Investigation of ZnO:Al Thin Films Prepared by RF Magnetron Sputtering

ZnO:Al（AZO）薄膜因其低电阻率与高可见光区透射率有望替代ITO，成为主要的透明导电氧化物（TCO）材料。相对于ITO材料，AZO薄膜原材料丰富，价格低廉且无污染，是理想的透明导电氧化物材料。目前用以制备AZO薄膜的方法有多种，其中磁控溅射技术因其高的沉积速率与均匀性被认为是重要的制备AZO薄膜的技术之一。 本论文利用射频磁控溅射技术，以ZnO:Al2O3(2wt%Al2O3)为靶材在石英玻璃衬底上制备多晶AZO薄膜。为了与半导体制造领域的剥离工艺相兼容，所有样品均在室温下沉积。同时应用X射线衍射仪（XRD）、原子力显微镜（AFM）、扫面电子显微镜（SEM）、俄歇电子能谱仪（AES）、...Aluminum-doped zinc oxide (AZO) thin films with low resistivity and high transparency in visible range are promising as alternatives to ITO for transparent conducting oxide (TCO), sicne indium is a very expensive and scarce material, while AZO, the source materials of which are inexpensive and non-toxic, is the best candidate. Nowadays, various technologies have been reported to produce AZO thin f...学位：理学硕士院系专业：物理与机电工程学院物理学系_凝聚态物理学号：2005130163

Effect of RF power on the structure and properties of ZnO∶Al films deposited by magnetron sputtering

采用RF磁控溅射技术以ZnO:Al2O3(2 wt%Al2O3)为靶材在石英玻璃衬底上制备多晶ZnO:Al(AZO)薄膜,通过XRD、AFM、AES以及Hall效应、透射光谱、折射率等手段研究了RF溅射功率(50~300 W)对薄膜的组织结构和电学,光学性能的影响。分析表明:所制备的AZO薄膜具有c轴择优取向,并且通过对不同功率下薄膜载流子浓度与迁移率的研究发现对于室温下沉积的AZO薄膜,晶粒间界中的O原子吸附是影响薄膜电学性能的主要因素。同时发现当功率为250 W时薄膜的电阻率降至最低(3.995×10-3Ω.cm),可见光区平均透射率为91%。Aluminum doped zinc oxide films are deposited by magnetron sputtering using a zinc oxide target doped with Al2O3(2 wt%.) with different RF powers on quartz substrate.The structural and compositional characteristics of the films are investigated by XRD,AFM,SEM,AES and XPS.respctively,while the electrical and optical properties of the thin films are studied by the Hall measurement and spectrophotometry,respectively.It has been found that all films deposited are c-axis preferred orientation perpendicular to the substrate with porous crystalline structure.The lowest resistivity obtained in this study is 3.9×10-3 Ω·cm for the film deposited at 250 W,and the average transmittance is 91% in the visible range.By comparing the samples deposited at various RF power,the oxygen absorption in the grain boundaries is the dominant factor which influences the electrical property of the AZO thin film

Structural,Electrical,and Optical Properties of Transparent Conductive Al-Doped ZnO Films Prepared by RF Magnetron Sputtering

室温下采用RF磁控溅射技术在石英衬底上制备了多晶ZnO:Al(AZO)透明导电薄膜,通过XRD,AFM,AES,Hall效应及透射光谱等测试研究了RF溅射功率、氩气压强对薄膜的结构、电学和光学性能的影响.分析表明:在最优条件下(溅射功率为250W,氩气压强为1.2Pa时),180nmAZO薄膜的电阻率为2.68×10-3Ω.cm,可见光区平均透射率为90%,适合作为发光二极管和太阳能电池的透明电极.所制备的AZO薄膜具有c轴择优取向,晶粒间界中的O原子吸附是限制薄膜电学性能的主要因素.Highly conductive transparent Al-doped zinc oxide(AZO)films with highly(002)-preferred orientation were successfully deposited on glass substrates at room temperature by RF magnetron sputtering.Optimization of deposition parameters was based on sputtering RF power and Ar pressure in the vacuum chamber.AZO films of 180nm with an electrical resistivity as low as 2.68×10-3 Ω·cm and an average optical transmission of 90% in the visible range were obtained at RF power of 250W and Ar pressure of 1.2Pa.The effect of chemisorption of oxygen on the grain boundary would capture electrons from conduction band and lead the formation of potential barriers among the crystallites,which will influence the electric property of the AZO thin films.The films have satisfactory properties of low resistance and high transmittance for application as transparent conductive electrodes in light emitting diodes(LEDs)and solar cells

Effect of Ar Pressure on the Structure and Properties of ZnO∶Al Films Deposited by RF Magnetron Sputtering

以ZnO∶Al2O3为靶材在石英玻璃衬底上射频磁控溅射制备多晶ZnO∶A l(AZO)薄膜,通过XRD、AFM以及H all效应、透射光谱等测试研究了RF溅射压强对薄膜结构、电学与光学性能的影响。分析表明:所制备的薄膜具有c轴择优取向,当压强为1.2Pa时薄膜的电阻率降至最低(2.7×10-3Ω·cm)。薄膜在可见光区平均透射率高于90%,光学带隙均大于本征ZnO的禁带宽度。Aluminum doped zinc oxide films were deposited by RF magnetron sputtering using a zinc oxide target doped with Al2O3 with different Ar pressure.The structural characteristics of the films were investigated by XRD and AFM while the electric and optical properties of the thin films were studied by the Hall measurement and optical spectroscopy,respectively.All of the films deposited were c-axis preferred orientation perpendicular to the substrate.The lowest resistivity obtained in this study was for the film deposited at Ar pressure of 1.2Pa,and the average transmittance is larger than 90% in the visible range for all samples.The optical band gap of the films is in the range of 3.53—3.66eV which is larger than the band gap of intrinsic ZnO

Fabrication of 4H-SiC MSM Photodiode Linear Arrays

采用Ni/Au作为肖特基接触制备了一维阵列MSM4H-SiC紫外光电探测器,并测量和分析了阵列器件的I-V、光谱响应特性.结果表明,阵列探测器性能均匀性好,击穿电压均高于100V.阵列中单器件暗电流小,在偏压为20V的时候,最大暗电流均小于5pA(电流密度为5nA/cm2),光电流比暗电流高3个数量级以上.其光谱响应表明,单器件在电压为20V时的响应度约为0.09A/W,比400nm时的比值均大5000倍,说明探测器具有良好的紫外可见比.Metal-semiconductor-metal(MSM)photodetector linear arrays of 40 pixels based on 4H-SiC,in which nickel Schottky contacts are used,are designed,fabricated,and characterized.Current-voltage and spectral responsivity measurements are carried out at room temperature.The linear arrays show uniform performances,including responsibility,breakdown voltage,and low leakage current.The breakdown voltage of the unit is beyond 100V.The detector shows a peak responsivity of about 0.09A/W,a dark current smaller than 5pA at 20V,and a displayed peak response wavelength at 290nm.The ratio of responsivity at 290nm to that of at 400nm is more than 5000,implying that the photodetector has an improved visible blind performance