氧分压对溅射氧化钒薄膜结构和透光性能的影响

采用射频磁控溅射法,在K9抛光玻璃基底上沉积氧化钒(VOx)薄膜,研究在其他参数保持不变时氧分压参量对薄膜的结构、表面质量及透光性能的影响。利用表面轮廓仪、X射线衍射仪、原子力显微镜及分光光度计分别对样品的沉积速率、物相结构、表面形貌和紫外-近红外光透射率进行分析。结果表明,制备的VOx薄膜的晶相随氧分压不同发生改变,调整氧分压在可见-近红外光区域可获得弱吸收的光学膜,但氧分压过高只能获得低的薄膜沉积速率,氧分压对薄膜表面粗糙度及晶体生长模式也有不同程度的影响。本文对实验结果进行了分析和讨论。     

原位氧化硅钝化层对氧化钒薄膜光电特性的影响

氧化硅(SiOx)原位钝化层对氧化钒(VOx)薄膜电学特性的影响分析旨在改善像元微桥结构的光学吸收特性,提高热敏VOx薄膜层的方阻和电阻温度系数(TCR)稳定性。采用离子束溅射沉积50 nm VOx薄膜后,紧接着沉积30 nm SiOx钝化层。通过原位残余气体分析仪(RGA)和衬底温度控制,调节氧化钒薄膜中的氧含量,分析了VOx单层膜、SiOx/VOx双层膜的电学特性随工艺温度的变化规律,原位残余气体分析仪(RGA)和150℃加温工艺提高了VOx热敏层薄膜的方阻和电阻温度系数稳定性。     

SiO_2/VO_x多层复合薄膜的结构与性能研究

采用射频磁控溅射法,在普通玻璃基片上成功制备了SiO2/VOx多层复合薄膜。采用X射线衍射仪(XRD)、傅立叶变换红外光谱仪(FTIR)、紫外可见光分光光度计(UV-Vis)和X射线光电子能谱仪(XPS)研究了薄膜的物相、热致相变特性及V的价态。结果表明,薄膜中VO2晶体具有(110)择优取向生长;SiO2底膜有助于多层复合薄膜中VO2相结晶度的提高,可使V4+摩尔分数由53.9%提高至66.0%;同时,SiO2增透膜的增透效果明显,增透膜沉积时间为60 min时,可使SiO2/VOx/SiO2多层复合薄膜可见光透过率提高至51%;制得的SiO2/VOx/SiO2多层复合薄膜具有较好的热致相变特性。     

磁控溅射工艺对VOx薄膜结构和性能的影响

以高纯氧和高纯氩为气源,通过改变薄膜的制备工艺,用直流磁控溅射法在玻璃和单晶硅片上制备了VOx 薄膜,并对其进行了退火处理。借助LCR测试仪和X射线衍射仪,对VOx薄膜的电阻温度系数、晶体结构进行了检测。结果表明,当溅射 气压为1.5Pa,功率为100W,时间为1h,氧氩比为0.8∶25时, 经450℃退火后,玻璃基片上制备的薄膜的电阻温度系数(TCR)超过-0.02/℃,其结构和性能最好。同时对比了玻璃和单晶硅基片对VOx 薄膜的生长、性能和结构的影响。当氧氩比为0.8∶25时,单晶硅片上制得的VOx薄膜的质量和性能最好。     

多靶磁控共溅射纳米Ta-Al-N薄膜的阻挡性能研究

采用磁控反应共溅射方法制备了纳米Ta-Al-N薄膜,并原位制备了Cu/Ta-Al-N薄膜,对薄膜进行了热处理。用四探针测试仪、X射线衍射仪(XRD)、扫描电镜(SEM)、原子力显微镜(AFM)以及台阶仪等研究了退火对薄膜结构及阻挡性能的影响。结果表明,Ta-Al-N薄膜具有优良的热稳定性,保持非晶态且能对Cu有效阻挡的温度可达800°C;同时发现在900°C退火5 min后,薄膜开始晶化,在Cu/Ta-Al-N/Si界面处生成了Cu3Si等相,表明此时Ta-Al-N薄膜阻挡层开始失效。     

L-MBE法制备以ZnO为沟道层的薄膜晶体管

采用激光分子束外延法(L-MBE)在SiNx/Si(111)衬底上制备了高质量的ZnO薄膜,用X射线衍射(XRD)和原子力显微镜(AFM)对薄膜的晶体结构、表面形貌进行了表征,结果表明ZnO薄膜有高度的c轴择优取向,薄膜表面平整致密.并以ZnO薄膜为沟道层制作了薄膜晶体管(ZnO-TFT),该晶体管工作在n沟道增强模式,阈值电压为17.5V,电子的场迁移率达到1.05cm2/(V·s).     

L-MBE法制备以ZnO为沟道层的薄膜晶体管

采用激光分子束外延法(L-MBE)在SiNx/Si(111)衬底上制备了高质量的ZnO薄膜,用X射线衍射(XRD)和原子力显微镜(AFM)对薄膜的晶体结构、表面形貌进行了表征,结果表明ZnO薄膜有高度的c轴择优取向,薄膜表面平整致密.并以ZnO薄膜为沟道层制作了薄膜晶体管(ZnO-TFT),该晶体管工作在n沟道增强模式,阈值电压为17.5V,电子的场迁移率达到1.05cm2/(V·s).     

溅射功率对AlN/ZnO薄膜结构形貌的影响

采用直流反应磁控溅射法以ZnO为缓冲层在Si衬底上制备了AlN/ZnO薄膜。利用台阶仪、X线衍射(XRD)仪和原子力显微镜(AFM)对不同溅射功率下制备的AlN/ZnO薄膜的厚度、结构及表面形貌进行测试表征。结果表明,不同溅射功率下生长的AlN薄膜都沿(002)择优生长,且随着功率的增大,薄膜的沉积速率增加,晶粒长大,AlN薄膜的(002)取向性变好。同时还利用扫描电子显微镜(SEM)对在优化工艺下制得AlN/ZnO薄膜断面的形貌进行表征,结果显示AlN薄膜呈柱状生长。     

非制冷红外探测器用VO_x薄膜的制备

介绍了一种采用反应溅射工艺 ,通过控制不同气氛的分布制备VOx 薄膜的方法 ,并制备出电阻温度系数 (TCR)优于 - 2 %的非制冷红外探测器用VOx 薄膜。其XPS、XRD分析结果表明 ,薄膜的生长情况与制备工艺条件有密切关系。     

退火温度对ZnO/PZT薄膜结构及电阻率的影响

采用射频反应磁控溅射法在Pb(Zr0.52Ti0.48)O3(PZT)/Pt/Ti/SiO2/Si基片上制备了ZnO薄膜,利用X线衍射仪(XRD)、原子力显微镜(AFM)、霍尔效应测试系统等对不同退火温度下制备薄膜的结构、形貌及电阻率等进行了分析表征。结果表明,退火温度600℃的ZnO薄膜(002)择优取向较好,晶粒大小均匀,表面平整致密。随着退火温度的增大,电阻率先下降后升高,600℃时ZnO薄膜电阻率达最小。     

Al_2O_3过渡层厚度对AZO薄膜性能的影响研究

采用磁控溅射法,在预先沉积了Al2O3过渡层的玻璃衬底上制备了性能优良的AZO薄膜。借助XRD、AFM、四探针仪和分光光度计对AZO薄膜的结构、表面形貌以及电学和光学性质进行了表征,并研究了Al2O3过渡层厚度对AZO薄膜性能的影响。结果表明:Al2O3过渡层的添加对AZO薄膜的表面形貌有一定影响;AZO薄膜的结晶质量随着过渡层厚度的增加先上升后下降;AZO薄膜的电阻率因过渡层的添加而明显降低,特别是在AZO薄膜较薄时;在添加了1～3 nm厚的过渡层后,160 nm厚的AZO薄膜的电阻率下降了44%左右;AZO薄膜的可见光透射率和光学带隙基本不受过渡层影响。     

磁控溅射结合快速热处理制备相变氧化钒薄膜

采用直流对靶磁控溅射结合快速热处理工艺制备了具有金属-半导体相变特性的氧化钒(VOx)薄膜。利用XRD,XPS和SEM对薄膜结晶结构、薄膜中V的价态与组分及表面微观形貌进行分析,利用四探针测试法及太赫兹时域频谱系统对薄膜的电学和光学特性进行测量。结果表明:新制备VOx薄膜以非晶态V2O5为主;350℃,30 s快速热处理后,薄膜中V的整体价态降低,表面颗粒分布更加致密;500℃,30 s快速热处理后,薄膜中VO2(002)向单斜结构的VO2(011)转变,VO2(011)占主要成分,薄膜显示出明显的金属-半导体相变特性,方块电阻下降达到3个数量级,太赫兹透过率下降接近70%,热致相变性能良好。     

MgO和STO基片上制备YBCO高温超导薄膜生长研究

用AFM和XRD研究在MgO和STO基片上外延生长2-200nm的YBCO高温超导薄膜的生长机制。采用倒筒式直流溅射装置,首次实现单轴驱动双轴旋转技术,本质上实现同时在MaO基片和STO基片上沉积同一均匀厚度的YBCO薄膜。     

Scaling Behavior of Resistive Switching in Epitaxial Bismuth Ferrite Heterostructures

Resistive switching (RS) of (001) epitaxial multiferroic BiFeO₃/La_0.67Sr_0.33MnO₃/SrTiO₃ heterostructures is investigated for varying lengths scales in both the thickness and lateral directions. Macroscale current–voltage analyses in conjunction with local conduction atomic force microscopy (CAFM) reveal that whilst both the local and global resistive states are strongly driven by polarization direction, the type of conduction mechanism is different for each distinct thickness regime. Electrode‐area dependent studies confirm the RS is dominated by an interface mechanism and not by filamentary formation. Furthermore, CAFM maps allow deconvolution of the roles played by domains and domain walls during the RS process. It is shown that the net polarization direction, and not domain walls, controls the conduction process. An interface mechanism based on barrier height and width alteration due to polarization reversal is proposed, and the role of electronic reconstruction at the interface is further investigated.     

Study of diffusion barrier properties of ionized metal plasma (IMP) deposited TaN between Cu and SiO2

The diffusion barrier properties of IMP deposited TaN between Cu and SiO₂ have been investigated in the Cu (200 nm)/TaN (30 nm)/SiO₂ (250 nm)/Si multi-layer structure. The IMP-TaN thin film shows better Cu diffusion barrier properties than chemical vapor deposition (CVD) and conventional physical vapor deposition (PVD) deposited TaN films. The thermal stability was evaluated by electrical measurement and X-ray diffraction (XRD) analysis. As a main part of thermal stability studies, the atomic intermixing, new compound formation and phase transitions in the test structure were also studied. Furthermore, a failure mechanism was also examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), secondary ion mass spectroscopy (SIMS) and Rutherford backscattering spectroscopy (RBS) in conjunction with electrical measurements. The 30 nm thick IMP-TaN was found to be stable up to 800°C for 35 min.     

SiC薄膜的制备及其对气氛的响应研究

在CH4,H2,SiH4混合气体中用热丝化学气相沉积(HFCVD)法生长SiC薄膜。利用XRD、原子力显微镜(AFM)对SiC薄膜的表面形貌和晶体结构进行测试分析,结果表明,薄膜的确是SiC,其厚度为310nm。对该薄膜在较高温度(250℃)下进行气敏特性测试,发现其对乙醇、乙醚有较好的敏感特性。进一步研究表明,不同的薄膜制备工艺条件对薄膜的气敏特性有一定的影响,其中H2流量,掺杂(N2)浓度对薄膜气敏特性影响较大。     

Optimization of physical properties of vacuum evaporated CdTe thin films with the application of thermal treatment for solar cells

This paper reports the optimization of physical properties of cadmium telluride (CdTe) thin films with the application of thermal treatment. The films of thickness 650 nm were deposited on glass and indium tin oxide (ITO) coated glass substrates employing vacuum evaporation followed by thermal annealing in the temperature range 250–450 °C. The films were characterized using X-ray diffraction (XRD), source meter and atomic force microscopy (AFM) for structural, electrical and surface topographical properties respectively. The X-ray diffraction patterns reveal that films are polycrystalline with predominant zinc-blende structure having preferred reflection (111). The structural parameters are calculated and discussed in detail. The current–voltage characteristics show Ohmic behavior and the electrical conductivity is found to increase with annealing treatment. The AFM studies show that the surface roughness of films is observed to increase with annealing. The experimental results reveal that the thermal annealing plays an important role to enhance the physical properties of CdTe thin films and annealed films may be used as absorber layer in CdTe/CdS solar cells.     

PLD法制备ZnO薄膜的退火特性和蓝光机制研究

通过脉冲激光沉积(PLD)方法,在O2中和100～500℃衬底温度下,用粉末靶在Si(111)衬底上制备了ZnO薄膜,在300℃温度下生长的薄膜在400～800℃温度和N2氛围中进行了退火处理,用X射线衍射(XRD)谱、原子力显微镜(AFM)和光致发光(PL)谱表征薄膜的结构和光学特性。XRD谱显示,在生长温度300℃时获得较好的复晶薄膜,在退火温度700℃时获得最好的六方结构的结晶薄膜;AFM显示,在此退火条件下,薄膜表面平整、晶粒均匀;PL谱结果显示,在700℃退火时有最好的光学特性。     

Bias voltage dependence properties of Nb-doped indium tin oxide thin films by RF magnetron sputtering at room temperature

Niobium doped indium tin oxide (ITO:Nb) thin films were fabricated on glass substrates by RF magnetron sputtering from one piece of ceramic target material at room temperature. The bias voltage dependence of properties of the ITO:Nb films were investigated by adjusting the bias voltage. Structural, electrical and optical properties of the films were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), UV–visible spectroscopy, and electrical measurements. XRD patterns showed a change in the preferential orientations of polycrystalline crystalline structure from (222) to (400) crystal plane with the increase of negative bias voltage. AFM analysis revealed that the smooth film was obtained at a negative bias voltage of -120 V. The root mean square (RMS) roughness and the average roughness are 1.37 nm and 1.77 nm, respectively. The films with the lowest resistivity as low as 1.45×10⁻⁴ Ω cm and transmittance over 88% have been obtained at a negative bias voltage of −120 V. Band gap energy of the films, depends on substrate temperature, varied from 3.56 eV to 3.62 eV.     

Sb掺杂SnO2/SiO2纳米光学气敏薄膜的制备及其性质

采用溶胶凝胶(sol-gel)工艺制备了Sb掺杂SnO2/SiO2复合膜。通过X射线衍射(XRD)、傅立叶变换红外谱(FT-IR)及原子力显微镜(AFM)表征了薄膜样品的物相结构与表面形貌,利用紫外-可见光谱研究了复合薄膜光学特性．利用p-偏振光双面反射法对薄膜的气敏特性进行了测试。实验结果表明,薄膜中的晶粒具有纳米尺寸(～35nm)的大小．比表面积大,孔隙率高;薄膜的透光率高,可见光波段近95％;纳米Sb：SnO2：SiO2复合膜的气敏灵敏度高于纯SnO2薄膜及Sb掺杂的SnO2薄膜。