由7.8mrad降到1.1mrad,与注入光束基本相同。     

铜蒸气激光器

以纯铜或铜的卤化物蒸气作激光工作物质,利用高重复频率谐振布鲁林放电线路激励,得到5106(?)和5782(?)激光输出.当充电电容量为1.5毫微法,充电电压6000伏,脉冲重复频率16千赫时,激光平均输出功率为1.2瓦.     

Texture and microstructure of thin copper films

Microstructure is an important factor influencing the reliability of thin film interconnects. The microstructure of copper films is of particular interest because of its use in numerous electronic applications. Pole figure x-ray diffraction and transmission electron microcopy were conducted on copper films deposited by several techniques: sputtering, partially ionized beam deposition, chemical vapor deposition, evaporation, and electroplating. Quantitative texture data are determined from fiber texture plots. A typical copper film consists of three texture components: (111), (200), and random. (220) and (511) texture components are possible under some deposition conditions. Compared to aluminum films, the fraction of the random texture component and the distribution of the (hkl) components in copper films are relatively large. Bimodal grain size distributions are observed in some films.     

封闭式高重复脉冲铜蒸气激光

一、引言 铜蒸气激光具有高增益、高功率和高效率等特点,受到普遍的注意。最初的铜蒸气激光是用纯铜在氧化铝管中加热到1500℃而产生铜蒸气作为工作物质的。人们为了降低工作温度,找到了卤化铜作为工作物质,使激光的运转温度在400℃至600℃,而激光的功率仍保持不变。卤化铜激光最初是采用双脉冲工作方式,第一个放电脉冲产生卤化铜的分解,第二个放电脉冲则使铜原子在电子碰撞下激发到激光上能级。1974年,双     

High pulse rate, mode-locked copper vapor laser

The operating characteristics of a compact copper vapor laser which displays self-mode-locked operation and is capable of operating at pulse rates to 150 kHz are described.     

铜蒸气激光器的热设计

本文系统阐述了铜蒸气激光器的设计过程.在大量实验资料的基础上,给出了激光器放电管尺寸、输入功率密度的选择原则,通过分析放电管内气体温度分布、激光管径向热导损耗,建立了一套确定保温层厚度的方法.分析了光束"黑心"的原因,进而提出了解决途径.以上的设计思想在我们新近研制5W器件上得到验证.     

Reliability challenges for copper interconnects

In the past few years, copper has been widely used as interconnect metallization for advanced ultralarge-scale integration (ULSI) circuits. Due to the unique chemical properties of copper compared to its predecessor, aluminum, different integration processes must be used for circuit fabrication, that is, the damascene versus reactive ion etch (RIE) process. This difference in integration processes introduces a series of reliability concerns for copper interconnects. After a brief comparison of copper and aluminum interconnects, this article discusses the impact of the differences in the material properties and integration process on reliability. Details are provided on two advanced metallization reliability failure mechanisms: electromigration and stress migration. For copper interconnects, the interface between the cap and the copper metal serves as the fast diffusion path. To improve copper interconnect reliability, development efforts have focused on suppressing copper or copper vacancy diffusion along the interface. Two copper interfaces, the copper/cap interface and the copper/liner (or diffusion barrier) interface, are critical for copper reliability. For commonly used liners, such as Ta/TaN, the copper/liner interface is relatively easy to control compared to the copper/cap interface. For dual-damascene copper lines, a copper via is used to connect the lower level to the upper level. Unlike the robust tungsten stud used in aluminum interconnects, the copper via has been identified as a weak link in dual-damascene copper connections; the majority of early reliability failures can be attributed to the copper vias. The three most critical process factors and elements affecting copper interconnect reliability are copper vias and interfaces and the liner coverage. Using a low-k dielectric with a copper interconnect introduces several new challenges to reliability, including dielectric breakdown, temperature cycle, and stability within packages. Extensive knowledge is urgently needed to understand these issues.     

Effect of temperature on copper indium selenization

The reaction kinetics of copper indium diselenide formation is studied by measuring species composition as a function of time at 250°C and 325°C in a tubular chemical vapor deposition reactor. This extends our previous modeling and experimental study at 400°C. The initial copper–indium alloy is analyzed at the reaction temperatures using high-temperature X-ray diffraction measurements. This modifies the understanding of the chemistry of the copper indium growth kinetics and a new set of model equations is presented. The specific reaction rate constants and activation energies for the chemical reactions are obtained, enabling one to calculate the holding time for the reaction. © 1997 John Wiley & Sons, Ltd.     

Vapor pressures of the adducts formed during AlGaN organometallic vapor-phase epitaxy

We have measured the vapor pressure of the adducts of trimethylgallium (TMGa) and trimethylaluminum (TMAl) with ammonia near room temperature. The vapor pressures of the mixtures of the adducts were also measured and found to obey Raoult’s law. Both the gallium and aluminum adduct have a relatively low vapor pressure (410 mtorr and 74 mtorr, respectively, at 19°C), which places limits on the design and operation of AlGaN organometallic vapor-phase epitaxy (OMVPE) reactors. Adduct condensation may also be the explanation for numerous observations of powders and crystals inside OMVPE reactors.     

铜蒸气激光链中激光脉冲的抖动分析

运用概率论方法导出了铜蒸气激光链中激光脉冲抖动量的表达式,结果表明:当铜蒸气激光器并联时,两台激光器输出光脉冲之间的抖动量的平方等于每台激光器输出光脉冲相对于电触发脉冲抖动量的平方和;当多台铜蒸气激光器串联放大时,第m台激光器输出光脉冲相对于振荡器输出光脉冲的抖动量随m的增加而增加,但总是小于每台激光器放电脉冲抖动量的2~(1/2)百倍。实验结果与理论计算基本相符。     

Afterglow ground-state copper density behavior in kineticallyenhanced copper vapor lasers

The interferometric “Hook” method has been used to measure the copper ground-state density during the interpulse period for a 38 mm bore diameter copper vapor laser (CVL) operated in kinetically enhanced (KE) mode (Ne-HCl-H₂ gas mixture) and in conventional mode (pure neon and Ne-H₂ gas mixtures). It was found that the rate of regrowth of the axial copper density during the afterglow of the KE-CVL is 3-4 times faster, and the axial prepulse ground-state copper density is 2-3 times higher, than that observed for pure Ne or Ne-HI buffer gases. We conclude that the primary action of the HCl+H₂ additives is to increase the interpulse plasma relaxation rate and to increase the threshold copper density beyond which thermal runaway occurs. These effects are primarily responsible for the elevated pulse rates and increased pulse energies giving improved power scaling characteristics of KE-CVLs     

铜蒸气激光器的改进及稳定

通过改变放电管中铜粒的位置、放电管外层保温材料的性质和厚度以及对放电产生的电磁辐射进行屏蔽等措施,进一步提高了25W铜蒸气激光器的可靠性和稳定性。     

A discharge heated copper vapor laser

A simple, reliable copper vapor laser is described with vapor produced by discharge heating. Average output power of 1.3 W has resulted at 6.8 kHz and a specific energy of 39 μJ/cm³. Copper vapor density as high as3 times 10^{16}cm^-3was achieved.     

Fabrication and characterization of sub-quarter-micron MOSFETs witha copper gate electrode

Sub-0.25-μm P- and N-MOSFETs with a chemical vapor deposited copper gate electrode were fabricated using a novel nitride cast method wherein a silicon nitride gate is used as a stand-in gate which is then replaced by Cu with a PVD TiN barrier metal after source/drain formation. The maximum processing temperature after copper deposition is 400°C. Excellent device performance was obtained on both P- and N-MOSFET. No signs of copper diffusion were observed after device fabrication and after bias-temperature stress tests at 200°C     

铜蒸气激光照射对血管平滑肌细胞凋亡的诱导作用及对其增殖的影响

目的：研究510.6nm铜蒸气激光照射对体外培养的血管平滑肌细胞（VSMC）凋亡的诱导作用，以及对增殖细胞核抗原（PCNA）表达的影响，探讨铜蒸气激光照射在经皮冠状动脉成形术（PTCA）后再狭窄（RS）的防治作用。方法：贴块法培养兔VSMC，510.6nm铜蒸气激光照射后透射电镜观察凋亡细胞形态学改变，TUNEL法计数凋亡细胞，免疫组化染色法计数照光对PCNA阳性表达率的影响。结果：激光照射后，VSMC凋亡率较未照光组增加12.8倍，而PCNA表达阳性率降低27．9％倍；电镜下观察细胞呈典型的凋亡形态学改变。结论：铜蒸气激光照射可以诱导VSMC凋亡，而且抑制其增殖，在RS的防治中具有一定的作用。