膜去溶进样高分辨ICP-MS测定半导体级硝酸中杂质元素

利用高分辨电感耦合等离子体质谱测定半导体级高纯硝酸中的痕量金属杂质,用膜去溶进样系统直接进样,用标准加入法进行上机检测,无需前处理,快速,避免了在样品前处理时的污染问题。高分辨电感耦合等离子体质谱可以消除多分子离子干扰,降低检出限,提高定量准确性。方法的检出限为0.69～23.73ng/L,加标回收率为88.2%～106.0%,方法简单,结果可靠,适用于高纯硝酸中痕量元素的快速测定。     

半导体级高纯双氧水中痕量杂质元素的检测

用高分辨电感耦合等离子体质谱测定半导体级高纯双氧水中的痕量金属杂质,用直接稀释法,把高纯双氧水稀释10倍后,用标准加入法进行上机检测,前处理简单、快速,避免了在样品前处理时的污染问题。高分辨电感耦合等离子体质谱可以消除多分子离子干扰,降低检出限,提高定量准确性。方法的检出限为0.34~15.36 ng/L,加标法回收率为90.1%~102.5%。方法简单,结果可靠,适用于高纯双氧水中痕量元素的快速测定。     

半导体级高纯氨水中痕量杂质元素的检测

用高分辨电感耦合等离子体质谱测定半导体级高纯氨水中的痕量金属杂质,用直接稀释法,把高纯氨水稀释10倍后,用标准加入法进行上机检测,前处理简单、快速,避免了在样品前处理时的污染问题。高分辨电感耦合等离子体质谱可以消除多分子离子干扰,降低检出限,提高定量准确性。该方法的检出限为0.31~14.4 ng/L,加标法回收率为91.5%~108.6%。该方法简单,结果可靠,适用于高纯氨水中痕量元素的快速测定。     

电感耦合等离子质谱法测定石英砂中十四种痕量杂质元素

文章根据不同石英砂的矿相、加工工艺,建立了密闭消解和微波消解等样品处理方法,利用电感耦合等离子体质谱仪（ICP-MS）对石英砂中痕量杂质元素进行检测。采用Sc为内标补偿基体效应和仪器漂移。检测结果表明,密闭酸溶法与微波消解法无显著性差异（P≥0.05）;ICP-MS检测石英砂中痕量杂质元素准确度和精确度高,检测线性范围宽,检出限低,分析快速。测定结果的相对标准偏差（RS D）0.2%～5.0%,检出限为0.009～0.093 ng/ml。     

气相色谱—质谱联用法对电子气中痕量氟化物的定性与定量

使用气相色谱—质谱联用法,采用全扫描模式,采取提取特征离子的方式对原始谱图进行处理,建立了电子气中微痕量氟化物杂质的定性、定量方法。检测限低、灵敏度高,单次进样,便可实现对多种氟化物杂质的定性和定量,且不受主成分的影响,是分析电子气中微痕量氟化物杂质高效精确的分析方法。     

砷化镓的二次离子质谱定量分析方法

化合物半导体由于其复杂的基体效应,给表面定量分析带来了很大困难。如何提高分析精度,对痕量元素作出定量分析,是定量分析的一个难点。近年来,随着半导体集成电路工业的发展和表面分析技术的进一步提高,出现了一些适用于砷化镓及其它半导体材料二次离子质谱定量分析的新方法。这里简要介绍了它们的特点、分析计算步骤和分析精度。根据不同情况,有选择地运用这些方法,可对砷化镓材料的背景杂质浓度及掺杂元素分布进行定量分析,可获得较好的精度,从而实现对材料制备和器件制作等工艺过程的监控。     

微波消解-石墨炉原子吸收光谱法测定纳米二氧化钛中痕量砷

建立微波消解-石墨炉原子吸收光谱法(GF-AAS)测定纳米二氧化钛中痕量杂质砷的分析方法,以快速完全消解二氧化钛基体并且准确测定痕量杂质砷。方法采用氢氟酸、硝酸混合试剂结合高压密闭微波加热技术,解决二氧化钛难消解和低酸度溶液中高钛基体容易水解等难点。通过基体效应影响试验,优选采用热解涂层石墨管,优化石墨炉升温原子化控制程序以及原子吸收光谱仪工作条件等检测参数,消除热稳定性强的二氧化钛基体对测定易挥发痕量元素砷的影响。结果表明:方法检出限为0.02μg/L,回收率为93.0%~106.0%,相对标准偏差9.36%,与ICP-MS检测方法结果对照一致。     

ICP-MS检测多晶硅基体中痕量元素分析的影响因素与控制措施

高纯多晶硅中的痕量杂质能够影响多晶硅的少子寿命,影响多晶硅的光学电学性能,所以,检测控制多晶硅中痕量杂质是保证多晶硅质量的重要指标。为保证高纯多晶硅中痕量元素的检测准确性,对实验过程中涉及到的水、容器、温湿度等因素进行研究,以确定这些因素的影响。结果表明:使用聚四氟乙烯材质的容器能够降低空白值,使用Milli-Q制水机制出的超纯水中的杂质比厂区生产的纯水低等。同时,对实验容器的清洗,溶剂的选择,人员的优化提出了相应的控制措施,确保所用的器皿、试剂等不受污染,尽量减小空白值。     

ICP-MS检测多晶硅表金属杂质的研究

应用电感耦合等离子体质谱仪(ICP-MS),对多晶硅料块表面金属杂质Fe,Cr,Ni,Cu,Zn,Na,元素进行检测。本文研究了样品的处理方法,确定了适宜的实验条件,使用该方法能准确、快速的检测多晶硅表面的金属杂质含量,适用于商用实验室中的检测,符合企业中工业化的检测需求。其检测方法对多晶硅中的金属杂质Fe,Cr,Ni,Cu,Zn,Na,元素的检出限达到0. 01ng/g左右,精密度较好,Fe的加标溶液的回收率为90!109%,满足痕量杂质检测的要求。     

金属浓缩取样器的研制

浓缩气相色谱法是一种测定痕量气体成分的方法,可用于测定高纯电子气中的痕量杂质。例如,测定高纯H_2、He中杂质灵敏度最低可到<0.01ppm。该方法过去采用的浓缩装置都是玻璃系统。玻璃取样器的缺点是易碎,过渡联接管多,易造成漏气。最近,我们经过研究,避免玻璃四通取样器的缺点,研制成金属浓缩取样器。本装置可用于H_2中痕     

Recent developments in analytical techniques for characterization of ultra pure materials—An overview

With continual decrease of geometries used in modern IC devices, the trace metal impurities of process materials and chemicals used in their manufacture are moving to increasingly lower levels, i.e. ng/g and pg/g levels. An attempt is made to give a brief overview of the use of different analytical techniques in the analysis of trace metal impurities in ultrapure materials, such as, high-purity tellurium (7N), high purity quartz, high-purity copper (6N), and high purity water and mineral acids. In recent times mass spectrometric techniques such as ICP-MS, GD-MS and HR-ICP-MS with their characteristic high sensitivity and less interference effects were proved to be extremely useful in this field. A few examples of such application studies using these techniques are outlined. The usefulness of other analytical techniques such as F-AAS, GF-AAS, XRF, ICP-AES and INAA was also described. Specific advantages of ICP-MS and HR-ICP-MS such as high sensitivity, limited interference effects, element coverage and speed would make them powerful analytical tools for the characterization of ultrapure materials in future.     

镓熔点温坪复现研究

镓熔点是ITS-90国际温标中重要的定义固定点,在温度计量研究中起着重要作用。由于高纯镓从液态转化为固态时,体积膨胀约3.1%,传统玻璃外壳的镓熔点容器在冻制过程中很容易造成损坏。为了解决这一难题,设计了一种具有金属外壳的镓熔点装置,以该装置为对象,开展了2种不同镓熔点复现方法和2种不同复现装置对镓相变温坪影响方面的研究,并与国外同类型装置的性能进行了比较。实验结果表明:不同镓点容器复现的镓熔点温度在0.02 mK范围内一致,高纯镓中的微量杂质是造成差异的主要原因;外液-固界面复现方法比双液-固界面复现方法得到的温坪值低0.09 mK;不同复现装置对镓熔点温坪的影响较小。     

High-temperature oxidation behaviour of base metal elements in nickel-base alloys

Oxidation of non-precious metals nickel, chromium and copper, nickel-base alloys in an air atmosphere was studied under differential thermal analysis. The results suggest that adding chromium and copper to high-purity nickel metal reduces the amount of oxidation and gives a slower oxidation than in untreated high-purity metals. It is then shown that the activation energy for oxidation in nickel-base alloys is almost the same as that in high-purity nickel metal when alloying elements are added to nickel.     

A high-speed quasi-optical wave phase switch based on the induced photoconductivity effect in silicon

A new microwave switch is proposed, in which the active element represents a metal reflector with a semiconductor plate on a mirror surface. The wave beam phase switching is ensured by a conducting layer formed in the semiconductor by laser radiation with quantum energy approximately equal to the bandgap width. Using a disk of high-purity silicon irradiated by a pulsed Ti:sapphire laser, a 180° phase switching in a 30-GHz wave beam has been studied. At a low microwave power level, the wave phase was effectively switched during a time on the order of several nanoseconds.     

痕量一氧化氮标准物质的研制

采用重量法研制了0.100μmol/mol的痕量氮中一氧化氮气体标准物质,其扩展不确定度为10%。在稀释气纯度分析时,采用标准添加法对纯化后的高纯氮中一氧化氮进行了准确定值,解决了痕量气体标准物质定值的难题。在长期稳定性考察时发现,气瓶中痕量一氧化氮量值随时间逐渐降低,1年内量值变化范围在4%~8%之间,并根据此结果进行了因素分析。     

Pinpoint and bulk electrochemical reduction of insulating silicon dioxide to silicon

Silicon dioxide (SiO(2)) is conventionally reduced to silicon by carbothermal reduction, in which the oxygen is removed by a heterogeneous-homogeneous reaction sequence at approximately 1,700 degrees C. Here we report pinpoint and bulk electrochemical methods for removing oxygen from solid SiO(2) in a molten CaCl(2) electrolyte at 850 degrees C. This approach involves a 'contacting electrode', in which a metal wire supplies electrons to a selected region of the insulating SiO(2). Bulk reduction of SiO(2) is possible by increasing the number of contacting points. The same method was also demonstrated with molten LiCl-KCl-CaCl(2) at 500 degrees C. The novelty and relative simplicity of this method might lead to new processes in silicon semiconductor technology, as well as in high-purity silicon production. The methodology may be applicable to electrochemical processing of a wide variety of insulating materials, provided that the electrolyte dissolves the appropriate constituent ion(s) of the material.     

Preparation of high-purity gallium from semiconductor fabrication waste

This review summarizes the results of systematic studies aimed at developing processes for the preparation of high-purity gallium from semiconductor fabrication waste. A classification is proposed for Gacontaining waste materials according to the host and impurity compositions. We compare the efficiencies of different processes for the fine purification of crude gallium recovered from waste materials: wet-chemical processing, vacuum heat treatment, filtration, electrorefining, and directional solidification. Taking into account the behavior of impurities during the purification process and the nature of the waste materials, we have developed a multistep, environmentally safe process for preparing high-purity (99.9999%) gallium from unconventional raw materials. The product of this process compares well with gallium produced from conventional raw materials. We demonstrate that the use of semiconductor fabrication wastes as raw materials in large-scale-production of high-purity gallium and related microelectronic products is a commercially viable approach.     

高纯六氟化钨的制备技术研究进展

随着电子工业迅速发展,六氟化钨被广泛应用于半导体行业,其需求量日益扩大,对其纯度要求也越来越苛刻。综述了现有六氟化钨最常用的制备及纯化方法,分析了这四种纯化方法各自优缺点。在实际生产中,应根据六氟化钨中所含杂质的种类,联用多种纯化方法来获得高纯六氟化钨产品。此外,应尽早实现高纯六氟化钨工业化生产,填补国内相关领域空白。     

热等离子射流法CO_2O_3/FeS催化裂解甲烷制备碳纳米管的研究

以CO_2O_3和FeS的混和物做催化剂前驱物,利用热等离子射流法制得包含碳纳米管的固相物,通过扫描电镜、透射电镜对产物进行表征并与高纯单质金属催化碳纳米管生长的类似文献报道做对比,证实其中碳纳米管密度大、纯度高、管径分布小、大部分为50～90nm的直线型多壁管且相互独立、管壁平滑、厚度约为10nm,在数量和质量上均可与已报道文献相比.结果表明,催化剂中微量氧的存在不仅不会影响催化效果,还有助于提高产物中碳纳米管纯度.     

Characterization of deep centers in semi-insulating SiC and HgI2: Application of discharge current transient spectroscopy

In order to characterize traps in semi-insulating 4H-SiC and HgI₂ regarded as an attractive semiconductor for X-ray detectors, we apply discharge current transient spectroscopy (DCTS), which is a graphical peak analysis method based on the transient reverse current of a diode. In high-purity semi-insulating 4H-SiC whose diode may detect X-rays or γ-rays, DCTS can detect two types of trap species, and can determine those densities and emission rates. The emission rates of detected traps are close to each other, suggesting that thermally stimulated current (TSC) may not distinguish between these two types of traps. In semi-insulating HgI₂, the densities and emission rates of two types of trap species are also determined by DCTS. Therefore, it is demonstrated that DCTS is a powerful method for determining the densities and emission rates of traps in semi-insulating semiconductors