递进式脉冲激光沉积CN_x薄膜的组织结构与摩擦学特性

采用脉冲激光沉积法(PLD)在不同激光通量下烧蚀CNx靶,在单晶硅基底上沉积CNx薄膜。利用扫描电子显微镜(SEM)、X射线能谱仪(EDS)、X射线光电子谱仪(XPS)等对薄膜的形貌、化学成分和微观结构进行了表征。采用球-盘式磨损试验机在大气(相对湿度48%～54%)环境下测试了薄膜的摩擦学特性。结果表明,递进式PLD技术可显著提高CNx薄膜的含氮量。当激光通量从5.0J/cm2提高至10.0J/cm2时,薄膜含氮原子数分数由23.8%上升至29.9%,膜中N-sp2 C键的含量上升,N-sp3 C键和sp3 C-C键的含量下降,薄膜的磨损率从2.1×10-15 m3/(N.m)上升至9.0×10-15 m3/(N.m)。摩擦系数为0.15～0.23,激光通量5.0J/cm2沉积的薄膜有最佳摩擦学性能。     

多靶共焦磁控溅射设备及工艺应用研究

本文介绍了一种用于磷化铟（InP）器件金属剥离工艺的多靶共焦式磁控溅射设备。通过正交实验摸索不同靶基距、靶角度对薄膜均匀性的影响,在靶基距为110～140mm,靶角度处于20。～25。之间时薄膜均匀性优于5%。取最优薄膜均匀性的靶基距、靶角度,实验摸索了不同溅射气压下薄膜的台阶覆盖率,结果表明在一定溅射气压范围内,薄膜台阶覆盖率随溅射气压减小而增加。取最优薄膜均匀性的靶基距、靶角度及最优台阶覆盖率的溅射气压,实验摸索了不同溅射功率下基片的表面温度,结果表明在常用光刻胶耐温范围内,较优的溅射功率为300W～400W。     

低真空下射频磁控溅射法制备ITO薄膜

在低真空(2.3×10-3 Pa)下采用射频磁控溅射法制备了ITO薄膜.溅射温度200 ℃,溅射气氛为氩气和氧气的混合气,溅射靶材为90 %氧化铟、10 %氧化锡的陶瓷靶.用场发射扫描电子显微镜和X衍射仪研究了薄膜的显微结构, 用X射线光电子能谱表征了薄膜的成分.ITO薄膜在可见光范围内有较高的透射率(80 %～95 %).在低工作气压(1 Pa)下,氧气流量比率[O2/(O2+Ar)]越小,薄膜的透射率越高、导电性越好.在高工作气压(2 Pa)下,制备得到低质量、低透射率的无定形薄膜.     

溅射气氛对VOx薄膜结构及性能的影响

溅射总气压一定,通过改变氧氩气体的比例,用射频磁控反应溅射法在玻璃衬底上制备VOx薄膜.用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、QJ31单臂电桥等测试了不同氧氩比例对VOx薄膜的晶体结构、表面形貌、成分和电阻的影响.测试分析结果表明,氧氩比是影响VOx薄膜结构及性能的重要因素.在我们的实验条件下,最佳氧氩比为2∶25,电阻温度系数为-2.87%/℃.     

溅射工艺参数对BST薄膜介电常数的影响

采用射频磁控溅射法在ITO玻璃基片上制备了约700nm的Ba0.5Sr0.5Ti03(BST)薄膜。研究了溅射功率、气压、ψ[O2/(Ar+O2)]比和基片温度对εr的影响,获得各种溅射条件下的薄膜的εr为250~310。提出了较优的工艺,即本底真空1.5×10–3Pa、靶基距6.2cm、功率300W、气压1.8Pa、ψ[O2/(Ar+O2)]为30%和衬底温度500℃,并研究了薄膜的晶相、组成和形貌。     

靶基距对反应溅射AlN薄膜微结构和性能的影响

采用射频(RF)磁控反应溅射法在Si基底上制备了氮化铝(AlN)薄膜,利用X射线衍射(XRD)、傅立叶红外光谱(FTIR)、扫描电子显微镜(SEM)和纳米力学测试系统研究靶基距对AlN薄膜取向性、微结构、形貌和力学性能的影响。结果表明,靶基距较大时,形成的AlN薄膜为非晶态,薄膜表面较疏松;随着靶基距的减少,AlN薄膜变为多晶态,且具有(100)择优取向;随着靶基距的进一步减少,薄膜结晶质量变好,晶粒变大,薄膜变得更致密,择优取向也由(100)逐渐向(002)转变;靶基距较小时,AlN压电薄膜与基底结合得更牢固,而压电薄膜与基底结合的紧密程度对多层膜声表面波(SAW)器件性能优劣的影响至关重要。     

磁控溅射工艺参数对Cu薄膜电阻率的影响

在确定Cu薄膜临界尺寸的基础上,选定基底温度、靶基距、溅射功率和工作气压为影响因素设计正交试验,研究了磁控溅射制备工艺对Cu薄膜电阻率的影响。研究结果表明:基底温度是影响薄膜电阻率的最主要因素,电阻率随着基底温度的升高而减小;在工艺条件为基底温度200℃、靶基距45 mm、溅射功率100 W、工作气压0.5 Pa时,所制薄膜的电阻率将会达到最小。最后,结合薄膜微观形貌对试验结论进行了分析,并对最佳工艺条件进行了实验验证。     

铜薄膜的直流磁控溅射制备与表征

根据薄膜的形成机理,用直流磁控溅射方法制备出了表面结构平滑、致密的Cu薄膜.实验中,采用纯度＞99.9%的铜靶,工作气压保持在2.7 Pa不变,玻璃衬底温度随环境温度变化.用X射线衍射仪(XRD)、扫描电镜(SEM)研究了薄膜的织构、晶粒尺寸和表面形貌.结果表明,随着溅射功率增大,薄膜织构减弱;溅射功率增大和溅射时间增加均可使薄膜的晶粒尺寸增大,在溅射功率≤100 W时获得的薄膜晶粒细小,有裂纹缺陷;溅射功率为150 W,溅射时间为30 min时,薄膜表面结构平滑、致密,晶粒尺寸相对较大.须进一步改进工艺参数,如衬底温度等,从而制备出表面结构平滑、致密、晶粒细小的薄膜.     

氮氩体积流量比对AlN薄膜生长取向、晶体质量及沉积速率的影响及机理分析

采用反应磁控溅射法,在溅射气压、溅射功率和衬底温度恒定的条件下,通过调控氮氩体积流量比,在单晶Si衬底上制备AlN薄膜。利用X射线衍射仪(XRD)、原子力显微镜(AFM)和场发射扫描电子显微镜(FESEM)研究氮氩体积流量比对AlN薄膜的生长取向、晶体质量及沉积速率的影响规律并分析其机理。结果显示,提高氮氩体积流量比有利于AlN薄膜(002)择优取向的生长,但过高的氮氩体积流量比会降低薄膜的沉积速率。在溅射气压为5 mTorr(1 Torr=133.3 Pa)、溅射功率为500 W、衬底温度为200℃、氮氩体积流量(cm³/min)比为14∶6时,在单晶Si衬底上可以制备出质量较好的,具有良好(002)择优取向的AlN薄膜。研究结果可为反应磁控溅射制备高质量AlN薄膜提供工艺参数设置规律指导。     

金刚石/硅复合膜的导热特性研究

用金刚石粉,用不同时间在两片镜面抛光的(111)硅基片上分别打磨.两片硅基片打磨后都仍保持镜面特征.采用微波等离子体化学气相沉积系统,利用氢气、甲烷和氧气为前驱气体,在同样参数条件下,在基片上制备了直径5 cm的金刚石薄膜.用扫描电镜和X射线衍射分析两片薄膜结构.分析结果表明其表面形貌基本相同都为(111)择优取向的金刚石薄膜;但X射线衍射分析表明打磨时间较长的薄膜中含有一定量在非晶成分.用热导测试仪测试两薄膜和硅基片的热导率约为:241.7 W/mK,192.9 W/mK和169.3 W/mK.结合扫描电镜和X射线衍射分析结果我们讨论了基底处理对金刚石/硅复合膜的导热特性的影响.     

Characterization of sputtered tungsten nitride film and its application to Cu electroless plating

In this study, W and tungsten nitride films were fabricated by reactive sputtering in a N₂/Ar atmosphere, the native oxide growth on the surface of the tungsten nitride films was investigated by X-ray photoelectron spectroscopy (XPS). It was found that tungsten nitride films were the mixture of W and W₂N sputtered in atmospheres of 3 mTorr argon and at the N₂ partial pressure from 0.1 to 2.0 mTorr. The ratio of W and W₂N in films was changed with the nitrogen partial pressure in sputtered chamber. Surface oxidations of the W film and tungsten nitride films advanced with time. Electrochemical measurement shows that all reduction-oxidation (redox) potentials of tungsten and tungsten nitrides were lower than that of copper film in electroless copper solution. And so, electroless-plated copper could be deposited on the surface of tungsten nitride films when the substrates were immersed into electroless copper plating solution without any pretreatment. Tungsten nitride films are appropriate for ULSI Cu interconnections using electroless Cu deposition.     

磁控溅射氧化钛薄膜的电学特性研究

采用直流磁控溅射法在K9玻璃上制备了不同溅射温度和氧气流量的氧化钛(TiOx)薄膜.采用XPS、霍尔效应测试仪对薄膜的组份、载流子浓度和迁移率进行了测试,发现随着溅射氧气流量的增大,薄膜中的氧元素比例增大,载流子浓度减小,迁移率增大.分析了TiOx薄膜的电阻温度系数(TCR)与溅射温度和氧分压的关系,薄膜的电阻率从0....     

La_(0.6)Sr_(0.4)CoO_3薄膜的制备及NTC特性研究

为研制具有较低室温电阻值的NTC薄膜热敏电阻,以La0.6Sr0.4CoO3陶瓷为靶材,采用RF磁控溅射法,在Al2O3基片上沉积了La0.6Sr0.4CoO3(LSCO)薄膜。研究了溅射过程中氩氧体积流量比对LSCO薄膜结晶性能和方阻的影响以及LSCO薄膜的阻温特性。结果表明:随着氩氧体积流量比的增加,LSCO薄膜的主晶相衍射峰强度及方阻均先增大后减小。LSCO薄膜具有显著的NTC特性,室温时的电阻温度系数α25为2.24×10–5;其lnR-T–1曲线具备良好的线形度,线性偏差仅为2.09%;另外,其室温时的电阻R25仅为18.75k?。     

Composition of pulsed-laser-deposited Y-Ba-Cu-0 and Ba-K-Bi-O thin films

The composition of pulsed-laser-deposited Y-Ba-Cu-O and Ba-K-Bi-O thin films is shown to be strongly affected by target conditioning, gas pressure, and target-substrate distance. For both compounds, ablation from a freshly sanded target surface results in films with an excess of the more volatile elements. The concentration of these volatile elements in the films decreases until the system reaches a steady state after sufficient ablation from the target. Y-Ba-Cu-O film composition is also affected by oxygen pressure and target-substrate distance. Increasing pressure or distance results in relative copper and barium depletion in the central region of deposition, presumably due to differences in the efficacy of oxygen in scattering the different elements. This relationship between pressure, distance, and composition is shown to be significant for the growth of optimal superconducting Y-Ba-Cu-O thin films. The composition of Ba-K-Bi-O is also affected strongly by background gas pressure. Ba-K-Bi-O deposited in vacuum is potassium deficient in the film center. A background argon pressure of 1 Torr, however, increases the potassium concentration and results in films with uniform composition over a broad area. We argue that this effect is significant in explaining a successful growth method for superconducting Ba-K-Bi-O films.     

Synthesis and electromagnetic transport of large-area 2D WTe2 thin film

Tungsten telluride thin films were successfully prepared on monocrystal sapphire substrates by using atomic layer deposition and chemical vapor deposition technology, and the effects of different tellurization temperatures on the properties of tungsten telluride films were investigated. The growth rate, crystal structure and composition of the film samples were characterized and analyzed by using scanning electron microscope, Raman spectroscopy and X-ray photoelectron spectroscopy. The results showed that tungsten telluride thin films with good crystal orientation in (001) were obtained at telluride temperature of 550 °C. When the telluride temperature reached 570 °C, the tungsten telluride began to decompose and unsaturated magnetoresistance was found.     

氧压对ZnO薄膜电阻温度系数的影响

采用脉冲激光沉积(PLD)技术,在不同氧气氛下,在Si(lll)衬底上生长了ZnO薄膜,使用X线衍射仪分析了ZnO薄膜的结晶质量.计算了不同氧气氛下生长的ZnO薄膜的电阻温度系数(TCR)值,发现随着氧分压降低,ZnO薄膜的TCR值增大;ZnO薄膜的TCR值最高可达-8%/K.这为研究ZnO薄膜的导电特性提供了新的途径,开辟了ZnO薄膜在室温非制冷红外微测辐射热计材料中的应用潜力.     

Ultra-short pulsed laser deposition and patterning of SiC thin films for MEMS fabrication

A Ti:Sapphire (IR 800-nm) femtosecond (fs) pulsed laser was used to ablate a sputtering grade of silicon carbide (SiC) in an ultra-high vacuum chamber. The laser-induced plasma species were then driven and grown to form 3C-SiC films of about 1 μm thick on single crystal silicon wafers at 20 °C (room temperature) and 500 °C. Scanning electron microscopy, atomic force microscopy, X-ray photoelectron microscopy, X-ray diffraction and nanoindentation were used to characterize the structure, composition, thickness and properties of the SiC films. Results of the femtosecond-pulse laser deposited (fs-PLD) films were compared with those obtained by atmospheric pressure chemical vapor deposition (APCVD) and nanosecond-pulse laser (excimer laser at 248-nm) deposition (ns-PLD). The distinctive features of fs-PLD films are their extremely smooth surfaces, stoichiometry, amorphous structure and low defect density compared to APCVD films, along with better film quality and higher growth rates than ns-PLD films. In addition to film growth studies, a SiC microgripper (to grab 20-μm-sized objects) was micromachined by use of the fs-pulsed laser to demonstrate the utility of ultra-short PLD in SiC-device fabrication.     

脉冲激光沉积法沉积类金刚石薄膜的实验研究

为了研究脉冲激光沉积法中衬底温度和距离对类金刚石薄膜的影响,首先温度保持在200℃,靶和衬底间的距离分别取25.0mm和30.0mm来沉积类金刚石膜。其次温度保持在400℃,距离分别取25.0mm和30.0mm来沉积类金刚石膜。用Raman光谱仪对薄膜的微观结构进行检测,用原子力显微镜对薄膜的表面形貌进行检测。实验结果表明：距离增加或者温度升高都会导致类金刚石薄膜的密度和sp3/ sp2的比值减小,薄膜中石墨晶粒的数量增多和体积增大。近距离时温度的变化和低温时距离的变化对薄膜微观结构产生的影响更明显。距离和温度的变化对类金刚石薄膜的表面形貌也产生显著的影响。     

Preparation of Vanadium Dioxide Films for Protection from High—energy Laser Hits

Vanadium dioxide(VO2) thin films are used for protection from high-energy laser hits due to their semiconductor-to-metal phase transition experienced during heating at temperature of approximately 68℃,which followed by a abrupt change of optical behavior,namely from transparent semiconductor state below 68℃ to highly reflective metallic state beyond 68℃.The preparation and properties of the films are described as well as the primary principle of the device for protection from high energy laser hits.An ion-beam-sputtering system is used to deposit VO2 thin films.The technique is reactive ion beam sputtering of vanadium at temperature of 200℃ on Si,Ge and Si3N4 substrates in a well controlled atmosphere of argon with a partial pressure of O2,followed by a post annealing at 400-550℃ with argon gas.The optical transmittance changes from 60% to 4% are obtained within the temperature range from 50℃ to 70℃ .X-ray diffraction(XRD) shows that the films are of single-phase VO2.