激光剥蚀-电感耦合等离子体质谱法测定多晶硅中杂质元素

采用激光剥蚀固体进样技术结合电感耦合等离子体质谱法测定了多晶硅中的元素B、Cu和Zn。考察了该三种杂质元素在多晶硅样品不同深度层面和同一深度层面的分布情况;尝试了采用硅基体信号归一化的方法计算了测定元素的含量。结果表明,杂质元素B、Cu和Zn在多晶硅材料中分布均匀,且测定结果与辉光放电质谱法的测定结果相吻合。这一方法可用于判别多晶硅表面的污染情况,以及杂质元素在多晶硅材料内部分布的均匀性。     

Behaviour of transuranium elements in the environment

The distribution and migration of Chenobyl plutonium have been studied in the ecosystem. Its behaviour is discussed.     

Neutron activation analysis of semiconductor silicon

The determination of impurities in semiconductor silicon by nondestructive and destructive NAA is described. To improve the detection limit, a multiple beta—single gamma detector assembly is used. It is shown that²⁴Na is also produced from silicon by a (n, αp) reaction with reactor neutrons. The cross-section with fission neutrons is 1.8·10⁻⁹ barn.     

Chemical bonding and structure of metastable impurity centers in semiconductor crystals

The properties of metastable impurity centers in semiconductor crystals [III-V, II-VI, IV-VI, and II-VII (CF₂)] are considered. Much attention has been focused on modification of the chemical bond of a regular crystal in the presence of doping atoms and on the effect of this modification on the structure (including the electronic structure) of the impurity center. Some general consistencies in reconstruction of the metastable impurity centers due to variation of their charged state are revealed. Translated fromZhurnal Strukturnoi Khimii, Vol. 41, No. 4, pp. 813-838, July-August, 2000.     

Chemical bonding and structure of metastable impurity centers in semiconductor crystals

The properties of metastable impurity centers in semiconductor crystals [III-V, II-VI, IV-VI, and II-VII (CF₂)] are considered. Much attention has been focused on modification of the chemical bond of a regular crystal in the presence of doping atoms and on the effect of this modification on the structure (including the electronic structure) of the impurity center. Some general consistencies in reconstruction of the metastable impurity centers due to variation of their charged state are revealed. Translated fromZhurnal Strukturnoi Khimii, Vol. 41, No. 4, pp. 813-838, July-August, 2000.     

The d-electron states of iron group impurity atoms in silicon

The question of the relative arrangement of the crystalline terms is considered, within the framework of crystal field theory, as a function of the location of the impurity atom in the silicon. The results of the corresponding calculations are found to agree with the experimental data.     

Interlaboratory comparison of INAA of semiconductor silicon

In an interlaboratory comparison four samples of monocrystalline silicon were analyzed sequentially by INAA in four laboratories. The results obtained demonstrate the possiblity of repeated use of silicion samples for interlaboratory comparisons. *** DIRECT SUPPORT *** A0653052 00003     

萃取分离ICP-AES法测定含锆铀铌合金中的杂质元素

研究了在HNO3介质中用磷酸三丁酯(TBP)同时萃取铀和锆,鞣酸沉淀铌的分离条件。电感耦合等离子体原子发射光谱(ICP AES)法同时测定了含锆铀铌合金中铁、铜、锰、硅、铝和镍6种杂质元素。测定范围在10～1000μg/g之间,回收率为97%～106%,相对标准偏差为5%～10%。     

Activation analysis and autoradiography of impurity distributions in silicon multilayer structures

Activation analysis and autoradiography were used to investigate the concentration distribution of contaminants in poly-Si−Si₃N₄−SiO₂−Si substrate multilayer structures (SNOS) on sampling each technological product. Samples were irradiated for 36 hrs at a thermal neutron flux of 4·10¹³n·cm⁻²·sec⁻¹. The thin films of the analysed sample were removed stepwise by selective chemical etching using appropriate masking techniques. Simultaneously autoradiographs were made of the surface of parallel samples activated under the same conditions. The concentration of the technological contaminants (e.g. Na, Cu, Au) increases in the junction interface of the layers as unambiguously shown by the results obtained. Presented at the “4th Symposium on the Recent Developments in Neutron Activation Analysis” Churchill College, Cambridge, 4–7 August, 1975.     

Piezoresistive elements of polycrystalline semiconductor thin films

Polycrystalline Si and Ge films have been prepared by the CVD method and have been used as sensing elements of pressure sensors that have a semiconductor/insulator/stainless steel structure. Values of the gauge factor were 20 and 30 for polycrystalline Si and Ge films, respectively. Hysteresis and deviation from linearity were less than 0.6%.     

X射线荧光法测定纯铝制品中的杂质元素

本文主要介绍铝粒、铝线、铝块等纯铝制品中主要杂质元素的X射线荧光测定法。利用光谱标准物质,优化分析条件,建立纯铝制品中各杂质元素的分析曲线, 此方法精密度好,准确度高,操作简便、快速,能够适应生产快速检验的需要。     

Determination of antimony dopant and some ultra-trace elements in semiconductor silicon by atomic absorption spectrometry with introduction of solid samples into the furnace

Antimony as a dopant at a level of ca. 35 atom/10⁶ atoms (ppm, atomic) and ultra-trace concentrations of lead and manganese (<0.02 ppm, atomic) are determined in semiconductor silicon by atomic absorption spectrometry after introduction of milligram samples of silicon to a pyrolytically-coated graphite furnace. Calibration was done with standard aqueous solutions. Iron, silver, zinc and cadmium were sought but were at concentrations below the limits of detection. The graphite microboats used for sample introduction were useful for only 3–10 samples because of silicon carbide formation.     

萃取分离 ICP-AES 法测定含铪铀中微量杂质元素

用盐酸-硝酸-氢氟酸溶解含铪的铀试样,以磷酸三丁酯为萃取剂,分离铀、铪与待测杂质元素.用 ICP-AES 法同时测定了试样中钼、钨、铁、硼、锰、铍、铜、镁、钙、铝和镍等11种杂质元素的含量.将 0.0900 g～0.1100 g 试样制成 6 mL 溶液时,各杂质元素测量范围为 1.0×10-3%～1.0×10-1%,回收率在 94%～105% 之间,相对标准偏差优于 10%.     

锆存在时铀中杂质元素的化学分离-ICP-AES法

采用磷酸三丁酯（TBP）－氢化煤油萃取油、过氧化氢掩蔽钛、磷酸氢二铵沉淀锆的方法，用ICP－AES法同时测定了锆存在在时铀中的铁、锰、铜、硅、铝、镍和钛7种杂质元素的含量。当测定范围在100μg/g-1000μg/g时，相对标准偏差＜9．0％，回收率为96％－109％。     

Instrumental neutron activation analysis of semiconductor grade silicon

The single comparator method in neutron activation analysis has been applied to the investigation of the purity of silicon single-crystals of different origins. The following impurities were determined: Au, Sb, Co, Cu and Na. Studies were also carried out on the surface contamination of silicon samples introduced through steps of sample preparation and irradiation. Up to nineteen elements on the surface of samples were analysed and found to be easily reduced to low levels or detection limits by washing and etching.     

Spectrographic determination of trace elements in solar-grade silicon

Summary An optical emission spectrographic method is described for the estimation of fourteen trace metallic impurities such as B, Pb, Sn etc., in solar-grade silicon. The silicon is ground under liquid nitrogen, then mixed with high-purity graphite powder and sodium fluoride (the latter to improve the line-to-background ratio). The mixture is excited in a d. c. arc (12 A) in a nitrogen atmosphere. The spectra of the sample and standards over the wavelength region 2400–3350 Å are photographed. The detection limits for the various elements range from 1 to 25 ppm. A matrix line of silicon is chosen as the internal standard. The mean coefficient of variation in the determination of the various elements is between 9 and 24%.

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Spektrographiscbe Bestimmung von Spurenelementen in Solarzellensilicium

Zusammenfassung Eine emissionsspektrographische Methode zur Bestimmung von 14 Spurenelementen wie Bor, Blei, Zinn usw. in Solarzellensilicium wurde beschrieben. Das Silicium wird unter flüssigem Stickstoff zerkleinert und dann mit hochreinem Graphitpulver und Natriumfluorid gemischt. Letzteres dient zur Verbesserung des Verhältnisses Linie zu Untergrund. Das Gemisch wird im Wechselstrombogen (12 A) in Stickstoff atmosphäre angeregt. Die Spektren der Probe und der Standards zwischen 2400 und 3350 Å werden photographiert. Die Nachweisgrenzen für die verschiedenen Elemente liegen zwischen 1 und 25 ppm. Eine Linie der Silicium-Matrix dient als interner Standard. Der Variationskoeffizient bei der Bestimmung der verschiedenen Elemente liegt zwischen 9 und 24%.

     

Separation of iron from semiconductor grade silicon in activation analysis

A method of separation of iron from silicon for use in the neutron activation analysis has been developed. Iron was separated by extraction with N-benzoyl-N-phenylhydroxylamine /HBPHA/ from 0.4N HCl solution followed by extraction at pH=3.0. The lower limit of determination was 9.9×10^–9 g.     

Bulk electrochemical etching of semiconductor single-crystal silicon in HF-containing solutions

Effect of the component composition of an HF-containing electrolytic aqueous solution on the polishing electrochemical etching of semiconductor single-crystal silicon was studied. Propanol-2, SV-1017, and NH₄F served as additional components of solutions used for this purpose. The conditions in which this process can be employed to form elements with 3D structure in microsystems devices were determined. An analysis of the results obtained led to an assumption that the hydrogen passivation of the surface of semiconductor single-crystal silicon is the rate-determining factor affecting the development of a bulk polishing electrochemical etching of this material. Because the process of polishing electrochemical etching of silicon wafers is preserved during approximately 20 min, the method is acceptable for formation of shallow grooves in microsystems devices.