硅单晶片中的氧及对后续缺陷的影响

通过测量硅晶棒不同部位的氧含量,分析了氧在硅晶棒中的分布规律。结合高温氧化后的缺陷观察结果,研究了氧含量及后续高温生产工艺对硅晶体中缺陷数量的影响。对不同氧含量的两种硅单晶片所生产的功率集成电路进行了失效分析。结果表明,硅单晶片中的氧含量对产品成品率具有重要影响。当氧含量在1.77×10¹⁸~1.87×10¹⁸atoms/cm³及以上时,硅单晶片边缘出现明显的位错排,断面存在大量层错和位错缺陷,部分缺陷进入外延层中的晶体管,造成该处晶体管结漏电。相反,当氧含量偏低时,硅单晶片内的缺陷较少且分布不均,使得硅单晶片受到金属污染时不能有效吸杂而产生失效。     

Site-specific immobilization of flavin adenine dinucleotide on indium/tin oxide electrodes through flavin adenine amino group

A Mannich-type reaction was used to attach flavin adenine dinucleotide (FAD) covalently to aminosilane derivatized indium/tin oxide-coated glass plates. The aminosilane was activated with formaldehyde to give an intermediate that attached specifically to the adenine amino group of FAD. The presence of the intermediate also was demonstrated by coupling hydroquinone to the formaldehyde activated support. The immobilized FAD and hydroquinone were characterized by cyclic or differential pulse voltammetry. The immobilized FAD was shown to reduce the overpotential for NADH oxidation by 180 mV. In keeping with results for FAD on glassy carbon, FAD attached to indium/tin oxide at the adenine amino group did not lead to reconstitution of activity with apoglucose oxidase. On leave from University of Madras, India.     

Dimethyl(tetramethylcyclopentadienyl)silyl-, -germyl- und -stannyl-phosphane. Röntgenstrukturanalyse von Chloro(dimethyl)tetramethylcyclopentadienylstannan und Tetracarbonyl[1-dimethyl-(tetramethylcyclopentadienyl)germyl-3,4-dimethylphospholen]eisen(0)

Dimethyl(tetramethylcyclopentadienyl)silyl-, -germyl-, and -stannylphosphanes. X-Ray Structures of Chloro(dimethyl)tetramethylcyclopentadienyl-stannane and Tetracarbonyl[1-dimethyl(tetramethylcyclopentadienyl)germyl-3,4-dimethyl-phospholene]iron(0) Me₂Cp′SiCl ( 1 ) (Cp′ = C₅HMe₄) reacts with magnesium and R₂PCl (R = Ph, ^tBu) as well as PCl₃ in tetrahydrofurane yielding Me₂Cp′SiPPh₂ ( 4 ), Me₂Cp′SiP^tBu₂ ( 5 ) and (Me₂Cp′Si)₃P ( 6 ) respectively. The reaction of Me₃SiPPh₂ ( 7 ) or Me₃SiPC₄H₄Me₂ ( 10 ) with Me₂Cp′GeCl ( 2 ) and Me₂Cp′SnCl ( 3 ) leads to the formation of Me₂Cp′EPPh₂ (E = Ge ( 8 ), Sn ( 9 )) and Me₂Cp′EPC₄H₄Me₂ (E = Ge ( 11 ), Sn ( 12 )). 11 reacts with Fe(CO)₅ with formation of Fe(CO)₄[(PC₄H₄Me₂)GeCp′Me₂] ( 13 ). 3 crystallizes in the space group P2₁/n with a = 986,7(1), b = 1247,3(2), c = 1028,2(1) pm, β = 92,71(1)°, Z = 4 and V = 1264,1(2) 10^?30 m³. The final refinement resulted in R₁ = 0,0249 for 2097 observed reflexions with F_o ≥ 4σ(F_o). 13 crystallizes in the space group P2₁/n with a = 967,7(3), b = 1298,70(16), c = 1832,7(3) pm, β = 95,810(19)°, Z = 4 and V = 2291,4(8) 10^?30 m³ (R₁ = 0,0444 for 4043 observed reflexions with F_o ≥ 4σ(F_o). 13 forms a trigonal bipyramide with the phosphane ligand 11 in an axial position.     

缺陷LB膜诱导特异形貌草酸钙堆积图形

A special pattern of calcium oxalate monohydrate (COM) crystals was induced by DPPC Langmuir-Blodgett films with defects. The pattern was that a large hexagonal COM crystal located in the middle of a ring-shaped pattern of needle-liked crystals. The number of such special patterns with a diameter between 10 μm and 40 μm accounted for about 5% of the whole crystal patterns. It is due to the “islands” composed of aggregated film-forming molecules in the middle of the liquid-condensed domains. The effects of the concentration of potassium oxalate and the growth time on the crystal patterns were studied. When the concentration of potassium oxalate(c_K2C2O4) was 0.6 mmol·L^-1, the needle-liked COM crystals on the rings grew towards inside part of the patterns as the induced-time increased from 1 h to 4 h. After 2 h, the solid circle patterns were formed. On the other hand, the size of the hexagonal COM crystal in the middle of the pattern increased. The size of the COM crystals on the rings were about 3 μm × 2 μm, and that of three-dimensional COM crystals in the middle of the patterns were about 16 μm × 7 μm × 6 μm after 4 h. However, when c_K2C2O4 was increased to 5.0 mmol·L^-1, there was only a large COM crystal grown in the middle of the circular COM crystallites no matter 1 h or 4 h of crystal growth, and the ratio of these special COM patterns increased. It can be explained that the interaction between oxalate and DPPC molecules is enhanced as the increase of c_K2C2O4, so more and more DPPC molecules fled away from the substrate surface, resulting in decrease of the nucleating sites in the circle.     

Zur Neuuntersuchung des Phasendiagramms InI—SnI2

Redetermination of the Phase Diagram InI—SnI₂ The phase diagram of the system InI—SnI₂ was redetermined with DTA and X-ray methods. We found that the compound given in the literature by the formula In₄SnI₆ is not formed. Instead of this a phase with lower InI content and having the composition In₃SnI₅ could be established, which crystallizes in three different low temperature polymorphs. This compound transforms to yet another, high temperature polymorph to 247^°C. Additionally a ternary compound with the formula Insn₂I₅ could be observed in the system InI—SnI₂, which has the tetragonal NH₄Pb₂Br₅ structure.     

XPS Study of the Corrosion Protection of Fluorozirconate Glasses Dip-Coated with SnO2 Transparent Thin Films

Tin oxide nanoparticles prepared by an aqueous sol–gel method were deposited by dip-coating on fluorozirconate glass, ZBLAN (53%ZrF₄-20%BaF₂-4%LaF₃-3%AlF₃-20%NaF) to improve its resistance against wet corrosion. The aqueous leaching of uncoated and SnO₂-coated fluorozirconate glass was studied by X-ray photoemission spectroscopy (XPS) and it was shown that even an ultra thin tin dioxide film provides good protection of the glass surface against the bulk propagation of the hydrolytic attack.     

Influence of Elaboration Parameters on the Properties of Tin Oxide Films Obtained by the Sol-Gel Process

The influence of elaboration parameters during the sol-gel process is studied for tin oxide films deposition. The Dip Coating Sol-Gel route can be divided into three elaboration stages: the pulling phase and the drying and densification steps. During the pulling phase, the relative humidity ratio and the withdrawal speed are found to influence the film morphology and the film thickness respectively. Then, we show how a correct control of the sample drying is able to eliminate cracks. The densification step (temperature and duration), leading to the final network, is considered in details, and resulting effects on physical properties are presented: crytallinity, optical behaviour, atomic density, stoichiometry, electrical conductivity etc... We show through these results the specificity of the tin oxide elaborated with our procedure     

Employing sulfide-conductive solid electrolytes for the production of semiconducting sulfides with controlled composition and properties

Nonstoichiometry of sulfides of cadmium and lead is studied by the method of coulometric titration in electrochemical cells with sulfide-conductive solid electrolytes on the basis of MLn₂S₄. The range of the homogeneity region is estimated at temperatures 300 to 400°C. A feasible model for the formation of defects in nonstoichiometric sulfides of cadmium and lead is proposed.     

蒸镀薄膜的分形生长行为

自Mandelbrot的分形几何学问世以来,分形理论的应用日趋广泛。在薄膜生长方面亦是如此。真空蒸镀薄膜的生长遵循着一定的规律。基本上是:(1)成核在此期间形成小的晶核,它们按统计规律分布(有一些例外)在基片表面上;(2)晶核生长并形成较大的岛这些岛通常具有小晶体(微晶)的形状;(3)岛(微晶)和岛(微晶)之间聚集并形成含有空沟道的许多连接着的网络;(4)沟道被填充,形成连续的薄膜。