直流磁控溅射工艺对ITO薄膜光电性能的影响

采用直流磁控溅射系统在玻璃衬底上制备了氧化铟锡(ITO)薄膜。通过X射线衍射仪、扫描电子显微镜、分光光度计、Hall效应测试系统研究了热退火与原位生长、衬底温度、直流溅射功率对薄膜结构、表面形貌以及光电性能的影响。结果表明:与室温生长并经410℃热退火后的薄膜相比,410℃原位生长可获得光电性能更好的薄膜;随着衬底温度的增加,电阻率单调减小,光学吸收边出现蓝移;在溅射功率为85 W时薄膜的光电性能达到最佳。在衬底温度为580℃、溅射功率为85 W的工艺条件下,可制备出电阻率为1.4×10~(–4)?·cm、可见光范围内平均透过率为93%的光电性能优异的ITO薄膜。     

溅射功率对ZnO:Ga薄膜的结构和光电性能的影响

采用磁控溅射法在玻璃衬底上制备了ZnO:Ga薄膜,并使用XRD、SEM、UV-VIS和霍尔测试仪等测试手段分析研究了不同功率对ZnO:Ga薄膜的结构以及光学和电学性能的影响。实验结果表明:制备的ZnO:Ga薄膜为六角纤锌矿结构,且具有明显的C轴择优取向;随着溅射功率逐渐从100W增加到175W,玻璃衬底上薄膜的结晶程度越来越高,当溅射功率超过175W时,结晶强度减弱;在可见光范围内,薄膜样品的透过率均达到84%以上,具有良好的透光性能;同时我们发现实验制得的薄膜导电率随着溅射功率的增加而加强。     

蓝宝石衬底上SiO2薄膜的制备与光学性能

以硅单晶为靶材,高纯的Ar和O2气分别为溅射气体和反应气体,采用射频磁控反应溅射法,在蓝宝石衬底上制备了SiO2薄膜,溅射的工艺参数范围是：射频功率为50～100W,样品托背面温度为25～400℃,沉积速率为4～6nm／min。对影响薄膜质量的工艺参数进行了分析,探索出使蓝宝石镀膜后的红外透过率有最大幅度提高的最佳工艺条件。结果表明,所制备的SiO2薄膜与蓝宝石衬底结合牢固;在3～5μm波段对蓝宝石衬底有明显的增透作用。与其它镀膜技术相比,射频磁控反应溅射法可以在较低的温度下制备出SiO2薄膜。     

Al2O3掺量及氧气分压对直流磁控溅射法制备铝掺杂氧化锌薄膜性能的影响

制备了掺杂质量数为1％,2％,3％和4％Al2O3的ZnO靶材。用直流磁控溅射法在玻璃衬底上制备了ZnO;Al(ZAO)透明导电薄膜试样。用X射线衍射和扫描电镜分析了薄膜的物相及表面形貌。用四探针法测试了薄膜的电性能。用紫外-可见光谱仪测试了试样的可见光透过率。结果表明：溅射气氛中氧气的存在降低薄膜的电导率,对薄膜试样的可见光透过率影响不大;用含3％Al2O3的ZnO靶材制备的薄膜的电导率最高。讨论了氧气分压和Al2O3的掺杂量对ZAO薄膜的结构和性能的影响。     

金属有机化学气相沉积法制备Al掺杂ZnO透明导电膜

采用自行开发的金属有机化学气相沉积(metal organic chemical vapor deposition,MOCVD)法,以乙酰丙酮锌和乙酰丙酮铝分别为锌源和铝源,以氮气为载气,在玻璃衬底上制备Al掺杂ZnO(Al-doped ZnO,ZAO)薄膜。通过改造MOCVD设备提高制备薄膜的稳定性和均匀性,研究了基片温度、载气流量、水蒸气等沉积条件对薄膜结构,沉积速率及其光、电性能的影响。用扫描电子显微镜、X射线衍射、紫外-可见分光光度计和四探针双电测电阻仪分别观察薄膜形貌结构,并测试其光、电性能。结果表明:薄膜为均匀、致密的纳米多晶薄膜,具有六角纤锌矿结构,且呈c轴择优取向生长;薄膜的(002)衍射峰与纯ZnO相比向低角度方向偏移,表明Al进入了ZnO晶格,并导致晶格膨胀;薄膜的紫外-可见光谱透过率在85%以上;电阻率最小可达10-4??cm。     

氧气流量和溅射功率对脉冲直流磁控溅射制备Nb2O5薄膜性能的影响

采用非对称双极性脉冲直流磁控溅射系统在玻璃衬底上制备了Nb_2O_5薄膜,重点研究了O_2流量和溅射功率对薄膜结构、成分、形貌和光学性能的影响。XRD结果表明:所有制备的薄膜均为非晶结构;XPS用于分析不同O_2流量下沉积的薄膜表面Nb的化学状态,O_2流量达到4.0 sccm以上才能得到满足化学计量比的Nb_2O_5薄膜;AFM结果显示:随着O_2流量的增加,薄膜表面更加平滑、均匀,而溅射功率为80 W时所制备的Nb_2O_5薄膜表现出最大的表面粗糙度大约为1.59 nm;光学结果表明,随着O_2流量增加,可见光区的平均光学透过率逐渐增大,但溅射功率超过40 W,溅射功率对薄膜可见光区的透过率影响很小;此外,通过改变O_2流量和溅射功率,可以很好地调节薄膜的折射率,从而更加便于消影玻璃中光学介质膜系的设计与生长。     

磁控溅射AZO工艺中沉积温度的研究

在采用磁控溅射制备AZO薄膜的过程中,AZO薄膜的光电性能取决于镀膜过程中的各种工艺参数,包括:溅射气压、沉积温度、溅射功率、靶基距等。本文主要研究在固定其它工艺参数不变的情况下,通过改变玻璃基板沉积温度在200℃、250℃、300℃、350℃、400℃、450℃、500℃的情况下分别制备AZO薄膜,通过分析研究玻璃基板沉积温度变化对制备AZO薄膜光电性能及结构的影响,筛选出制备高质量AZO膜的最佳沉积温度。     

用MWECR CVD系统制备具有非晶/微晶两相结构的硅薄膜研究

用微波电子回旋共振化学气相沉积(MWECR CVD)系统制备了具有非晶/微晶两相结构的硅薄膜,研究了沉积温度和沉积压力等对制备微晶硅薄膜的结构和电学特性的影响.结果表明:较低的反应压和较高的衬底温度有利于获得非晶/微晶两相结构的硅薄膜,当反应压为0.7 Pa、衬底温度为170℃时,得到非晶/微晶两相结构的硅薄膜晶相体积比约为30%;具有这种晶相体积比的非晶/微晶两相结构的硅薄膜,μτ乘积值约为10-5量级左右,比不含微晶成分的氢化非晶硅样品的μτ乘积值大约2个量级,同时这种晶相体积比的非晶/微晶两相结构的硅薄膜的光敏性在103～104左右,其兼具很好的光电导稳定性和优良的光电特性,是制备非晶硅太阳电池的器件级本征层材料.     

薄膜厚度对Al掺杂ZnO薄膜性能的影响

采用直流磁控溅射技术,以氧化锌铝陶瓷靶为靶材,在玻璃衬底上制备了ZnO：Al（ZAO）薄膜样品。在其他参数不变的情况下,由不同溅射时间得到了不同厚度的薄膜,研究了薄膜的结构性质、电学和光学性质随薄膜厚度的变化关系。实验结果表明：在薄膜厚度为500 nm时,ZAO薄膜具有最优化的光电性能,电阻率为1.68×10-3Ω.cm,可见光区平均透射率为90.3%。     

蓝宝石衬底表面SiO2薄膜的应力分析

采用射频磁控反应溅射法分别在Si和蓝宝石衬底上沉积SiO2薄膜.通过改变沉积薄膜的工艺参数,考察反应气体流量比、沉积温度、射频功率等因素对SiO2薄膜内应力的影响.采用压痕裂纹法分析了镀膜前后蓝宝石的表面应力.结果表明:制备SiO2薄膜时,工艺参数影响SiO2薄膜的成分,当O2/Ar流量比值为1.25,衬底温度为300℃,射频功率为100 W时,可以制备出化学计量比的SiO2薄膜,此时薄膜中的内应力较小;制备的SiO2薄膜呈压应力状态,镀SiO2薄膜可以改变蓝宝石的表面应力,蓝宝石的表面应力已由原来的拉应力变为压应力.     

Effect of the Growth Parameters on Nonlinear Optical Properties of Al‐Doped ZnO Nano Films

The objective of this research work is to provide a systematic method to perform test and evaluation on the nonlinear optical properties of Al‐doped ZnO nano thin film structure for designing a high‐performance optical‐electronic structure. Some different kinds of samples can be manufactured for testing. The samples are designed by changing technical parameters such as sputtering power of Al and ZnO, pressure and sputtering time and each parameter has three levels. The test results show that the main factor is the sputtering power of Al, which means the doping density of Al. In the meantime, the Maxwell–Garnett theory is used to investigate the optical prosperities of Al‐doped ZnO nano thin films in the visible range. The optical band gap of Al‐doped ZnO nano thin films increases with the increasing of Al doping density, but it becomes slowly when the doping density is more than 16.0%. The results and the investigation method are useful for designing and manufacturing for nano thin films.     

Room temperature preparation of c axis oriented ZnO films on Si(100), SiO2, and ZnO substrates by rf magnetron sputtering

Abstract

Growth of ZnO thin films with c axis (002) orientation has been demonstrated at room temperature on Si(100), SiO₂, and amorphous ZnO substrates by the rf magnetron sputtering method. The structural properties of the ZnO thin films were investigated with varying rf power. X-ray diffraction analysis revealed that increasing rf power helped to increase the c axis lattice constant and grain size, regardless of substrate material. Scanning electron microscopy indicated that the structural morphology of the ZnO films was not dependent on the substrate material.     

Characteristics of Optimized Al:ZnO sputtering targets prepared by nanostructured powder

Optimized Al:ZnO sputtering target was prepared by cold isostatic pressing (CIP) using nanostructured zinc oxide powder and aluminum oxide powder as raw material. Compared with the target prepared by conventional raw materials, the performance of the optimized Al:ZnO sputtering target is greatly improved. The microstructure of the optimized Al:ZnO sputtering target is refined and its average grain size is less than 5 μm with 99.7% theoretical density. Al:ZnO thin films of both optimized and conventional targets were prepared by RF magnetron sputter and their properties were characterized, respectively. The Al:ZnO thin films obtained by optimized target feature better uniformity and compactness, and the internal stress is −378.8 MPa, which is nearly 2/3 lower than that of the conventional target. The film obtained by optimized targets also features a 97% IR transmittance, 1.71 nm Rq surface roughness and non-offset (002) XRD peak. It can be speculated that the optimized Al:ZnO target has great potential to prepare micrometer scale Al:ZnO films and employed in thin-film ZnO device industry.     

Effect of gas-timing technique on structure and optical properties of sputtered zinc oxide films

Zinc oxide thin films were prepared by the RF magnetron sputtering using a gas-timing technique whereby the flow of argon into the sputtering chamber was controlled by an on–off sequence. With this technique, polycrystalline ZnO thin films on glass substrates have been achieved without any thermal treatment of the substrate. In addition, the RF power and the gas-timing sequence can be fine-tuned to produce the hexagonal structure of ZnO thin films. X-ray diffraction (XRD) measurements confirm a (0 0 2) plane oriented wurtzite structure ZnO thin films. The optimized conditions for this hexagonal structure are an RF power of 30 W and an on–off gas-timing sequence of 50:2 s. The root mean square surface roughness of ZnO thin films measured by atomic force microscopy are in the range of 6.4–11.5 nm. The optical transmittance of ZnO thin films is over 85% in the visible range.     

射频磁控溅射法制备FC/ZnO杂化材料及其基本性质

采用射频磁控溅射法,首先以聚四氟乙烯（PTFE）为靶,氩气为载气,在聚对苯二甲酸乙二醇酯（PET）基底上沉积氟碳（FC）膜;然后以金属锌为靶,氩气为载气,氧气为反应气体,在FC膜上再沉积一层ZnO膜而形成FC/ZnO有机-无机纳米杂化材料。用AFM、XPS、UV以及静态接触角测定仪对杂化材料的基本性质进行了研究。结果表明,该法制得的杂化材料是由纳米粒子组成的岛状结构,岛的表面起伏不平。其生长模式是一种依附于有机核的沉积-扩张生长。杂化材料具有较好的紫外吸收特性,这是由于其分子结构中含有π-π共轭双键、表面的不平整性以及纳米氧化锌粒子对紫外光的吸收共同作用的结果。静态水接触角均大于90°,呈现出良好的疏水性。     

The optical and electrical properties of ZnO:Al thin films deposited at low temperatures by RF magnetron sputtering

Several ZnO:Al thin films have been successfully deposited on glass substrates at different substrate temperatures by RF (radio frequency) magnetron sputtering method. Effects of the substrate temperatures on the optical and electrical properties of these ZnO:Al thin films were investigated. The UV–VIS–NIR spectra of the ZnO:Al thin films revealed that the average optical transmittances in the visible range are very high, up to 88%. X-ray diffraction results showed that crystallization of these films was improved at higher substrate temperature. The band gaps of ZnO:Al thin films deposited at 25 ℃, 150 ℃, 200 ℃, and 250 ℃ are 3.59 eV, 3.55 eV, 3.53 eV, and 3.48 eV, respectively. The Hall-effect measurement demonstrated that the electrical resistivity of the films decreased with the increase of the substrate temperature and the electrical resistivity reached 1.990×10^?3 Ω cm at 250 ℃.     

Deposition and characterization of AZO thin films on flexible glass substrates using DC magnetron sputtering technique

Al-doped zinc oxide (AZO) thin films were deposited onto flexible ultra-thin glass substrates by using a direct current (DC) magnetron sputtering process. The effects of sputtering power, working pressure and substrate temperature on the morphology and optoelectronic performances of AZO films were investigated. The optimal sputtering power, working pressure and substrate temperature for AZO film were determined to be 100 W, 0.9 Pa and 150 ℃, respectively. Further increasing or decreasing the sputtering power, working pressure and substrate temperature degrades the quality of AZO films. XRD patterns show all as-sputtered AZO thin films are preferred to grow along <0002> direction. Moreover, the largest grain size, which depicts the best microstructure of AZO films, matches with the smallest stress value. It can be seen from SEM images that the surface is smooth and dense. The smallest value of the resistivity is 1.784×10⁻³ Ω cm and the average transmittance of all AZO films in the visible range is about 80%. The X-ray photoelectron spectroscopy spectra show that the amount of Al element in the AZO film is very small.     

Deposition of F-doped ZnO transparent thin films using ZnF2-doped ZnO target under different sputtering substrate temperatures

Highly transparent and conducting fluorine-doped ZnO (FZO) thin films were deposited onto glass substrates by radio-frequency (RF) magnetron sputtering, using 1.5 wt% zinc fluoride (ZnF₂)-doped ZnO as sputtering target. Structural, electrical, and optical properties of the FZO thin films were investigated as a function of substrate temperature ranging from room temperature (RT) to 300°C. The cross-sectional scanning electron microscopy (SEM) observation and X-ray diffraction analyses showed that the FZO thin films were of polycrystalline nature with a preferential growth along (002) plane perpendicular to the surface of the glass substrate. Secondary ion mass spectrometry (SIMS) analyses of the FZO thin films showed that there was incorporation of F atoms in the FZO thin films, even if the substrate temperature was 300°C. Finally, the effect of substrate temperature on the transmittance ratio, optical energy gap, Hall mobility, carrier concentration, and resistivity of the FZO thin films was also investigated.     

Optoelectronic performances on different structures of Al‐doped ZnO

ZnO films and Al‐doped ZnO (AZO) films were deposited on p‐Si substrate by magnetron sputtering to investigate its chemical composition, structural and photoelectric properties. XRD and FTIR show that Al ions can enter into the substitutional and interstitial site of ZnO crystal, and O atoms in AZO films are more abundant. Three different structures of Al‐doped ZnO (substitutional Al, interstitial Al, and O‐rich Al‐doped ZnO) were built using first‐principles method based on experimental results, charge density difference, and density of States (DOS) illustrate that there are strong ionic interactions between Al and O atoms in substitutional Al‐doped ZnO, moreover, substitutional and interstitial Al doping both are beneficial to N type, but oxygen‐enriched ZnO is not conducive to N type. Furthermore, the optical properties of 3 different Al‐doped ZnO structures were investigated respectively. Compared with pure ZnO, the real and imaginary part of dielectric function of O‐rich and interstitial Al have a significant increase and move to lower energy (red shift), the reflectivity of O‐rich is 3 times of pure ZnO and substitutional Al‐doped ZnO. The results are hoped to be helpful to study AZO thin film and predict the properties of Al‐doped ZnO.     

Effects of electron doping on the d0 magnetism in N-implanted ZnO and ZnAlO films

In this paper, N ions are implanted into ZnO and ZnAlO films with different carrier concentrations prepared by radio frequency reactive magnetron sputtering on sapphire substrates. The structural, electrical, optical and magnetic properties of N-doped and (Al, N) co-doped ZnO films is investigated, and the particular emphasis is placed on the effects of carrier concentration on the defects induced magnetism in the films. Our results show that all the doped ZnO films are ferromagnetic at room temperature. A trace amount of additional Al doping has a significant effect on the improvement of ferromagnetic properties, and a maximum saturation magnetization of 73 emu/cm³ is obtained for (Al, N) co-doped ZnO films. The optical band gaps of ZnO films increase with the increasing Al doping content, which is owing to the combined effect of high carrier concentration and the Burstein Moss effect. The average transmittance of all ZnO films exceeds 80%. Our results confirm that appropriate electron doping can effectively enhance the magnetic moment in N implanted ZnO which may also apply to other ZnO systems with d⁰ magnetism.