基于神经网络的AZO薄膜制备工艺参数的正交优化设计

采用磁控溅射法制备AZO薄膜,研究和讨论了溅射功率、溅射时间和溅射气压3个工艺参数对AZO薄膜光学和电学性能的影响。采用正交优化设计,对3个工艺参数进行优化,测量了透射率和电阻率,以此作为薄膜光电性能的评价指标,通过极差值分析确定了制备薄膜的最佳工艺参数。影响薄膜透射率的最主要因素为溅射气压;影响电阻率的最主要因素为溅射时间。获得制备高透射率低电阻率的AZO薄膜的最佳工艺组合方案为溅射功率为400W、溅射时间为1000s、溅射气压为1.0Pa。将反馈型(BP)神经网络应用于磁控溅射AZO薄膜光学性能(可见光区的平均透射率)和电学性能(电阻率)的研究。输入样品数据对神经网络进行训练,建立AZO薄膜光电性能随溅射参数变化的预测模型。     

In_2O_3：W薄膜的制备及光电性能研究

采用直流磁控溅射法制备了掺钨氧化铟（In2O3：W,IWO）薄膜,研究了制备工艺对薄膜表面形貌和光电性能的影响。结果表明薄膜的表面形貌与其光电性能有着紧密联系。氧分压显著影响薄膜的表面形貌进而对薄膜的光电性能产生影响,同时溅射时间的变化也显著影响薄膜的光电性能：随着氧分压以及溅射时间的升高,薄膜的电阻率均呈现先减小后增大的变化规律,在氧分压为2.4×10-1Pa条件下,制备样品的表面晶粒排布最细密,其电阻率达到6.3×10-4Ω.cm,载流子浓度为2.9×1020cm-3,载流子迁移率为34cm2/（V.s）,可见光平均透射率约为85%,近红外光平均透射率〉80%。     

辉光功率对柔性衬底ZnO:Al薄膜性能的影响

目前,磁控溅射制备Zn O:Al薄膜时的溅射压强较低,若氩气流量不稳或腔室排气口处气流扰动会对溅射压强产生较大影响,影响成膜质量。为提高溅射薄膜质量,采用直流磁控溅射技术,在较高溅射压强下,以不同辉光功率在柔性衬底聚酰亚胺上制备了Zn O:Al薄膜。采用紫外可见分光光度计、四探针测试仪、X射线衍射仪及扫描电镜测试薄膜性能,考察了辉光功率对薄膜光学特性、电学特性、薄膜结构和表面形貌的影响。结果表明:制备的薄膜均为六方纤锌矿结构,且有明显的c轴择优取向;随着辉光功率的增大,方块电阻先减小后增大,辉光功率为50 W时最小,为15.6Ω,晶粒尺寸先增大后减小;在辉光功率为50 W时,600~800 nm波长范围内薄膜的相对透射率达到最大值96%。     

基底结构对纳米铜膜光电性能影响

采用射频磁控溅射法,在涤纶机织布、纺粘非织造布、针织布、纤维膜表面沉积纳米铜薄膜,并用紫外-可见分光光度计与四探针测试仪测试样品透光和导电性能,用彩色摄像机观察溅射样品的表面形貌,用毛管流动孔隙仪测试不同基底孔隙大小及分布,并对结果进行比较分析。结果表明,基底布表面结构形貌与孔隙大小对样品光透射率、导电性能均产生影响。随基底布孔隙率的增加,样品透射率提高,导电性能减弱,针织布由于其松散的线圈结构使得其表面电阻难以测知。     

磁控溅射工艺对二氧化钒薄膜生长及场致相变性能的影响

为揭示VO2薄膜场致相变规律,指导氧化钒工业化规模制造与应用,使用磁控溅射直流溅射工艺在蓝宝石衬底上制备了VO2薄膜。对薄膜进行了XRD及SEM测试,分析了溅射氧分压、溅射温度及溅射压强对晶体组份、晶粒的生长趋势及晶体表面结构的影响规律。对VOx薄膜的场致相变特性进行了测试研究,分析了VOx薄膜的导电开关特性,总结了溅射氧氩比对其临界相变电场区间及电导率变化倍数的影响规律。得出结论,基片温度对成膜速度和晶粒大小及晶粒间隙有很大影响,溅射气压对薄膜表面晶体生长的均匀性影响显著,氧分压是影响薄膜组份的重要因素,氧氩比会影响薄膜的场致相变电导率变化倍数和临界相变电压区间。     

室温直流反应磁控溅射制备透明导电In_2O_3∶Mo薄膜

在室温条件下采用直流反应磁控溅射法制备了新型透明导电In2O3∶Mo薄膜。研究了溅射压强中氧气百分含量[P(O2)]为8.0%~18.0%时对薄膜光电特性以及表面形貌结构的影响。结果表明,薄膜的光电性能对溅射压强中P(O2)非常敏感。分析显示P(O2)决定了薄膜中的氧空位含量和载流子浓度,从而影响了薄膜的光电特性。原子力显微镜观察表明,适量的P(O2)条件下可以获得平均粗糙度为0.3 nm、颗粒均匀、表面平整的薄膜。室温制备的IMO薄膜在可见光区域的平均透射率(含玻璃基底)高达82.1%,电阻率低至5.9×10-4Ω.cm。     

室温直流反应磁控溅射制备透明导电In2O3:Mo薄膜

在室温条件下采用直流反应磁控溅射法制备了新型透明导电In2O3:Mo薄膜.研究了溅射压强中氧气百分含量[P(O2)]为8.0%～18.0%时对薄膜光电特性以及表面形貌结构的影响.结果表明,薄膜的光电性能对溅射压强中P(O2)非常敏感.分析显示P(O2)决定了薄膜中的氧空位含量和载流子浓度,从而影响了薄膜的光电特性.原子力显微镜观察表明,适量的P(O2)条件下可以获得平均粗糙度为0.3 nm、颗粒均匀、表面平整的薄膜.室温制备的IMO薄膜在可见光区域的平均透射率(含玻璃基底)高达82.1%,电阻率低至5.9×10-4 Ω·cm.     

Nb-Zn-Sn-O非晶薄膜的生长与性能

采用射频磁控溅射技术,成功制备出能用作薄膜晶体管(TFT)沟道层的非晶态Nb-ZnSn-O(NZTO)薄膜。研究了溅射压强、退火处理对NZTO薄膜的材料结构、电学和光学性能的影响,并在溅射功率为120W、溅射压强为0.6Pa且在400℃温度下退火2h后,制备出了电子迁移率达5.5cm2v-1s-1、载流子浓度在1017以下且可见光透射率为80%以上的薄膜。     

基体温度对中频磁控溅射制备的氧化锌镓薄膜性能的影响

利用中频磁控溅射方法,溅射Ga2O3含量为5.7 wt.%的氧化锌镓陶瓷靶材,在不同的基体温度下制备了ZGO薄膜。研究了基体温度对ZGO薄膜的晶体结构、电学和光学性能的影响。结果表明:基体温度对薄膜的晶体结构、近红外反射率和透射率曲线以及薄膜的导电性能有较大影响。当基体温度为400℃,溅射功率密度为2.93 W/cm2,氩气压力为0.5 Pa时,薄膜的电阻率低达4.5×10-4Ω.cm,方块电阻为13Ω,平均可见光(λ=400 nm~800 nm)透射率高于90%。     

磁控溅射W-T-iN/MoS_2薄膜及其摩擦学性能研究

采用W靶、Ti靶及MoS2靶,先制备W-T-iN薄膜,然后再在其上面沉积MoS2纳米薄膜得到W-T-iN/MoS2纳米双层薄膜,通过多次实验得到溅射W-T-iN/MoS2薄膜的最佳工艺如下:溅射气压1.0 Pa,靶基距为100 mm,溅射功率为:W靶,Ti靶均为200W,MoS2靶为150 W;制备W-T-iN薄膜溅射时间为1 h,样品台加热600℃;制备MoS2纳米层时间为0.5 h。使用X射线衍射仪,扫描电子显微镜对薄膜的成分和结构进行分析。采用纳米压痕测试系统测试薄膜的纳米硬度和弹性模量,采用VEECOWYKONT1100非接触光学表面轮廓仪测试薄膜的表面及磨痕粗糙度;UMT-3摩擦磨损试验机在大气、室温、无润滑条件下对薄膜摩擦磨损性能分析,结果表明:在大气环境中,W-T-iN/MoS2薄膜摩擦性能要优于纯W-T-iN薄膜。     

溅射功率对ZnO:Al薄膜光电性能的影响

采用射频磁控溅射工艺,以Al掺杂ZnO(ZAO)陶瓷靶为靶材在石英玻璃基片上制备出具有优良光电性能的ZAO透明导电薄膜,研究了溅射功率对薄膜光电性能的影响。在不同溅射功率条件下制备的ZAO薄膜具有很好的c轴择优取向。较大功率溅射有利于薄膜晶粒尺寸的增大、电阻率降低。ZAO薄膜在可见光区的透过率平均值高达90%以上,受溅射功率影响不大。在340nm-420nm波长附近ZAO薄膜透过率急剧下降,呈现明显的紫外吸收边;高的溅射功率提高了ZAO薄膜的光学带隙宽度。     

氢化及沉积温度对掺铝ZnO透明导电薄膜性能影响

采用射频磁控溅射方法在玻璃衬底上制备了掺铝ZnO透明导电薄膜(AZO)。为了降低AZO薄膜的电阻率, 采用在溅射气氛中通入一定比例H₂的方法对AZO薄膜进行氢化处理, 并研究了溅射气氛中H₂含量及衬底温度对AZO薄膜氢化效果的影响。结果表明: 在低温条件下, 氢化处理能有效降低AZO薄膜的电阻率; 在衬底温度为100℃的低温条件下, 通过调节溅射气氛中H₂的比例, 制备了电阻率为6.0×10^-4 Ω·cm的高质量氢化AZO薄膜, 该电阻值低于同等条件下未氢化AZO薄膜电阻值的1/3; 但随着衬底温度的升高, 氢化处理对薄膜电学性能的改善效果逐渐减弱。     

交流磁控溅射制备ZAO薄膜工艺参数的研究

对于交流磁控溅射氧化锌铝陶瓷靶材制备ZAO薄膜,研究了氧流量、基体温度、靶电流密度、铝的掺杂量、本底真空压力和工作气体压力对ZAO薄膜电学性能的影响规律,优化了工艺参数,为工业化生产提供了实验依据.     

磁控溅射技术制备Al_2O_3掺杂ZnO透明导电膜的性能

以纯度为99.9%的98%(质量分数)ZnO、2%(质量分数)Al_2O_3陶瓷靶为溅射靶材,采用射频磁控溅射法在玻璃衬底上制备了Al_2O_3掺杂的ZnO薄膜。采用X射线衍射仪、扫描电子显微镜、紫外可见光谱仪等方法测试和分析了不同衬底温度、溅射偏压以及退火工艺对ZAO薄膜形貌结构、光电学性能的影响。结果表明,在衬底温度200℃、溅射时间30min、负偏压60V、退火温度300℃时制得的薄膜的可见光透过率为81%,最低电阻率为9.2×10~(-1)Ω·cm。     

不同铝掺杂量ZnO薄膜性能的研究

以铝掺杂质量分数为1%、2%、3%的Zn/Al合金为靶材,采用直流反应磁控溅射技术在玻璃衬底上制备了不同铝含量ZnO:Al(AZO)透明导电薄膜。研究了衬底温度对AZO薄膜电学性能的影响;同时,研究铝掺杂量不同、电阻率相同的AZO薄膜的载流子浓度与迁移率的关系。结果表明:随着Al掺杂量的增加,薄膜最佳性能(透过率90%,电阻率6×10-4Ω·cm左右)时的衬底温度值会降低;电阻率相同的样品,1%铝掺杂的薄膜迁移率和透光率均高于2%铝掺杂薄膜的。     

Preparation of Al-doped ZnO transparent electrodes suitable for thin-film solar cell applications by various types of magnetron sputtering depositions

In order to determine the influence of different types of magnetron sputtering (MS) depositions on the characteristics of Al-doped ZnO (AZO) thin films appropriate for applications as transparent electrodes in thin-film solar cells, transparent conducting AZO thin films were prepared on glass substrates at 200 °C by direct current (dc) magnetron sputtering (dc-MS), radio frequency (rf)-MS and rf power superimposed dc-MS (rf + dc-MS) depositions using an MS apparatus with the same AZO target. AZO thin films prepared by an rf + dc-MS deposition exhibited both a higher deposition rate than that found with rf-MS depositions and a lower resistivity or higher Hall mobility than those found with dc-MS. The lower dc sputter voltage featured in rf-MS and rf ± dc-MS depositions, producing smoother surface morphology and better crystallinity than obtained with dc-MS depositions. The light scattering characteristics of surface-textured AZO thin films prepared by various types of MS depositions were evaluated by observing the surface texture and measuring the optical transmittance and the diffusive component; wet-chemical etching of the thin film surface was performed in a 0.1% HCl solution. The obtainable haze property in the range from visible to near infrared in AZO films prepared by an rf + dc-MS deposition was markedly better than that obtained with dc-MS depositions.     

ZnO缓冲层上低温生长Al掺杂的ZnO薄膜

采用射频磁控溅射法在ZnO缓冲层上制备了不同Al掺杂量的ZnO（AZO）薄膜。利用X射线衍射（XRD）、扫描电子显微镜（SEM）和光致发光（PL）等表征技术,研究了AZO薄膜的微观结构、表面形貌和发光特性。结果表明,随着Al掺杂量的增加,ZnO薄膜的择优取向性发生了改变,且当Al的掺杂量为0.81%（原子分数）时,（002）衍射峰与其它衍射峰强度的比值达到最大,表明适合的Al掺杂使ZnO薄膜的择优取向性得到了改善。在可见光范围内薄膜的平均透过率超过70%。通过对样品光致发光（PL）谱的研究,发现所有样品出现了3个发光峰,分别对应于以444nm（2.80eV）、483nm（2.57eV）为中心的蓝光发光峰和以521nm（2.38eV）为中心较弱的绿光峰。并对样品的发光机理进行了详细的探讨。     

Improvements of spatial resistivity distribution in transparent conducting Al-doped ZnO thin films deposited by DC magnetron sputtering

The relationship between two techniques developed for improving the resistivity distribution on the substrate surface in transparent conducting Al-doped ZnO (AZO) thin films prepared at a temperature of 200 °C by dc magnetron sputtering depositions (dc-MSD) using various sintered AZO targets has been investigated. One improvement method superimposes an rf component onto the dc-MSD (rf + dc-MSD). The other improvement method uses conventional dc-MSD with a low resistivity AZO target prepared under optimized conditions. An improvement of resistivity distribution resulted from a decrease in the resistivity of targets used in the preparation of AZO thin films by dc-MSD either with or without superimposing rf power. However, the resistivity distribution of AZO thin films resulting from depositions using rf-superimposed dc-MSD with lower-resistivity targets was not significantly improved over that of AZO thin films prepared by conventional dc-MSD using targets with the same low resistivities. The use of rf superimposition only resulted in improved resistivity distribution in thin films when the AZO targets had a resistivity higher than around 1 × 10^− 3 Ω cm. It should be noted that sintered AZO targets optimized for the preparation of AZO thin films with lower resistivity as well as more uniform resistivity distribution on the substrate surface tended to exhibit a lower resistivity.     

Comparative study of resistivity characteristics between transparent conducting AZO and GZO thin films for use at high temperatures

This paper compares in detail the resistivity behavior of transparent conducting Al-doped and Ga-doped ZnO (AZO and GZO) thin films for use in an air environment at high temperatures. AZO and GZO thin films with thicknesses in the range from approximately 30 to 100 nm were prepared on glass substrates at a temperature of 200 °C by rf superimposed dc or conventional dc magnetron sputtering deposition, pulsed laser deposition or vacuum arc plasma evaporation techniques. In heat-resistance tests, the resistivity was measured both before and after heat tests for 30 min in air at a temperature up to 400 °C. The resistivity stability of AZO thin films was found to be always lower than that of GZO thin films prepared with the same thickness under the same deposition conditions, regardless of the deposition technique. However, the resistivity of all AZO and GZO thin films prepared with a thickness above approximately 100 nm was stable when heat tested at a temperature up to approximately 250 °C. It was found that the resistivity stability in both GZO and AZO thin films is dominated by different mechanisms determined by whether the thickness is below or above approximately 50 nm. With thicknesses above approximately 100 nm, the increase in resistivity found in GZO and AZO films after heat testing at a temperature up to 400 °C exhibited different characteristics that resulted from a variation in the behavior of Hall mobility.     

Electrical mechanism analysis of Al2O3 doped zinc oxide thin films deposited by rotating cylindrical DC magnetron sputtering

Cost efficient and large area deposition of superior quality Al₂O₃ doped zinc oxide (AZO) films is instrumental in many of its applications, including solar cell fabrication due to its numerous advantages over indium tin oxide (ITO) films. In this study, AZO films were prepared by a highly efficient rotating cylindrical direct current (DC) magnetron sputtering system using an AZO target, which has a target material utilization above 80%, on glass substrates in argon (Ar) ambient. A detailed analysis on the electrical, optical, and structural characteristics of AZO thin films was performed for the solar cell, as well as display applications. The properties of films were found to critically depend on deposition parameters, such as sputtering power, substrate temperature, working pressure, and film thickness. A low resistivity of ~ 5.5 × 10^− 4 Ω cm was obtained for films deposited at 2 kW, keeping the pressure, substrate temperature and thickness constant at 3 mTorr, 230 °C and ~ 1000 nm respectively. This was due to an increase in carrier mobility and large grain size. Mobility is found to be controlled by ionized impurity scattering within the grains, since the mean free path of carriers is much smaller than the grain size of the films. The AZO films showed a high transparency of ~ 90% in the long wavelength region. Our results offer a cost-efficient AZO film deposition method that can fabricate films with significant low resistivity and high transmittance that can be applied in thin-film solar cells, as well as thin film transistor (TFT) and non-volatile memory (NVM).