锰铜薄膜的制备及压阻特性

为了锰铜传感器微型化,采用直流磁控溅射法制备适合高压力测量的锰铜薄膜,用X射线衍射和扫描电子显微镜技术分析了薄膜的结构和形貌,动态加载实验标定了锰铜薄膜的压阻系数。研究结果表明,晶粒尺寸决定了薄膜的压阻系数,经360℃热处理1h后,薄膜晶粒长大,压阻系数有着明显提高(K值达到0.02GPa–1),性能达到锰铜箔的水平。     

电沉积法制备ZnO薄膜的结构与光电性能研究

以硝酸锌和硝酸钾混和溶液为电解液,采用两电极体系在SnO2;F(FTO)片和p-Si(100)衬底上用不同沉积电压制备了c轴取向的ZnO薄膜.用X-射线衍射、扫描电子显微镜和分光光度计分析了薄膜的相结构,晶粒尺寸和光吸收特性.发现薄膜的(002)衍射峰强度随着沉积电压的增加而显著增强;薄膜中晶粒为典型的六方柱状结构,且基本与衬底垂直,晶粒尺寸为200～400 nm;薄膜的光学禁带宽度为3.34 eV.光照时,ZnO/Si异质结二极管呈明显的光生电流效应.     

前驱体通气时间对原子层沉积氧化锌薄膜的影响

建立了反应腔室模型,模拟分析了原子层沉积(ALD)过程中前驱体质量分数随其通气时间的变化趋势.采用ALD法制备了ZnO薄膜,采用原子力显微镜(AFM)与扫描电子显微镜(SEM)对薄膜进行了表征,研究了不同二乙基锌通气时间下ZnO薄膜的表面形貌和厚度均匀性.模拟结果表明,前驱体通气时间越长,前驱体在整个反应腔室内的分布越...     

基于ZnO压电薄膜的柔性MEMS超声波换能器

该文提出一种柔性的微机电系统(MEMS)超声波器件。该器件由下电极、ZnO薄膜、上电极及聚酰亚胺柔性基底构成。其制作过程简单,采用直流磁控溅射制作上、下电极,反应射频磁控溅射制作氧化锌压电薄膜。薄膜间粘合牢固,可反复弯折。SEM和XRD结果表明,氧化锌薄膜厚度可达4~8μm,具有高度(002)择优取向的柱状晶结构。根据XRD所得的结果计算了薄膜平均晶粒尺寸和内应力大小,结果表明,晶粒尺寸约为22nm,薄膜内压应力约为-1.248 4GPa。利用激光多普勒测得其共振频率约为5MHz。同时,研究发现,较厚的ZnO薄膜使振幅变大,导致振动品质因数(Q)值增加。     

掺铝ZnO透明导电薄膜的制备及光电性能研究

采用RF磁控溅射法制备了掺铝ZnO(AZO)透明导电薄膜,用X射线衍射仪、分光光度计和四探针仪等,研究了沉积温度对薄膜晶体结构和光电性能的影响。结果表明,AZO薄膜为六方纤锌矿结构的多晶膜,具有(002)择优取向。沉积温度对薄膜的择优取向程度、晶粒尺寸、透射率和导电性能等具有明显的影响。当沉积温度为400℃时,AZO薄膜最大晶粒尺寸为37.21nm、可见光范围平均透射率为85.5%、优良指数为1.30×10-2?-1。     

原子层沉积超薄氮化铝薄膜的椭圆偏振光谱法表征

采用原子层沉积(ALD)工艺在硅衬底上生长了35 nm以下不同厚度的超薄氮化铝(AlN)晶态薄膜。利用椭圆偏振光谱法在波长275~900 nm内测量并拟合薄膜的厚度及折射率和消光系数等光学参数。利用原子力显微镜(AFM)表征AlN晶粒尺寸随生长循环次数的变化,计算得到薄膜表面粗糙度并用于辅助椭偏模型拟合。针对ALD工艺特点建立合适的椭偏模型,可获得AlN超薄膜的生长速率为0.0535 nm/cycle,AlN超薄膜的折射率随着生长循环次数的增加而增大,并逐渐趋于稳定,薄膜厚度为6.88 nm时,其折射率为1.6535,薄膜厚度为33.01 nm时,其折射率为1.8731。该模型为超薄介质薄膜提供了稳定、可靠的椭圆偏振光谱法表征。     

衬底温度对射频磁控溅射制备氮化硅薄膜的影响

采用射频磁控反应溅射技术,以N2和Ar为反应气体在普通玻璃表面沉积了氮化硅(SiN)薄膜;利用X射线衍射仪、扫描电子显微镜、X射线能量耗散谱、台阶仪和紫外-可见光谱,研究了不同衬底温度对SiN薄膜的相结构、表面形貌和成分、薄膜厚度以及光性能的影响.结果表明;制备的SiN薄膜为富硅结构;提高衬底温度,可增加光学带隙;当衬底温度为450℃时,薄膜由尺寸约为40 nm的SiN晶粒组成,且在紫外-可见光区的透过率高达90%.     

基于铜铝氧化物的透红外导电薄膜

研究了一种新型透红外的导电薄膜铜铝氧化物(CuAlxOy),选用高纯度铜、铝靶材,利用磁控溅射台在蓝宝石衬底上生长CuAlxOy薄膜。研究了氧气流量、薄膜厚度、预溅射铜层时间(铜层厚度)等重要条件对薄膜性能的影响。实验发现,通过微调溅射参数、合理控制预溅射铜层过程可以获得低电阻率和高透过率的铜铝氧化物薄膜。得到最好的CuAlxOy薄膜(厚度为1765)在波长2.6μm处红外透过率达到了最大值62.5%,红外波段(波数8000～2000 cm-1)的平均透过率达到53%,方块电阻为358.9/sq,电阻率为6.33×10-3.cm。     

膜厚对ITO薄膜的电学与光学性质的影响

用射频磁控溅射法在玻璃衬底上制备不同薄膜厚度氧化铟锡(ITO)透明导电薄膜.利用X线衍射(XRD)、透射光谱、四探针法和扫描电子显微镜(SEM)分析薄膜厚度(沉积时间)对ITO薄膜的结晶取向情况、透过率、电导率和表面形貌的影响.试验结果表明,在适当的沉积时间(5 min)下制备的ITO薄膜具有良好的光学性能和电学性能,其方阻为17 Ω/□,在可见光区域内的平均透过率为84%.     

制备工艺条件对薄膜微结构的影响

用不同的方法在石英玻璃,YAG晶体,K9玻璃和LiNbO3晶体等几种衬底上制备了ZrO2,HfO2和TiO2薄膜。HfO2薄膜利用电子束蒸发(EB)、离子束辅助(IAD)和双束离子束溅射(DIBS)三种方法沉积。对其中的一些样品进行了不同温度下的退火处理,对所有的样品进行X射线衍射(XRD)测试,以获得不同条件下得到的薄膜的晶相及晶粒尺寸等的微结构参数。实验结果表明,薄膜的晶相结构以及晶粒尺寸强烈地依赖于沉积过程的各种技术参数,如衬底的种类、沉积温度、沉积方法和退火温度。利用薄膜表面扩散以及薄膜成核长大热力学原理解释了不同技术条件下的晶相结构和晶粒尺寸不同的原因。     

纳米压痕法分析Sn-9Zn/Cu焊点力学性能

通过对Sn-9Zn/Cu焊点进行纳米压痕实验发现:在保载阶段,体钎料产生了明显的蠕变特征,蠕变深度随着加载速率的增加而增加.基于压痕做功概念确定了Sn-9Zn/Cu焊点中体钎料的蠕变应力指数n约为5.128.硬度和弹性模量测试结果表明:金属间化合物Cu5Zn8的压痕硬度(5.152±0.224) GPa约是体钎料压痕硬...     

High rate (~7 nm/s), atmospheric pressure deposition of ZnO front electrode for Cu(In,Ga)Se2 thin‐film solar cells with efficiency beyond 15%

Undoped zinc oxide (ZnO) films have been grown on a moving glass substrate by plasma‐enhanced chemical vapor deposition at atmospheric pressure. High deposition rates of ~7 nm/s are achieved at low temperature (200 °C) for a substrate speed from 20 to 60 mm/min. ZnO films are highly transparent in the visible range (90%). By a short (~minute) post‐deposition exposure to near‐ultraviolet light, a very low resistivity value of 1.6·10⁻³ Ω cm for undoped ZnO is achieved, which is independent on the film thickness in the range from 180 to 1200 nm. The photo‐enhanced conductivity is stable in time at room temperature when ZnO is coated by an Al₂O₃ barrier film, deposited by the industrially scalable spatial atomic layer deposition technique. ZnO and Al₂O₃ films have been used as front electrode and barrier, respectively, in Cu(In,Ga)Se2 (CIGS) solar cells. An average efficiency of 15.4 ± 0.2% (15 cells) is obtained that is similar to the efficiency of CIGS reference cells in which sputtered ZnO:Al is used as electrode. Copyright © 2013 John Wiley & Sons, Ltd.     

Atomic layer chemical vapour deposition of copper

Copper films with (1 1 1) texture are of crucial importance in integrated circuit interconnects. We have deposited strongly (1 1 1)-textured thin films of copper by atomic layer deposition (ALD) using [2,2,6,6-tetramethyl-3,5-heptadionato] Cu(II), Cu(thd)₂, as the precursor. The dependence of the microstructure of the films on ALD conditions, such as the number of ALD cycles and the deposition temperature was studied by X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy. Analysis of (1 1 1)-textured films shows the presence of twin planes in the copper grains throughout the films. SEM shows a labyrinthine structure of highly connected, large grains developing as film thickness increases. This leads to low resistivity and suggests high resistance to electromigration.     

Study on ALD In2S3/Cu(In,Ga)Se2 interface formation

The formation of the interface between In₂S₃ grown by atomic layer deposition (ALD) and co‐evaporated Cu(In,Ga)Se₂ (CIGS) has been studied by X‐ray and UV photoelectron spectroscopy. The valence band offset at 160°C ALD substrate temperature was determined as −1·2±0·2 eV for CIGS deposited on soda‐lime glass substrates and −1·4±0·2 eV when a Na barrier substrate was used. Wavelength dependent complex refractive index of In₂S₃ grown directly on glass was determined from inversion of reflectance and transmittance spectra. From these data, an indirect optical bandgap of 2·08±0·05 eV was deduced, independent of film thickness, of substrate temperature and of Na content. CIGS solar cells with ALD In₂S₃ buffer layers were fabricated. Highest device efficiency of 12·1% was obtained at a substrate temperature of 120°C. Using the bandgap obtained for In₂S₃ on glass and a 1·15±0·05 eV bandgap determined for the bulk of the CIGS absorber, the conduction band offset at the buffer interface was estimated as −0·25±0·2 eV (−0·45±0·2 eV) for Na‐containing (Na‐free) CIGS. Copyright © 2005 John Wiley & Sons, Ltd.     

激光沉积红外窗口高性能类金刚石膜技术

类金刚石(DLC)膜具有宽光谱高透射率、高硬度、高热传导及高稳定性等优点,是红外窗口增透保护膜的优选,但现有方法制备的类金刚石膜难以满足高马赫数或海上盐雾等恶劣条件下的应用。激光法相比其他制备方法具有诸多优点,介绍了激光法制备DLC膜的原理及特点,并分析了实现工程应用的难题及关键技术。采用激光沉积法制备出综合性能优异的类金刚石膜,纳米硬度高达44 GPa、内应力仅0.8 GPa、临界刮擦载荷附着力为59.1 mN。正面镀DLC膜,背面镀普通增透膜的硫化锌、硅、锗等红外窗口的平均透射率达82%~91%。实现了150 mm基片的激光法大尺寸均匀薄膜,膜厚不均匀性≤±2%。制备的DLC膜红外窗口通过军标环境适应性试验,并已实现工程化应用。     

Fabrication and Characterization of Solar Cells Made of p-CuO/n-Si Hetero Junctions

Cupric oxide(CuO)is considered to be a promising material for photovoltaic applications.In this paper,p-CuO/n-Si junction solar cells were obtained by thermal oxidation of metallic copper films deposited on n-Si substrates at 400 ℃ for 5 h.X-ray diffraction patterns show that the as-prepared films are CuO with monoclinic crystalline structure.Hall effect measurement results show that CuO films are p-type conduction.A direct band-gap of ~1.57 eV for the CuO film is deduced from UV-Vis Absorbance spectra.Sola...     

Effect of multistep annealing on mechanical and surface properties of electroplated Cu thin films

Electroplated (EP) Cu films demonstrate a microstructural transition at room temperature, known as self-annealing, that involves grain growth and texture changes. In this paper, we have investigated the annealing behavior of EP Cu films grown on a Cu seed layer deposited on top of a TaN barrier layer. A grazing incident x-ray diffraction (GIXRD) pattern shows stronger x-ray reflections form Cu (111) and (220) planes but weaker reflections from (200), (311), and (222) planes in all the EP Cu samples. Nanoindentation was performed on all the samples using the continuous stiffness measurement technique. The elastic modulus varied from 121 GPa to 132 GPa, while the hardness varied from 1 GPa to 1.3 GPa, depending on the annealing conditions. The surface morphology and roughness of the Cu films were characterized using atomic force microscopy (AFM). The tribological properties of the copper films were measured using the Bench Top chemical mechanical polishing (CMP) tester (CETR, Inc., Campbell, CA). Nanoindentation was performed on the samples after CMP, and an increase in hardness and modulus was observed. This may be attributed to the work hardening of the Cu films during CMP.     

Atomic Layer Deposition of Aluminum Nitride Using Tris(diethylamido)aluminum and Hydrazine or Ammonia

Aluminum nitride (AlN _x ) films were obtained by atomic layer deposition (ALD) using tris(diethylamido) aluminum(III) (TDEAA) and hydrazine (N₂H₄) or ammonia (NH₃). The quartz crystal microbalance (QCM) data showed that the surface reactions of TDEAA and N2H4 (or NH₃) at temperatures from 150 to 225°C were self-limiting. The rates of deposition of the nitride film at 200°C for systems with N₂H₄ and NH₃ coincided: ~1.1 Å/cycle. The ALD AlN films obtained at 200°C using hydrazine had higher density (2.36 g/cm³, 72.4% of bulk density) than those obtained with ammonia (2.22 g/cm³, 68%). The elemental analysis of the film deposited using TDEAA/N2H4 at 200°C showed the presence of carbon (~1.4 at %), oxygen (~3.2 at %), and hydrogen (22.6 at %) impurities. The N/Al atomic concentration ratio was ~1.3. The residual impurity content in the case of N₂H₄ was lower than for NH₃. In general, it was confirmed that hydrazine has a more preferable surface thermochemistry than ammonia.     

Ultralow Dielectric Constant Tetravinyltetramethylcyclotetrasiloxane Films Deposited by Initiated Chemical Vapor Deposition (iCVD)

Simultaneous improvement of mechanical properties and lowering of the dielectric constant occur when films grown from the cyclic monomer tetravinyltetramethylcyclotetrasiloxane (V4D4) via initiated chemical vapor deposition (iCVD) are thermally cured in air. Clear signatures from silsesquioxane cage structures in the annealed films appear in the Fourier transform IR (1140 cm^?1) and Raman (1117 cm^?1) spectra. The iCVD method consumes an order of magnitude lower power density than the traditional plasma‐enhanced CVD, thus preserving the precursor's delicate ring structure and organic substituents in the as‐deposited films. The high degree of structural retention in the as‐deposited film allows for the beneficial formation of intrinsically porous silsesquioxane cages upon annealing in air. Complete oxidation of the silicon creates ‘Q’ groups, which impart greater hardness and modulus to the films by increasing the average connectivity number of the film matrix beyond the percolation of rigidity. The removal of labile hydrocarbon moieties allows for the oxidation of the as‐deposited film while simultaneously inducing porosity. This combination of events avoids the typical trade‐off between improved mechanical properties and higher dielectric constants. Films annealed at 410 °C have a dielectric constant of 2.15, and a hardness and modulus of 0.78 and 5.4 GPa, respectively. The solvent‐less and low‐energy nature of iCVD make it attractive from an environmental safety and health perspective.     

Stiff and Transparent Multilayer Thin Films Prepared Through Hydrogen‐Bonding Layer‐by‐Layer Assembly of Graphene and Polymer

Due to their exceptional orientation of 2D nanofillers, layer‐by‐layer (LbL) assembled polymer/graphene oxide thin films exhibit unmatched mechanical performance relative to any conventionally produced counterparts with similar composition. Unprecedented mechanical property improvement, by replacing graphene oxide with pristine graphene, is demonstrated in this work. Polyvinylpyrrolidone‐stabilized graphene platelets are alternately deposited with poly(acrylic acid) using hydrogen bonding assisted LbL assembly. Transmission electron microscopy imaging and the Halpin‐Tsai model are used to demonstrate, for the first time, that intact graphene can be processed from water to generate polymer nanocomposite thin films with simultaneous parallel‐alignment, high packing density, and exfoliation. A multilayer thin film with only 3.9 vol% of highly exfoliated, and structurally intact graphene, increases the elastic modulus (E) of a polymer multilayer thin film by 322% (from 1.41 to 4.81 GPa), while maintaining visible light transmittance of ≈90%. This is one of the greatest improvements in elastic modulus ever reported for a graphene‐filled polymer nanocomposite with a glassy (E > 1 GPa) matrix. The technique described here provides a powerful new tool to improve nanocomposite properties (mechanical, gas transport, etc.) that can be universally applied to a variety of polymer matrices and 2D nanoplatelets.