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。     

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。     

不同择优取向的ZnO薄膜的制备

采用射频磁控溅射法在载玻片上制备了不同择优取向的ZnO薄膜。结果表明,溅射功率在100~380 W范围内制备的ZnO薄膜呈(101)择优取向性,当功率上升至550 W时,薄膜则为(100)取向;基片温度升高有利于(002)面的生长,当基片温度为250℃时,在溅射功率为200 W时即可制得(002)面择优取向的薄膜。热处理温度的提高有助于(100)和(101)面的择优取向,而对(002)面的取向不利。同时,该文对ZnO薄膜不同择优取向生长的机制进行了探讨。     

温度对飞秒激光沉积ZnO/Si薄膜的结构和性能的影响

通过飞秒脉冲激光(50 fs,800 nm,1 kHz,2 mJ)沉积技术在n型Si(100)单晶基片上制备了ZnO薄膜.详细研究了基片温度变化以及退火处理对ZnO薄膜的结构、表面形貌及光学性质的影响.X射线衍射(XRD)结果表明,不同温度下(20~350℃)生长的ZnO薄膜具有纤锌矿结构,并且呈c轴择优取向;当基片温度为80℃时,薄膜沿(002)晶面高度择优生长;当基片温度为500℃时薄膜沿(103)晶面择优生长,场发射扫描电子显微镜(FEEM)结果表明薄膜呈纳米晶结构,并观察到了ZnO的六方结构.进一步通过透射光谱的测量讨论了基片温度及退火处理对ZnO薄膜光学透射率的影响,结果表明退火后薄膜的透射率增大.     

射频磁控溅射ZnO薄膜的微结构与光学特性

研究了膜厚对ZnO薄膜微结构和光学性能的影响。采用射频磁控溅射法在单晶硅(111)和玻璃基片上制备了不同厚度的ZnO薄膜。通过X射线衍射、原子力显微镜和紫外可见光谱对薄膜进行了表征。结果表明薄膜结晶性能良好,在(002)晶面具有明显的c轴取向。随着薄膜厚度的增加,透射率下降,吸收边红移,禁带宽度逐渐减小。     

基于ZnO/SiO_2/Si多层结构瑞利波的特性研究

利用射频(RF)磁控溅射法沉积(002)ZnO薄膜和SiO_2薄膜于Si基底,研制(002)ZnO/IDT/SiO_2/Si结构的声表面波延迟线,并通过3D有限元法仿真分析该结构所激发的瑞利波的声学特性,如相速度、机电耦合系数k~2等。通过实验验证,发现二者吻合较好。分析了ZnO薄膜的厚度对瑞利波特性的影响发现,当ZnO厚为8μm时,k~2取得最大值(为3.88%)。同时,分析了(110)ZnO/IDT/SiO_2/Si结构所激发瑞利波的声学特性,结果显示,当ZnO薄膜的厚为8μm时,k~2取得最大值(为5.5%)。     

衬底温度对AlN/ZnO复合薄膜结构形貌的影响

采用直流反应磁控溅射法在ZnO/Si基片上制备了良好(002)(c轴)取向的AlN薄膜,利用XRD、AFM对不同衬底温度下制备的AlN薄膜的结构、形貌进行了分析表征.结果表明,在一定湿度范围内(450～650℃),随着衬底温度的升高,晶粒逐渐长大,沉积速率增大,表面粗糙度先减小后增大;AlN(002)择优取向呈改善趋势,取向度先增大后减小,600℃时达到最佳.     

FBAR用高质量AlN薄膜制备

采用直流磁控反应溅射法,在基片表面引入RF偏置,在Si(111)衬底上成功制备了(002)向AlN薄膜。使用高分辨率X射线衍射仪(XRD)来表征薄膜质量。当RF偏置从0 W变化到20 W时,XRD测试(002)摇摆曲线的半高宽有着显著的变化。当RF偏置为15 W时,AlN薄膜表现出了良好的(002)生长取向。实验结果表明,适当的RF偏置能够提高Al原子和N原子反应时的活性,促进AlN薄膜的(002)择优生长。该溅射方案应用于薄膜体声波谐振器(FBAR)谐振器工艺加工,成功制作了Q值为300,机电耦合系数为5%的FBAR样品。     

飞秒激光沉积ZnO/Si大面积均匀薄膜及其特性

利用飞秒脉冲激光沉积(PLD)法在Si(100)基片上制备大面积均匀的ZnO薄膜,通过激光束、靶材及衬底的运动使得所制备的薄膜均匀性面积大小不受限制。X射线衍射(XRD)结果显示,所制备的薄膜具有典型的六方纤锌矿结构,并沿(002)方向高度择优取向生长。场扫描电子显微镜(FESEM)显示,薄膜是沿垂直于衬底方向生长的六方柱状纳米晶,且膜厚均匀。紫外-可见光谱透射率显示,所制备的薄膜在380nm附近有一陡峭的吸收边,在可见光波段具有90%以上的透过率。光致发光(PL)光谱显示,薄膜在377nm处有一强而窄的紫外发射峰。实验结果表明,所制备的薄膜具有良好的结构及光学性能。     

薄膜厚度对ZnO∶Al透明导电膜性能的影响

铝掺杂的氧化锌(ZnO∶Al)透明导电膜是采用射频磁控溅射法在有机衬底(Polypro-pylene adipate, PPA)和Corning 7059玻璃上制备的.详细研究了薄膜的结构性质、光学和电学性质随薄膜厚度的变化关系.制备的ZnO∶Al薄膜具有(002)面的单一择优取向的多晶六角纤锌矿结构,性能优良的薄膜电阻率在两种衬底上分别为2.55×10-3Ω·cm和1.89×10-3Ω·cm,平均透射率达到了80%和85%.     

ZnO过渡层对BiFeO_3薄膜铁电性能的影响

采用溶胶–凝胶法,在Pt(111)/Ti/SiO2/Si(100)衬底上采用逐层退火工艺制备了BFO(BiFeO3)、ZnO/BFO和ZAO(掺铝氧化锌)/BFO薄膜,研究了ZnO、ZAO过渡层对BFO薄膜晶相以及铁电、漏电和介电性能的影响。结果表明:与BFO薄膜相比,ZnO/BFO薄膜的表面更加致密、平整,结晶性更好,双剩余极化强度(2Pr)有非常大的提高,漏电和介电性能也均有改善。ZAO/BFO薄膜的铁电性能比ZnO/BFO薄膜的铁电性能差,这与ZAO的导电性强于ZnO有关。     

sol-gel法制备ZnO薄膜压敏电阻

利用sol-gel法在镀有Au底电极的单晶硅片上,制备掺有Bi2O3、Co2O3、Cr2O3和MnO2的ZnO薄膜压敏电阻。薄膜由旋涂法制备,并在300℃下预处理、600℃退火。制得的ZnO薄膜结晶良好。膜厚约为1μm,ZnO薄膜压敏电阻的非线性系数为15.1,压敏电压为3.037 V,漏电流为43.25μA。     

适用SAW器件的ZnO/Ti/Si薄膜制备及缺陷分析

在Si(100)衬底和Ti/Si(100)衬底上分别制备了ZnO薄膜,探讨了Ti缓冲层对ZnO薄膜结构和缺陷的影响,利用X射线衍射(XRD)测试了ZnO薄膜的晶体结构及择优取向,利用原子力显微镜(AFM)观察ZnO薄膜的表面粗糙度(RMS),利用光致发光(PL)光谱检测了ZnO薄膜的缺陷,利用四探针法测试了ZnO薄膜的电阻率。结果表明,在Ti/Si(100)衬底上、衬底温度350℃的条件下,制备的ZnO薄膜表面光滑、缺陷少、电阻率高且具有高C轴取向。本文这一工作对于压电薄膜缺陷分析及高性能ZnO的声表面波(SAW)器件研制有重要意义。     

反应磁控溅射直接生长绒面结构ZnO:Al-TCO薄膜及其特性研究

利用反应磁控溅射技术,在玻璃衬底上直接生长获得了"弹坑状"绒面结构的ZnO:Al-TCO薄膜。通过梯度O2生长(GOG,gradual oxygen growth)方法改善ZnO薄膜的透过率和绒度特性,并且具有较好的电学性能。通过优化实验,GOG方法生长ZnO:Al薄膜(薄膜结构:11.0sccm/10R+9.5sccm/15R)的"弹坑状"特征尺寸为300～500nm,可见光范围透过率达到90%,方块电阻约为4.0Ω/□,电子迁移率为17.4cm2/V-1.s-1。大面积镀制的ZnO:Al具有良好的绒面结构和电学均匀性,可应用于光伏(PV)产业化推广应用。     

Surface planarization of ZnO thin film for optoelectronic applications

In this paper, surface morphology and optical properties are investigated to find the optimum microstructure of zinc oxide (ZnO) thin films deposited by radio frequency (RF) magnetron sputtering. To achieve a high transmittance and a low resistivity, we examined various film deposition conditions. The transmittance and surface morphology of ZnO thin films were measured by an ultraviolet (UV)-visible spectrometer and atomic force microscopy (AFM), respectively. In order to improve the surface quality of ZnO thin films, we performed chemical mechanical polishing (CMP) by change of process parameters, and compared the optical properties of polished ZnO thin films. As an experimental result, we were able to obtain good uniformity and improved transmittance efficiency by the CMP technique.     

LiNbO_3/ZnO:Al集成结构的外延生长及电性能研究

采用脉冲激光沉积(PLD)法在蓝宝石衬底上先后外延生长了ZnO:Al(ZAO)和LiNbO3(LN)薄膜。通过X射线衍射分析(XRD)可知二者之间的外延关系为:LN(001)//ZAO(001)、LN[110]//ZAO[110]、LN[100]//ZAO[120]。制备了Au/LN/ZAO和ZAO/LN/ZAO两种电容器结构,对其进行了电流-电压(J-E)测试和铁电(P-E)分析,结果表明:LN/ZAO集成结构具有整流作用,ZAO/LN/ZAO结构表现出较好的绝缘性能,所制备的LN薄膜在室温下的剩余极化强度(Pr)约为1×10–6C/cm2,温度的升高能够促进电畴的翻转,使Pr增加为3×10–6C/cm2。     

A study of the design of ZnO thin film pressure sensors

This study takes the first step in designing ZnO thin film pressure sensors with high operating temperatures. To fabricate the pressure sensors, ZnO thin films are deposited on SiO₂/(100)Si substrates to obtain structures similar to those of silicon-on-insulator. The optimal deposition parameters used to deposit the thin films are a full width at half maximum (FWHM) of 0.269, a c-axis-oriented structure near 100% and an average grain size of 321 Å. Here, to simplify the ZnO thin film pressure sensor system, a new parameter, the ZnO resistance, which changes with the change of pressure, is analysed. ZnO thin film fabricated under the optimal conditions can work as a pressure sensor and its response value, which is proportional to pressure, is greater than 8mΩ/psi. The relative pressure can be obtained from the difference between the response value before applying pressure and after. Further, a special characteristic of these ZnO pressure sensors is that the pressure can be read even during gas inlet.     

The effect of Mg and Al co-doping on the structural and photoelectric properties of ZnO thin film

Mg–Al co-doped ZnO thin films were prepared via radio-frequency reactive magnetron sputtering technique. X-ray diffraction investigation showed all the thin films with different Mg:Al ratio had hexagonal wurtzite structure. All the thin films showed (100) preferential orientation of ZnO. When Al concentration was kept constant but Mg concentration was increased, the grain size decreased at first and then increased. When Mg:Al ratio was 3:1, the grain size reached a maximum. Ultraviolet–visible spectra showed the thin films had a high average transmittance of 80% in the visible range. The optical band gaps of the thin films were obtained as follows: 3.31, 3.32, and 3.37 eV, corresponding to the Mg:Al ratio of 0:1, 1:1, and 3:1, respectively. Photoluminescence spectroscopy showed all the thin films had four main peaks located at 386, 410, 463, and 499 nm. The origin of blue peak is oxygen vacancy. When Mg concentration was kept constant but Al concentration was increased, I–V curve presented that for both of the heterojunctions the rectifying behavior was formed. The conductivity of Mg:Al=1:1 thin film is higher than that of Mg:Al=1:0 thin film. After illumination, light I–V curve deviated from rectifying character.     

改善玻璃衬底上ZnO薄膜特性的方法

利用磁控溅射法在玻璃衬底上淀积铝掺杂氧化锌(AZO)薄膜作为缓冲层,在其上制备了ZnO薄膜。重点研究了AZO薄膜作为缓冲层对玻璃衬底上ZnO薄膜特性的影响。扫描电子显微镜(SEM)图像和X射线衍射(XRD)图谱分析结果表明,玻璃衬底上加入厚度为1μm的AZO缓冲层后,提高了衬底材料和ZnO薄膜之间的晶格匹配程度,有助于增大ZnO薄膜晶粒尺寸,提高其(002)取向择优生长特性、薄膜结晶特性及晶格结构完整性。室温下的透射光谱结果表明玻璃/AZO和玻璃衬底上ZnO薄膜的透光特性没有显著不同。光致发光(PL)谱研究结果表明AZO缓冲层可以有效阻止衬底表面硅原子从ZnO薄膜中"俘获"氧原子,减少ZnO薄膜中的缺陷,改善ZnO薄膜的结晶质量。     

Effects of the ZnO buffer layer and Al proportion on AZO film properties

To evaluate the influence of the ZnO buffer layer and Al proportion on the properties of ZnO: Al (AZO)/ZnO bi-layer films, a series of AZO/ZnO films are deposited on the quartz substrates by electron beam evaporation. The X-ray diffraction measurement shows that the crystal quality of the films is improved with the increase of the film thickness. The electrical properties of the films are investigated. The carrier concentration and Hall mobility both increase with the increase of buffer layer thickness. However, the resistivity reaches the lowest at about 50 nm-thick buffer layer. The lowest resistivity and the maximum Hall mobility are both obtained at 1 wt% Al concentration. But the optical transmittance of all the films is greater than 80% regardless of the buffer layer thickness with Al concentration lower than 5 wt% in the visible region.