Effect of F- and CH-Doped on Dielectric Properties of SiCOH Films Deposited by Decamethylcyclopentasiloxane Electron Cyclotron Resonance Plasma

We investigate the effect of CH-doped and F-doped on dielectric properties of SiCOH films deposited by de- camethylcyclopentasiloxane （DMCPS） electron cyclotron resonance plasma. The dielectric constant k is closely related to the configurations of films. For the films deposited only using DMCPS, the minimum k is as low as 2.88. By adding CH4 in the precursor, the k value can be reduced to 2.45 due to the film density decreasing by incorporating large size CHx groups. By adding CHF3 in the precursor, the k value can also be reduced to 2.48 due to the incorporation of the weak-polarization F atom. Thus the dielectric constant for SiCOH films depends on not only the film density but also the polarization of atoms. By increasing the film density or by reducing the polarization of atoms under the condition of a lower film density, the low dielectric constant SiCOH films can be obtained.     

Evolution of Structural Defects in SiOx Films Fabricated by Electron Cyclotron Resonance Plasma Chemical Vapour Deposition upon Annealing Treatment

We study the structural defects in the SiO, film prepared by electron cyclotron resonance plasma chemical vapour deposition and annealing recovery evolution. The photoluminescence property is observed in the as-deposited and annealed samples. [-SiO3]^2- defects are the luminescence centres of the ultraviolet photoluminescence （PL） from the Fourier transform infrared spectroscopy and PL measurements. [-SiO3]^2- is observed by positron annihilation spectroscopy, and this defect can make the S parameters increase. After 1000℃ annealing, [-SiO3]^2- defects still exist in the films.     

Atom-sensitive textiles as visual indicators for plasma post-discharges

The efficiency of surface treatments by plasma and post-discharge plasma processes is greatly dependent on the density of active species, such as neutral atoms in post-discharges. Therefore, many diagnostics exist to detect the presence and measure the concentrations of these species, but they often require expensive instrumentation and highly qualified personnel. These conditions are not often met when the process is industrially used and it becomes important to imagine simple indicators allowing to validate that the correct operating conditions are reached. In the present paper, we present the first results on the investigation of an inexpensive and easy to use visual indicator able to quantify the atomic species density in nitrogen post-discharge plasma processes. It is based on the differential recombination coefficients of N-atoms on metallic/textile fibres which are intrinsically bonded together in a fabric matrix which serves as support for a thermochromic ink. The specific heating of the metallic fibres by N-atom recombination heats the whole of the fabric, leading to a visible colour change of the thermochromic ink, and therefore, of the indicator. Through modelling, it was possible to estimate that the inclusion of copper fibres to a pure cotton matrix leads to a 60% increase of the global N-atom recombination coefficient of the fabric, sufficient enough to provide a clearly visible colour change.     

Inductively Coupled Plasma and Electron Cyclotron Resonance Plasma Etching of an InGaAlP Compound Semiconductor System

Current and future generations of sophisticated compound semiconductor devices require the ability for submicron scale patterning. The situation is being complicated because some of the new devices are based on a wider diversity of materials to be etched. Conventional RIE (reactive ion etching) has been prevalent across the industry so far, but has limitations for materials with high bond strengths or multiple elements. In this article, we suggest high-density plasmas such as ECR (electron cyclotron resonance) and ICP (inductively coupled plasma), for the etching of ternary compound semiconductors (InGaP, AlInP, AlGaP) that are employed for electronic devices such as heterojunction bipolar transistors (HBTs) or high electron mobility transistors (HEMTs), and photonic devices such as light-emitting diodes (LEDs) and lasers. Operating at lower pressure, high-density plasma sources are expected to meet target goals determined in terms of etch rate, surface morphology, surface stoichiometry, selectivity, etc. The etching mechanisms that are described in this article can also be applied to other III-V (GaAs-based, InP-based) as well as III-Nitride, because the InGaAlP system shares many of the same properties.     

共振离子化质谱在高纯材料表面杂质分析中的应用

用激光熔出－共振离子化质谱法测定纯铁中及高纯硅片表面的铬。测定含有１０１２原子／ｃｍ２Ｃｒ的信号强度表明本方法可测定低至１０９原子／ｃｍ２的样品，其空间分辨率为０．２ｍｍ，还可进行二维杂质元素分析。     

A Power Interruption Technique for Investigation of Temperature Difference in Stabilized Low Direct-Current Arc Burning in Pure Argon on Atmospheric Pressure

Plasma of argon stabilized arc column, in a current range 3-11 A, is investigated using emission spectrometric diagnostic techniques. Temperatures are evaluated using several methods： argon line to adjacent recombinational continuum intensity ratio, absolute emissivity of argon line, measurement of electron number density, and power interruption. Electron number density is evaluated from absolute emissivity of recombinational continuum. The difference between electron Te and heavy particle Th temperature ranged from 4500 K for 3 A to 2300 K for 11A arc current. By comparing the present with the previously obtained results, using the same arc device but with the introduction of water aerosol, it is concluded that water aerosol reduces the difference Te - Th and brings plasma closer to the partial thermodynamic equilibrium state.     

激光诱导等离子体中Al原子共振双线时-空演化的实验研究

通过测定激光诱导等离子体中Ａｌ人振双线３９６．１５ｎｍ和３９４．４０ｎｍ强度的时－空演化特性，对激光诱导等离子体中共振双线的演化规律及其机理进行了讨论，使用的气体是空气气压为１０１ｋＰａ。     

质谱法测定多糖结构的机理研究

用气相色谱－质谱法对多糖的结构进行了测定，并着重对质谱法测定多糖结构的机理进行了研究。     

Thermal Ionization and Inductively Coupled Plasma Mass Spectrometry: Potential for Application to Studies on the Biokinetics of Molybdenum in Humans

Abstract

The use of stable isotopes as tracers in biokinetic investigations provides a means to obtain important metabolic data directly in humans without exposing the subjects to undue risks. In this work, three types of mass spectrometers are compared with regard to the determination of the abundances of stable isotopes of molybdenum in natural and enriched aqueous samples. The data show a good response of thermal ionization mass spectrometry (TIMS) and of high-resolution inductively coupled plasma mass spectrometry (ICPMS) to the isotopic enrichment of the samples, whereas conventional quadrupole ICPMS shows an unsatisfactory reproducibility of the results. Moreover, only TIMS can achieve an accuracy of better than 1% for the obtained isotopic ratios. Although a tedious procedure for the preparation of the biological samples is required and less sensitivity is achieved as compared to ICPMS, TIMS still seems to be method of choice for the accurate assessment of isotope ratios as required in multitracer studies on human biokinetics of trace metals.