基片偏压与氩分压对铀表面铝镀层结构与界面特性的影响

采用磁控溅射离子镀技术在贫铀表面以不同基片偏压与不同氩分压制备铝镀层,利用扫描电镜分析了镀层的表面和界面形貌,利用俄歇电子能谱仪分析了界面元素分布,利用透射电镜分析了镀层的微观结构.结果表明:钠表面脉冲偏压所得锚镀层较直流偏压所得镀层致密,脉冲偏压在-500～-1000V范围内镀层的致密性较好.铀表面脉冲偏压铝镀层与铀基体之间界面结合紧密,且存在"伪扩散层";随着脉冲偏压的提高,"伪扩散层"增宽.铝镀层为柱状结构,降低工作氩分压,可以细化铝镀层的晶粒,提高镀层的致密性.     

脉冲偏压对304不锈钢表面多弧离子镀CrAlN薄膜结构和耐蚀性能的影响

目前,鲜见有关脉冲偏压对多弧离子镀Cr Al N薄膜耐蚀性能影响的报道。以不同的脉冲偏压在304不锈钢表面多弧离子镀Cr Al N薄膜。采用扫描电镜、显微镜、X射线衍射仪、硬度仪、粗糙度仪分析了Cr Al N薄膜的表面形貌、相结构、硬度、表面粗糙度及耐蚀性能,分析了脉冲偏压对相关性能的影响。结果表明:随着脉冲偏压幅值的增大,Cr Al N薄膜表面大颗粒及凹坑尺寸和数量减少,薄膜质量提高;Cr Al N薄膜主要由(Cr,Al)N相组成,随着偏压增加,Cr Al N薄膜出现(220)择优取向;Cr Al N薄膜表面粗糙度随脉冲偏压增大而减小,显微硬度随脉冲偏压的增大而增大;Cr Al N薄膜在3.5%Na Cl溶液中的耐蚀性随着脉冲偏压的增大而增大,脉冲偏压为400 V时,Cr Al N薄膜与基体304不锈钢的腐蚀速率之比为0.34,薄膜的综合性能最好。     

脉冲偏压对磁过滤阴极电弧离子镀ta-C薄膜性能的影响

在不同脉冲偏压值下采用90°弯管磁过滤阴极电弧离子镀于硅片表面制备四面体非晶碳膜(Ta-C),研究了脉冲偏压对薄膜硬度、沉积速率、表面形貌及键价结构的影响。结论表明,薄膜沉积速率随脉冲偏压值的增加呈先增后减趋势,偏压值与膜层硬度值呈负相关性,高的偏压会抑制膜层中sp3键的形成,还能在一定程度上抑制大颗粒形成。本文研究内容为工业应用中通过脉冲偏压调整优化膜层综合性能提供参考。     

偏压方式对金刚石薄膜生长的影响研究

采用脉冲偏压和直流偏压辅助热丝化学气相沉积装置在硅片表面制备了金刚石薄膜,对比研究了两种方式施加的偏压大小对薄膜表面形貌以及质量的影响.利用扫描电子显微镜和拉曼光谱分别表征了薄膜的形貌和质量,采用等离子体光谱诊断分析了薄膜生长过程的气相化学反应.结果表明:两种偏压方式下偏压的大小对薄膜的形貌及品质均有较大影响.相比直流...     

脉冲偏压作用下MgO薄膜表面的荷电效应

采用脉冲偏压电弧离子沉积技术在玻璃基片上制备了透明的、具有择优取向的MgO薄膜。针对绝缘性薄膜表面的荷电效应,比较了脉冲偏压作用下鞘层对离子的加速时间(即鞘层的寿命)与脉冲宽度的大小以及偏压鞘层的初始厚度与离子穿越的距离的大小,讨论了不同占空比下偏压鞘层对离子的加速效应。利用X射线衍射及扫描电子显微镜对样品的观察结果表明,由于荷电效应,脉冲偏压幅值为-150 V,占空比在10%~40%的范围内,占空比的变化并不能改变MgO薄膜的微观结构和表面形貌。     

脉冲偏压对低温氮化不锈钢表面结构及摩擦学性能的影响

采用低温等离子体辅助氮化奥氏体不锈钢316L,能够在不破坏其抗腐蚀性能的同时有效提高不锈钢表面的摩擦学性能,研究了不同脉冲偏压下氮化层的结构和摩擦学性能(硬度、摩擦系数和耐磨性)。采用X射线衍射仪研究了脉冲偏压对氮化层相结构的影响;采用光学显微镜和扫描电镜分别观察了氮化层表面和横截面的形貌,并利用能量色散谱测量了氮化层中氮含量及其分布;基于纳米压痕和摩擦磨损结果,研究了脉冲偏压对氮化层摩擦学性能的影响。结果表明:低温氮化后,不锈钢表面形成一层无氮化物析出的单一过饱和固溶体相——扩展奥氏体γN,晶格常数随偏压的增加由0.359增至0.395nm。当脉冲偏压为-300 V时,氮化层厚度达9.45μm,表面硬度达21.0 GPa,摩擦系数降低至0.09,耐磨性能获得显著提高。     

Influence of Pulsed Bias Voltage on Surface Properties of TiN Thin Films Deposited by Arc Ion Plating with Big Rectangle Shaped Targets

采用矩形平面大弧源离子镀技术在201奥氏体不锈钢基体表面制备TiN硬质薄膜, 研究了脉冲偏压对TiN膜层的表面形貌、相结构、硬度和耐磨性能的影响. 结果表明, 随着脉冲偏压的增大, 薄膜中大颗粒的数目先增加后减少, 这是大颗粒受到离子拖曳力和电场力双重作用的结果. 存在一个最佳的脉冲偏压, 使得制备出的TiN膜层具有较高的I(111)/I(200)比例和较高的耐磨性. 脉冲偏压为-300 V时制备的TiN膜层具有最好的综合性能.     

脉冲偏压对矩形平面大弧源离子镀TiN 膜层性能的影响

采用矩形平面大弧源离子镀技术在201奥氏体不锈钢基体表面制备TiN硬质薄膜,研究了脉冲偏压对TiN膜层的表面形貌、相结构、硬度和耐磨性能的影响.结果表明,随着脉冲偏压的增大,薄膜中大颗粒的数目先增加后减少,这是大颗粒受到离子拖曳力和电场力双重作用的结果.存在一个最佳的脉冲偏压,使得制备出的TiN膜层具有较高的I(111)/I(200)比例和较高的耐磨性.脉冲偏压为-300 V时制备的TiN膜层具有最好的综合性能.     

不同温度下氮化铬薄膜的疏水性能研究

利用电弧离子镀膜技术,以硅片、不锈钢、玻璃片为基底,在脉冲偏压分别为50 V、100 V、150 V的条件下制备了三组氮化铬薄膜样品,对其物相、表面形貌、力学性能及不同温度下的疏水性能进行了分析研究。结果表明：所制备薄膜样品组分单一,表面存在些许“大颗粒”,当脉冲偏压为100 V时“大颗粒”数量最多;氮化铬薄膜力学性能优良,150 V脉冲偏压下沉积的薄膜具有较高的硬度和杨氏模量,50 V脉冲偏压样品具有较高的膜基结合力;常温（20℃）下薄膜疏水性均较好,基底材料对疏水性能影响不大;各组薄膜疏水性能随环境温度的增加而降低,当环境温度上升至80℃时脉冲偏压为50 V的薄膜丧失疏水性能,脉冲偏压为100 V的薄膜样品疏水性能整体较优。     

基体放置状态与脉冲偏压幅值对大颗粒形貌和分布的影响

利用电弧离子镀方法制备了TiN薄膜,研究了脉冲偏压幅值和试样放置状态对Ti大颗粒形貌和分布规律的影响。采用扫描电子显微镜观察了薄膜的表面形貌,利用Image J科学图像软件对Ti大颗粒的数目和尺寸进行了分析。结果表明:在不施加脉冲偏压时,随着试样表面与靶表面放置方向从平行到垂直,大颗粒数目迅速由4964降低到3032,所占薄膜的面积比从12.1%减少到4.7%;而在相同的放置方向下,发现静止状态下的薄膜表面大颗粒数目较少,尺寸也较小,而转动状态下大颗粒形貌差别较大,尺寸和所占的面积比较大。随着脉冲偏压幅值的增加,在各个放置状态下大颗粒都出现了先减小后增加的趋势,当幅值在-400 V时,薄膜表面大颗粒所占的面积比都达到最小值。     

Experimental Verification of the Physical Model for Droplet-Particles Cleaning in Pulsed Bias Arc Ion Plating

It has been reported that application of pulsed biases in arc ion plating could effectively eliminate droplet particles. The present paper aims at experimental verification of a physical model proposed previously by us which is based on particle charging and repulsion in the pulsed plasma sheath. An orthogonal experiment was designed for this purpose, using the electrical parameters of the pulsed bias for the deposition of TiN films on stainless steel substrates. The effect of these parameters on the amount and the size distribution of the particles were analyzed, and the results provided sufficient evidence for the physical model.     

Plasma enhanced chemical vapor deposition of a-C:H films in CH4-CO2 plasma: Gas composition and substrate biasing effects on the film structure and growth process

Diamond-like quality films have been deposited by low pressure Radio Frequency-Plasma Enhanced Chemical Vapor Deposition using the non-conventional CH₄-CO₂ mixture as gas precursor, associated with an innovative bipolar pulsed biasing technology. A comprehensive study was performed in search for the best precursors composition and process parameters together with a detailed chemical, structural and mechanical characterization of the films. We gained experimental evidences on the key role performed by a bipolar pulsed bias in creating more energetic conditions in the plasma, allowing obtaining at lower voltages material properties comparable to or even better than those achieved with higher biases but applied in the traditional continuous mode. This is achieved especially when combining such a biasing technology with plasmas containing oxygen bearing species, which provide both positively and negatively charged ions in the gas phase.     

A Study of AlN Films Prepared by Arc Ion Plating

Hexagonal AlN films have been obtained by arc ion plating at different negative biases ,X-ray diffraction and scanning electron microscopy results show that AlN films with smooth surfaces and (002) preferred orientation are obtained at low biases ,whereas those with coarse surfaces and (100) preferred orientation are obtained at high biases,The formation mechanism of AlN is analyzed and the experiment results are discussed,The effect of bias on adhesion strength has also been examined.     

Effect of bias voltage on microstructure and mechanical properties of nanocrystalline TiN films deposited by reactive magnetron sputtering

Nanocrystalline TiN films deposited under various bias voltages have been prepared by a reactive magnetron sputtering. The effect of bias voltage on the microstructural morphologies of the TiN films was characterized by FE-SEM and AFM. The texture of the TiN films was characterized by XRD. It is also observed that the crystallite size decreases with increasing bias voltages. However, rms roughness increases with increasing bias voltages. The changes in roughness and crystallite size in the TiN thin films are due to one or a combination of factors such as resputtering, ion bombardment, surface diffusivity and adatom mobility; the influence of each factor depends on the processing conditions.     

The influence of deposition rate on the stress and microstructure of AlN films deposited from a filtered cathodic vacuum arc

Aluminium nitride (AlN) thin films have been reactively deposited using a filtered cathodic vacuum arc system. A pulsed substrate bias was applied in order to increase the average energy of the depositing species. The stress and microstructure of the films were determined as a function of the deposition rate and pulse bias amplitude/frequency. The stress generated in films grown with high voltage pulsed bias depended on the deposition rate and a transition from tensile stress to compressive stress occurred as the deposition rate increased. This trend was accompanied by progressive changes in the microstructure. In order of increasing deposition rate, the films exhibited: a porous structure with tensile stress; a dense AlN film with compressive stress; and a dense AlN film showing evidence of a thermally induced reduction in stress.     

Properties of zirconium oxide films prepared by filtered cathodic vacuum arc deposition and pulsed DC substrate bias

Thin films of zirconium dioxide have been deposited onto glass and silicon substrates using filtered cathodic vacuum arc deposition under a pulsed negative DC bias. The properties of the films have been investigated using X-ray diffraction, X-ray photoelectron spectroscopy, microhardness testing and optical analysis. It was found that the crystalline phase of the films was strongly influenced by the applied bias and that an amorphous-monoclinic transition occurred on glass substrates for bias values > 250 V. The changes in crystallinity also resulted in an increase in the optical refractive index from 2.09 to 2.22 at 550 nm. A similar behaviour in the variation of the microhardness with applied pulsed DC bias was also observed, where the hardness increased from 11 GPa to 16. 5 GPa.     

Process parameters optimization for laser deposition of highT c superconducting thin films on Si and other substrate materials

Thin films of Y-Ba-Cu-O superconductor have been deposited on different substrates by pulsed excimer laser ablation from a superconducting pellet. The dependence of various process parameters such as substrate temperature, laser energy density, oxygen partial pressure, applied bias field and cooling rates on the quality of the films has been studied.     

脉冲偏压对等离子体沉积DLC膜化学结构的影响

以乙炔为气源，用等离子体基脉冲偏压沉积（plasma based pulsd bias deposition缩写PBPBD）技术进行了不同负脉冲偏压条件下制备DLC膜的试验，通过X射线光电子谱（XPS）、激光喇曼光谱[Raman]以及电阻分析方法考察了负脉冲偏压幅值对DLC膜化学结构的影响，结果表明由-50kV到-10kV随负脉冲偏压降低，DLC膜中SP^3键分数单调增加，但当脉冲偏压为0时形成高电阻的类聚合物膜，说明荷能离子的轰击作用形成DLC化学结构的必要条件，键角混乱度和SP^2簇团尺寸与脉冲偏压之间不具有单调关系，在中等幅值负脉冲偏压条件下，键用混乱度较大且SP^2簇团尺寸细小。     

The effects of pulse frequency and substrate bias to the mechanical properties of CrN coatings deposited by pulsed DC magnetron sputtering

The chromium nitride coatings have been prepared by the bipolar symmetric pulsed DC magnetron reactive sputtering process at 2 kHz and 20 kHz pulse frequencies, respectively. Different substrate bias was applied with a pulsed DC bias unit with 50 kHz pulse frequency. Oscilloscope traces of the I–V waveforms indicate high power and high current density outputs during the symmetric bipolar pulsed mode. It is concluded that the (200) orientation of CrN films is observed. The grain size decreases with increasing pulse frequency and substrate bias. The substrate bias has a strong influence on the mechanical properties of CrN films. The scratch tests of the CrN coatings show that almost only tiny chipping failure is occurred. Sufficient adhesion strength quality of the coating is also observed. The substrate bias for the deposition of CrN films with sufficient hardness and adhesion properties combination is − 290 V at 20 kHz and − 408 V at 2 kHz pulse frequency, respectively.