improvement of electrical properties of Cu/SiCOH low-k film integrated system by O2 plasma treatment

This paper investigates the effect of O2 plasma treatment on the electric property of Cu/SiCOH low dielectric constant （low-k） film integrated structure. The results show that the leakage current of Cu/SiCOH low-k integrated structure can be reduced obviously at the expense of a slight increase in dielectric constant k of SiCOH films. Bythe Fourier transform infrared （FTIR） analysis on the bonding configurations of SiCOH films treated by O2 plasmar it is found that the decrease of leakage current is related to the increase of Si-O cages originating from the linkage of Si dangling bonds through O, which makes the open pores sealed and reduces the diffusion of Cu to pores.

Controlling coffee ring structure on hydrophobic polymer surface by manipulating wettability with O2 plasma

A simple and novel method is firstly reported for controlling coffee ring structure on polystyrene（PS）film surface by O2 plasma. O2 plasma treatment leads to the wettability change of PS surface from hydrophobic to hydrophilic. For hydrophilic PS surface the coffee ring structure is avoided relying on the motion of contact line（CL） while SiO2 microspheres are left. The motion of the CL is produced based on the viscosity and Marangoni effect with the addition of polymer additives. For hydrophobic PS surface coffee ring structure still persists even with polymer additives because SiO2 microspheres transfer with the motion of the CL at the beginning of droplet evaporation and accumulate at the droplet edge at late stage with the pinning of the CL. As a result, uniform and macroscale SiO2 microspheres deposition without coffee ring structure and SiO2 microspheres deposition with coffee ring structure are controlled by O2 plasma. This method provides a new way to tune coffee ring structure with smart surface and may be potentially useful for a range of application at material deposition and diagnosing diseases.

PMMA人工晶状体表面的CF4/O2等离子体修饰

为了改善聚甲基丙烯酸甲酯(PMMA)人工晶状体的生物相容性和透光性,采用CF4/O2等离子体技术修饰其表面.通过衰减全反射红外光谱(ATR-FTIR)、X射线光电子能谱(XPS)、静态接触角(CA)测定、扫描电子显微镜(SEM)、紫外-可见近红外光谱(UV-Vis)等方法进行表征,结果表明,经CF4/O2等离子体处理后,PMMA表面的含氟和含氧基团增加,其表面的亲水性增强,生物相容性改善,紫外光的隔离效率增大.因此,通过CF4/O2等离子体修饰能够有效地改善PMMA人工晶状体的性质.

Comprehensive Study of SF_6/O_2 Plasma Etching for Mc-Silicon Solar Cells

The mask-free SF6/O2 plasma etching technique is used to produce surface texturization of mc-silicon solar cells for efficient light trapping in this work. The SEM images and mc-silicon etching rate show the influence of plasma power, SF6/O2 flow ratios and etching time on textured surface. With the acidic-texturing samples as a reference, the reflection and IQE spectra are obtained under different experimental conditions. The IQE spectrum measurement shows an evident increase in the visible and infrared responses. By using the optimized plasma power, SF6/O2 flow ratios and etching time, the optimal etticiency of 15.7% on 50 × 50mm2 reactive ion etching textured mc-silicon silicon solar ceils is achieved, mostly due to the improvement in the short-circuit current density. The corresponding open-circuit voltage, short-circuit current density and fill factor are 611 m V, 33.6 mA/cm2, 76.5%, respectively. It is believed that such a low-cost and high-performance texturization process is promising for large-scale industrial silicon solar cell manufacturing.

Effects of O_2 Plasma Treatment on the Chemical and Electric Properties of Low-k SiOF Films

With the progress of ULSI technology, materials with low dielectric constant are required to replace SiO2 film as the interlayer to scale down the interconnection delay. Fluorinated Si oxide thin films (SiOF) are a promising material for the low dielectric constant and the process compatibility in existing technology. However, SiOF films are liable to absorb moisture when exposed to air. By treating the SiOF films with O-2 plasma, it was found that the moisture resistibility of SiOF films was remarkably improved. The mechanism of the improvement in stability of dielectric constant was investigated. The results show that: 1) F atoms dissociated from the films and the bond angle of Si-O-Si decreased. 2) The plasma treatment enhanced the strength of Si-F bonds by removing unstable =SiF2 structures in the films. Resistibility of SiOF films in moisture was improved.

Comparison of Structures and Properties between Wool and Ramie Fibers Treated by Atmospheric Pressure Ar and Ar/O_2 Plasma

The technique of atmospheric pressure plasma is of value in textile industry.In this paper,argon(Ar)and argon/oxygen(Ar/O2)atmospheric pressure plasma were used to treat wool and ramie fibers.The structures and properties of treated fibers were investigated by means of SEM,XPS,single fiber tensile tester and so on.The results proved that the effects of plasma treatments depended on structural characteristics of fibers to a great extent,besides conditions of plasma treatment.By atmospheric pressure plasma treatment,wool fiber had significant changes in morphology structure,surface chemical component,mechanic properties and dyeability,while ramie fiber just showed a little change.In additional,Ar/O2 plasma showed more effective action than argon.And at the beginning of treatment,plasma brought about remarkable effects,which did not increase with prolonging of treat time.

Fabrication of low-loss SiO2/Si channel waveguides by roughness reduction

An experimental study of the dependence of SiO2 waveguide side wall roughness on the etch condi- tions and etch masks in CHF3/O2 based reactive ion etching plasma was reported. When working under standard low-pressure （20mtorr） etching conditions, a novel etch roughening phenomenon has been observed in the plasma, that is, the roughness of the etched front surface increases with the amount of material etched, independent of etch rate, RF power, and gas composition. Besides, the etched underlying side wall will be tapered as the upper SU-8 resist pattern degradation transfers downward. A process using double-layered mask, consisting of SU-8 resist and thin Chromium film, was developed for improving the side wall smoothness. Based on the studies, SiO2/Si channel waveguides with the propagation loss less than 0. 07dB/cm were fabricated at last.

Fabricating GeO_2 passivation layer by N_2O plasma oxidation for Ge NMOSFETs application

In this paper, oxidation of Ge surface by N2O plasma is presented and experimentally demonstrated. Results show that 1.0-nm GeO2 is achieved after 120-s N20 plasma oxidation at 300 ℃. The GeO2/Ge interface is atomically smooth. The interface state density of Ge surface after N20 plasma passivation is about - 3 × 1011 cm-2.eV-1. With GeO2 passivation, the hysteresis of metal-oxide-semiconductor （MOS） capacitor with A1203 serving as gate dielectric is reduced to - 50 mV, compared with - 130 mV of the untreated one. The Fermi-level at GeO2/Ge interface is unpinned, and the surface potential is effectively modulated by the gate voltage.

Improved performance of AlGaN/GaN HEMT by N_2O plasma pre-treatment

The influence of an N2O plasma pre-treatment technique on characteristics of AlGaN/GaN high electron mobility transistor（HEMT） prepared by using a plasma-enhanced chemical vapor deposition（PECVD） system is presented.After the plasma treatment,the peak transconductance（gm） increases from 209 mS/mm to 293 mS/mm.Moreover,it is observed that the reverse gate leakage current is lowered by one order of magnitude and the drain current dispersion is improved in the plasma-treated device.From the analysis of frequency-dependent conductance,it can be seen that the trap state density（DT） and time constant（τT） of the N20-treated device are smaller than those of a non-treated device.The results indicate that the N2O plasma pre-pretreatment before the gate metal deposition could be a promising approach to enhancing the performance of the device.

CF4和O2等离子体刻蚀改善氮化硅薄膜形貌研究

探讨PA工艺因介电层高低差发生金属线路内部断裂的改善方案。以不同光刻条件和刻蚀条件为基础,对介电层(Si3N4)进行ICP刻蚀。研究表明,增加曝光焦距,刻蚀完的侧壁倾斜角改变不大;而光刻胶对氮化硅的刻蚀选择比越高,刻蚀完氮化硅侧壁斜角变化越大。当光刻胶对氮化硅的刻蚀选择比为2.4时,刻蚀完氮化硅的侧壁斜角可控制在45°~65°。

Laser Remelting of Plasma Sprayed NiCrAlY and NiCrAlY-Al_2O_3 Coatings

Two types of plasma sprayed coatings (NiCrAlY and NiCrAlY-A12O3) were remelted by a 5 kW cw CO2 laser. With increasing laser power and decreasing traverse speed in the ranges of 200-700 W and 5-30 mm/s respectively, the melted track grew in width and depth. In the optimum range of laser parameters, a homogeneous remelted layer without voids, cavities, unmelted particles and microcracks was formed. On the surface of remelted layers, Al203 and YAIO3 were detected. As a result of isothermal oxidation tests, weight gains of laser remelted coatings were obviously lower than that only plasma sprayed, especially laser remelted NiCrAlY-Al2O3 coatings. The effects of laser remelting and incorporation of A12O3 second phase in N1CrAlY matrix on high temperature oxidation resistance were discussed.

等离子体促进CH4-O2-N2-H2O体系转化试验研究

为提升瓦斯抽采利用率、促进煤矿安全生产,采用介质阻挡放电(DBD)试验系统对CH4-O2-N2-H2O反应体系进行低温等离子体转化研究,分析水蒸气与CH4物质的量比、O2/N2物质的量比、放电电压、放电频率,以及气体总流量对CH4转化率及主要产物产率的影响。结果表明:CH4-O2-N2-H2O反应体系DBD的主要产物为H2、CO、CO2、C2H2、C2H4、C2H6和CH3OH;反应参数对CH4转化率和H2、CO、CO2、C2H6、CH3OH产率影响较为显著,而对C2H2、C2H4产率影响不显著;CH4转化率及主要产物产率均在放电频率为9.8 k Hz时取得最大值。

Measurement of the O_2 Dissociation Fraction in RF Low Pressure O_2/Ar Plasma Using Optical Emission Spectrometry

Measurement of the oxygen dissociation fraction in RF low pressure oxygen/argon plasma using optical emission spectrometry is presented. The oxygen dissociation fraction and its evolutions as functions of operational parameters were determined using argon as the actinometer. At a pressure of 30 Pa, the oxygen dissociation fraction decreased from 13.4% to 9.5% as the input power increased from 10 W to 70 W. At an input power of 50 W, the oxygen dissociation fraction decreased from 12.3% to 7.7% when the gas pressure increased from 10 Pa to 40 Pa. The influences of operational parameters on the generation of atomic oxygen were also discussed.

Feature of Polysilane (UV Light Sensitive Materials)Treated by O_2-plasma

From the analysis of infrared (IR) transmission spectrum, it was showed that the SiO x films were produced when polymethyl phenethyl silane (PMPES) was treated with O 2 plasma, where the x ranged from 1.5 to 2. This film has a positive flat band voltage on the curve of high frequency C V chart, its value is dependent on the condition of O 2 plasma treatment and the thickness of PMPES film.

Effect of O_2/CH_4ratio on the optimal specific-energy-input (SEI) for oxidative reforming of biogas in a plasma-shade reactor

In a novel plasma-shade reactor for oxidative reforming of biogas(CH4/CO2=3/2),the effects of specific-energy-input (SEI) on CH4 and CO2 conversions and energy cost of syngas were investigated at O2/CH4ratios ranged from 0.42 to 0.67.At each of O2/CH4 ratios,V-shape profiles of energy cost of syngas increasing with SEI were observed,reaching the lowest value at the optimal SEI(Opt-SEI).With the increase of O2/CH4 ratio,the Opt-SEI decreased significantly.Moreover,at the Opt-SEI,O2 and CH4 conversions and dry-basis concentration of syngas increased and energy cost of syngas decreased greatly with the increase of O2/CH4 ratio.

The Effect of Discharge Power on the Atmospheric Pressure Non-equilibrium Ar/O_2/TiCl_4 Plasma Deposition of TiO_2 Film

Deposition of TiO2 film from atmospheric pressure non- equilibrium Ar/O2/TiCl4 plasma was done to study the effect of discharge power during the film deposition process in this paper. TiO2 films with kinds of morphologies and controlled crystallization were deposited from mixtures of TiCl4 and O2 on quartz substrate by one step process. Scanning electron microscope （SEM） and transmission electron microscope （TEM） were used to analyze the morphology and crystallization of the deposited TiO2 films. It was found that the discharge power played a key role in the morphology and crystallization of the deposited TiO2 film whether the flow of TiCl4was large or small. When the flow of TiCl4 was large, the deposited TiO2 film was amorphous particles at low discharge power and was multi-crystalline at high discharge power. When the flow of TiCl4 was small, the deposited TiO2 film became more compact and the crystallization was enhanced as the discharge power increased. The dependence of the discharge current and the applied voltage with the discharge power indicated that it was a glow discharge. The gas temperature which increases with the discharge power is one of the main causes that affect the morphology and crystallization of the deposited film.

热ALD和等离子增强ALD沉积HfO2薄膜的比较（英文）

以四(甲乙胺)铪(TEMAHf)作为前驱体,采用热原子层沉积(TALD)技术和等离子体增强原子层沉积(PEALD)技术分别在硅衬底上沉积二氧化铪(HfO2)薄膜。分别研究了水和臭氧作为共反应物对TALD HfO2薄膜性能的影响及采用电容耦合等离子体(CCP)PEALD HfO2薄膜的最佳工艺条件。通过X射线衍射(XRD)、扫描电子显微镜(SEM)和光电子能谱(XPS)对不同工艺制备的HfO2薄膜的微观结构、表面形貌进行了表征。结果表明,反应温度为300℃时,TALD 50 nm厚的HfO2薄膜为单斜相晶体;PEALD在较低反应温度(150℃)下充分反应,所沉积的50 nm厚的HfO2薄膜杂质含量较低,薄膜未形成结晶态;PEALD工艺得到的HfO2薄膜的界面层最厚,主要为硅的亚氧化物或铪硅酸盐。电流-电压(I-V)和电容-电压(C-V)测试结果表明,以水作为氧源且反应温度300℃的TALD工艺所得到的HfO2薄膜,其金属-绝缘体-半导体(MIS)器件的漏电流及电滞回线最小。

氧气等离子体处理提升InZnO材料及TFT电学性能和稳定性研究

氧化物薄膜晶体管(TFT)是有源矩阵有机发光二极管的核心驱动元件,是现今开发新型显示器的关键技术,在平板显示方面具有广阔的应用前景。但氧化物半导体中存在大量由氧空位引起的缺陷态,从而影响了TFT器件的性能及稳定性,成为其商业化进程的瓶颈。本文通过磁控溅射方法制备了IZO TFT,并将其进行O2等离子体处理,研究了离子体处理对IZO薄膜及TFT性能的影响。结果表明:O2等离子体处理后IZO TFT迁移率由8.2cm^(2)/(V·s)提高到9.5cm^(2)/(V·s),阈值电压由-3.2V减小到-5.1V,亚阈值摆幅由0.45V/decade减小到0.38V/decade,开关比由2.3×10^(7)提高到4.4×10^(7);在光照负偏压下,器件的阈值电压漂移量从7.1V降低到3.2V;在100℃老化条件下,器件的阈值电压漂移量从12.5V降低到6.4V;O2等离子体处理可以有效提高IZO TFT的电学性能和稳定性。

用氧等离子体处理改善竹地板胶合性能

为了解氧等离子体处理对竹材表面性能的影响,用表面润湿角测定评估竹材表面润湿性,通过测试竹地板的胶层剪切强度了解竹材胶合性能的变化。结果表明:竹材经过氧等离子体处理后,表面润湿角有较大减小,尤其是带有竹青和竹黄的竹片,润湿角从原来的76.5°降到36.0°,同时胶合强度提高33%。更重要的是竹地板的胶合强度变异系数从原来的39.0%降到9.8%,对于无竹青和竹黄的竹地板尽管胶合强度没有明显增加,但变异系数有显著的降低。因此,竹材经氧等离子体处理后,表面特性改善,压制的竹地板质量稳定性提高。

聚羟基烷酸酯薄膜的亲水性改性

分别采用氧等离子体方法和碱性条件下水解的方法对新型生物高分子3-羟基丁酸和3-羟基戊酸共聚物(PHBV)薄膜进行改性处理,以改善其亲水性和细胞亲和性。采用XPS考察了改性前后薄膜表面的组成、元素化学状态,用SEM观察了表面形貌变化,并考察了犬骨髓基质细胞在其上的生长情况。结果表明,经等离子体和水解改性后PHBV薄膜表面的氧含量分别增加了5．3％和2．5％,水接触角分别减小了36°和 16．7°,表明材料表面的亲水性增强。在氧等离子体处理后分别有1．5％和3．5％的C-O和C-C发生断裂, 生成亲水的羧基,而在碱性溶液中则发生酯键的水解。改性后的PHBV薄膜更有利于细胞的生长,尤以采用氧等离子体处理的效果更为明显。研究结果为进一步的表面改性修饰以及制备细胞亲和性好的PHBV三维支架打下良好基础。