扇聚焦等时性回旋加速器性能的改进和提高

安装了ＥＣＲ离子源及其外注入系统后，增加了离子种类、提高了束流强度。扇聚焦等时性回旋加速器（ＳＦＣ）主要工作点分布于三次谐波加速区域，为了匹配外注入系统，仔细地研究了中心区，重新设计加工了Ｄ盒及假Ｄ。为了改进ＳＦＣ性能，提高运行效率，同时进行了其它改进工作。介绍了改进后的ＳＦＣ的调束工作。     

Characterization of tantalum oxy-nitrides deposited by ECR sputtering

We have investigated the electrical characteristics of tantalum oxy-nitride (TaON) films deposited using electron cyclotron resonance (ECR) plasma sputtering. A pure tantalum metal target was used as raw material combined with gases of oxygen and nitrogen. The electrical properties have been measured using metal-insulator-metal (MIM) structures of Al/TaON/Ru/Si or metal-insulator-semiconductor (MIS) structure of Al/TaON/Si. By controlling the oxygen gas flow in a moderate low gas flow rate at fixed nitrogen gas flow, TaON films have been stably obtained with the refractive indices of over 2.5 at 632.8 nm wavelength, and the dielectric constants of over 30. However, the leakage currents have increased with an increase in the dielectric constants. To improve the leakage current, we have investigated the periodical deposition process, in which the ECR plasma irradiation was additionally introduced after thin TaON film was deposited. The breakdown strength of about 1 MV/cm was obtained by the measurement using MIM structure. By the estimation of the C-V characteristics of the silicon-MIS structure using TaON, the dielectric constant of 34 was obtained for a TaON thickness of 12 nm.     

Ion beam-assisted planarization of chemically vapor deposited diamond thin films using electron cyclotron resonance plasma

The high inherent surface roughness of as-deposited polycrystalline diamond films has made effective planarization processing of these films essential for most industrial applications. We have investigated the efficacy of ion beam sources for planarization in an electron cyclotron resonance plasma system using both direct substrate biasing and an accelerating grid system. Rough polycrystalline diamond films were synthesized using hot filament chemical vapor deposition. Both the etching rates and the resultant surface roughnesses were found to decrease as the angle of incidence (relative to the substrate surface normal) of the ion beam was increased. In the case of direct biasing of the sample, acicular features were observed following processing at higher incident angles. The use of double ion-extraction grids in conjunction with concomitant sample rotation was found to produce more uniform planarization of the diamond films. The rate of surface roughness reduction was found to be nonlinear and decreased with time. For both ion extraction methods investigated, the average film roughness (R_a) was significantly reduced from 0.2 to 0.05–0.06 μm.     

Electrochemical analysis and convection-enhanced mass transfer synergistic effect of MnOx/Ti membrane electrode for alcohol oxidation

The different electrocatalytic reactors could be constructed for the electrocatalytic oxidation of 2,2,3,3-tetrafluoro-1-propanol(TFP) with two typical MnO_x/Ti electrodes, i.e.the electrocatalytic membrane reactor(ECMR) with the Ti membrane electrode and the electrocatalytic reactor(ECR) with the traditional Ti plate electrode.For the electro-oxidation of TFP, the conversion with membrane electrode(70.1%) in the ECMR was 3.3 and 1.7 times higher than that of the membrane electrode without permeate flow(40.8%) in the ECMR and the plate electrode(21.5%) in the ECR, respectively.Obviously, the pore structure of membrane and convection-enhanced mass transfer in the ECMR dramatically improved the catalytic activity towards the electro-oxidation of TFP.The specific surface area of porous electrode was 2.22 m~2·g~(-1).The surface area of plate electrode was 2.26 cm~2(1.13 cm~2× 2).In addition, the electrochemical results showed that the mass diffusion coefficient of the MnO_x/Ti membrane electrode(1.80 × 10~(-6) cm~2·s~(-1)) could be increased to 6.87 × 10~(-6) cm~2·s~(-1) at the certain flow rate with pump, confirming the lower resistance of mass transfer due to the convection-enhanced mass transfer during the operation of the ECMR.Hence, the porous structure and convection-enhanced mass transfer would improve the electrochemical property of the membrane electrode and the catalytic performance of the ECMR,which could give guideline for the design and application of the porous electrode and electrochemical reactor.     

Study of tribological performance of ECR-CVD diamond-like carbon coatings on steel substrates: Part 2. The analysis of wear mechanism

This paper describes the tribological performance of diamond-like carbon (DLC) coatings deposited on AISI 440C steel substrates by electron cyclotron resonance chemical vapor deposition (ECR-CVD) process. A variety of analytic techniques were used to characterize the coatings, such as Raman spectroscopy, atomic force microscopy (AFM) and nano-indentation. The sliding wear and friction experiments were carried out by the conventional ball-on-disk tribometry against 100Cr6 steel counterbody at various normal loads (1-10 N) and sliding speeds (2-15 cm/s). All the wear tests were conducted under dry sliding condition in ambient air for a total rotation cycle of 1 × 10⁵ (sliding distance ∼2.2 km). Surfaces of the coatings and the steel balls were examined before and after the sliding wear tests. The DLC coatings that had been tested all showed relatively low values of friction coefficient, in the range of 0.1-0.2 at a steady-state stage, and low specific wear rates (on the order of 10⁻⁸ mm³/Nm). It was found that higher normal loads or sliding speeds reduced the wear rates of the coatings. Plastic deformation became more evident on the coating surface during the sliding wear test at higher contact stresses. The friction-induced transformation of the coating surface into a graphite-like phase was revealed by micro-Raman analysis, and the flash temperature of the contact asperities was estimated. It was suggested that the structural transformation taking place within the wear tracks was mainly due to the formation of compact wear debris layer rather than the frictional heating effect. On the other hand, an adherent transfer layer (tribolayer) was formed on the counterface, which was closely related to the steady-state friction during sliding and the wear mechanisms. Fundamental knowledge combined with the present tribological study led to the conclusion that adhesive wear along with abrasion was probably the dominant wear mechanism for the DLC/steel sliding systems. Additionally, fatigue processes might also be involved in the wear of the coatings.     

类金刚石薄膜的反应离子刻蚀

为了刻蚀出图形完整、侧壁陡直、失真度小、独立的类金刚石薄膜微器件,反应离子刻蚀是一种有效地刻蚀方法。研究了氧气与氩气的混合气体进行类金刚石薄膜刻蚀的主要工艺参数(刻蚀时间、有无掩膜、氩氧体积混合比、负偏压)。研究结果表明:在相同条件下,刻蚀速率随刻蚀时间变化不大;有无掩膜对刻蚀速率无明显影响;流量一定时,刻蚀速率随氩氧体积比的增大而降低,随负偏压的增大先增大后减小。实验得到最佳刻蚀条件,在此条件下,刻蚀出图形完整、侧壁陡直、失真度小的微器件,并成功制备出"独立"的微齿轮,进行了组装。     

硅片纳米微粒清洗洁净新技术

随着半导体技术的不断发展,集成电路的线宽正在不断减小,对硅片表面质量处理的要求也就越来越高.传统的湿法清洗已经不能满足要求,故必须研发新的微粒清洗方法.简述了硅片表面污染物杂质的类型、传统的微粒湿法清洗法和干法清洗法,然后在此基础上分析了几种硅片制备工艺中纳米微粒的去除新技术,包括低温冷凝喷雾清洗工艺,N2O电子回旋加速共振等离子系统清洗技术,以及超细晶圆质量无危险的清洗方法等.     

Microwave ECR plasma CVD of cubic Y2O3 coatings and their characterization

Yttrium oxide (Y₂O₃) thin films are deposited by microwave electron cyclotron resonance (ECR) plasma assisted metal organic chemical vapour deposition (MOCVD) process at a substrate temperature of 350 °C using indigenously developed metal organic precursors (2,2,6,6-tetra methyl-3,5-heptane dionate) yttrium, commonly known as Y(thd)₃ synthesized by ultrasound method. The deposited coatings are characterized by X-ray photoelectron spectroscopy, glancing angle X-ray diffraction, scanning electron microscopy, EDS and infrared spectroscopy. The characterization results indicate that it is possible to deposit non-porous coatings with excellent uniformity of a single phase cubic Y₂O₃ on various substrates by this process at reasonably low substrate temperature that is desirable in various manufacturing processes.     

CIAE强流ECR离子源研制

本文介绍了研制的一台强流ECR微波离子源,其能从7 mm直径的圆孔引出大于150 mA的氢离子束(75 keV),质子比达90%。该离子源采用独特的结构提高了离子源寿命。离子源在75 keV、110 mA束流条件下连续工作超过220 h,束流中断2次,不间断工作时间超过150 h。     

Simulation of ECR Startup and Comparison with Experimental Observations in SUNIST

Transient process of ECR startup in SUNIST with a one-dimensional model is analyzed and simulated. Contributions from the generation, drift, diffusion and loss of electrons are taken into account in the model and estimated from experimental parameters, e.g., toroidal field, vertical field and gas filling pressure. Typical discharges are simulated with the conditions close to the experiomental ones. Both experimental and simulated results are comparable qualitatively in amplitudes and semi-quantitatively in time. From the results it is confirmed that the transient process of ECR startup in SUNIST is dominant, as preliminarily deduced from experimental observations, by a pair of exclusive factors, namely the absorption, due to gas ionization, and the reflection of microwave, caused by the shift of over dense plasmas due to outward E×B drift. In addition to these two factors, electron loss along the field line is also very important in determining the character of discharges.