Mo电极形貌对AlN薄膜择优取向生长的影响

采用射频磁控溅射方法在不同形貌的Mo电极上制备了(002)择优取向的AlN薄膜。采用XRD、FESEM表征了Mo电极及AlN薄膜的结构、表面形貌及择优取向。结果表明,Mo电极的形貌影响AlN薄膜的择优取向生长,在较高溅射气压下沉积的Mo电极晶粒细小、分布均匀,有助于AlN薄膜(002)择优取向生长。     

SiO_2/Si上直流磁控反应溅射制备AlN薄膜

利用正交设计分析了直流磁控溅射中溅射气压,衬底温度和N2浓度对SiO2/Si衬底上制备的AlN薄膜的(002)择优取向的影响水平。利用X-射线衍射(XRD)、场发射扫描电镜(FESEM)、原子力显微镜(AFM)对薄膜的晶向和表面形貌进行了分析,得到制备高度择优取向的AlN薄膜的最佳期望条件:衬底温度为250℃,溅射气压为2Pa,N2浓度为75%;并得出了氮气浓度对薄膜的(002)择优取向的影响较大。具有择优取向的AlN薄膜的折射率约为2.06。     

射频反应磁控溅射制备AlN多晶薄膜及其择优取向研究

采用RF反应磁控溅射在Si(111)基片上制备了多晶AlN薄膜,研究了工作气压对AlN薄膜晶面择优取向的影响。利用台阶仪、X射线衍射(XRD)、红外吸收光谱(FTIR)对AlN薄膜的沉积速率、晶体结构、化学结构及成分进行了表征。结果表明:工作气压对AlN薄膜晶面择优取向具有十分显著的影响,当工作气压低于0.6 Pa时,薄膜呈现(002)晶面择优取向;当气压增加到1 Pa时,AlN薄膜呈现(100),(002)混合晶面取向;当工作气压为1.5 Pa时,(002)晶面衍射峰消失,薄膜呈现(100)晶面择优取向。根据分析结果,提出了工作气压对AlN薄膜择优取向的影响机制,其次,在AlN薄膜的FTIR光谱中,Al-N键振动在波数为678 cm-1处有强烈的吸收峰,Al-N振动吸收峰包含A1(TO)模式以及E1(TO)模式,分别位于612,672cm-1附近,A1(TO)模式与E1(TO)模式振动吸收峰的积分面积之比与AlN薄膜的择优取向有关。结果显示FTIR技术可以作为XRD的补充手段,用于表征多晶AlN薄膜的择优取向。     

AlN薄膜的KrF准分子脉冲激光沉积

研究了采用脉冲激光沉积(PLD)技术在Si(100)衬底上AlN薄膜的制备及其性质。结果表明,衬底温度从室温到800℃的范围内,所得到的AlN薄膜为(002)择优取向的纤锌矿结构。随着衬底温度的升高,AlN薄膜从纳米晶结构转为多晶结构,同时表面微粗糙度上升。AlN晶粒呈柱状生长机制。     

射频反应溅射制备倾斜AlN薄膜

采用射频反应磁控溅射方法,通过旋转转盘,使衬底与靶材水平偏离一定角度,制备了C轴择优取向的倾斜AlN薄膜。用XRD分析了不同偏转角度下制备的AlN薄膜的择优取向度,用场发射扫描电镜(FE-SEM)观察了薄膜的截面形貌,并初步讨论了倾斜AlN薄膜的生长机理。分析和测试结果表明,当转盘旋转角度为10°时,AlN薄膜柱状晶倾斜最明显,倾斜角度可达25°。     

AlN压电薄膜研究进展

介绍了AlN压电薄膜的研究现状,着重突出了AlN薄膜的制备方法、择优取向结构及表面形貌等方面的研究,尤其对脉冲激光沉积工艺(PLD)镀膜的基本原理和过程、分别采用周期价键链(PBC)理论和断键模型对薄膜晶面择优取向机理的分析作了较为详细的探讨.最后简单讨论了AlN压电薄膜研究的发展趋势.     

AIN压电薄膜研究进展

介绍了AlN压电薄膜的研究现状,着重突出了AlN薄膜的制备方法、择优取向结构及表面形貌等方面的研究,尤其对脉冲激光沉积工艺(PLD)镀膜的基本原理和过程、分别釆用周期价键链(PBC)理论和断键模型对薄膜晶面择优取向机理的分析作了较为详细的探讨。最后简单讨论了AlN压电薄膜研究的发展趋势。     

溅射时间对Mo薄膜结晶取向的影响

采用直流磁控溅射法在SLG衬底上沉积Mo薄膜,并用XRD、SEM、四探针等对薄膜进行表征,研究了沉积时间对薄膜晶体结构、表面形貌以及电学性能的影响。研究发现,沉积时间能够调节Mo薄膜的择优取向。溅射时间较短(5～10min)时,沉积的Mo薄膜呈(110)择优取向。溅射时间超过15min后,薄膜呈现(211)取向,且(211)晶面择优程度随沉积时间的增加而提高。随着择优取向的改变,薄膜的表面形貌由三角形颗粒变为长条形颗粒,电阻率也发生相应变化,由3.92×10-5Ω·cm增加到4.27×10-5Ω·cm再降低,对应薄膜生长的晶带模型由晶带T型组织变为晶带2组织。     

中频磁控反应溅射制备c轴择优取向AlN薄膜

通过中频磁控反应溅射,在Si(100)衬底上沉积AlN薄膜,并用X射线衍射、扫描电子显微镜和Raman光谱表征AlN薄膜的微观特征.实验中,研究了氮分压、靶基距、溅射功率对AlN薄膜质量的影响,并优化参数制备高质量的c轴取向的AlN薄膜.结果表明,提高溅射功率、降低靶基距以及降低氮分压,有利于c轴择优取向AlN的生长.在优化条件下制备的AlN薄膜具有高度c轴取向,(002)摇摆曲线的半高宽为5.7°,Raman光谱E2(high)声子峰的FWHM为13.8cm-1.     

脉冲激光沉积氮化铝薄膜的电学性能研究

采用脉冲激光沉积(PLD)技术在硅片上合成了AlN薄膜.X射线衍射(XRD)结果证实制备的AlN薄膜具有(002)择优取向的六方纤锌矿晶体结构,并且结晶质量随Si衬底温度的提高而改善.电流-电压(I-V)、电容-电压(C-V)、极化曲线结果表明室温生长的AlN薄膜的击穿场强约2.5MV/cm,同时呈现明显的极化现象(类铁电),对应矫顽场强为150kV/cm,剩余极化为0.002C/m2.晶态AlN存在较强的自发极化,薄膜中可动电荷密度高,据此提出了动态电荷模型,指出较大的AlN薄膜极化回线是由于可动电荷在电场中的再分布形成的,因而有别于铁电材料.     

A Study of AlN Films Prepared by Arc Ion Plating

Hexagonal AlN films have been obtained by arc ion plating at different negative biases ,X-ray diffraction and scanning electron microscopy results show that AlN films with smooth surfaces and (002) preferred orientation are obtained at low biases ,whereas those with coarse surfaces and (100) preferred orientation are obtained at high biases,The formation mechanism of AlN is analyzed and the experiment results are discussed,The effect of bias on adhesion strength has also been examined.     

Combination of e-beam lithography and of high velocity AIN/diamond-layered structure for SAW filters in X band

In this work, we report on the fabrication results of surface acoustic wave (SAW) devices operating at frequencies up to 8 GHz. In previous work, we have shown that high acoustic velocities (9 to 12 km/s) are obtained from the layered AIN/diamond structure. The interdigital transducers (IDTs) made of aluminium with resolutions up to 250 nm were successfully patterned on AIN/diamond-layered structures with an adapted technological process. The uniformity and periodicity of IDTs were confirmed by field emission scanning electron microscopy and atomic force microscopy analyses. A highly oriented (002) piezoelectric aluminum nitride thin film was deposited on the nucleation side of the CVD diamond by magnetron sputtering technique. The X-ray diffraction effectuated on the AIN/diamond-layered structure exhibits high intensity peaks related to the (002) AIN and (111) diamond orientations. According to the calculated dispersion curves of velocity and the electromechanical coupling coefficient (K2), the AIN layer thickness was chosen in order to combine high velocity and high K2. Experimental data extracted from the fabricated SAW devices match with theoretical values quite well.     

Electrical,morphological and structural properties of RF magnetron sputtered Mo thin films for application in thin film photovoltaic solar cells

Molybdenum (Mo) thin films were deposited using radio frequency magnetron sputtering, for application as a metal back contact material in “substrate configuration” thin film solar cells. The variations of the electrical, morphological, and structural properties of the deposited films with sputtering pressure, sputtering power and post-deposition annealing were determined. The electrical conductivity of the Mo films was found to increase with decreasing sputtering pressure and increasing sputtering power. X-ray diffraction data showed that all the films had a (110) preferred orientation that became less pronounced at higher sputtering power while being relatively insensitive to process pressure. The lattice stress within the films changed from tensile to compressive with increasing sputtering power and the tensile stress increased with increasing sputtering pressure. The surface morphology of the films changed from pyramids to cigar-shaped grains for a sputtering power between 100 and 200 W, remaining largely unchanged at higher power. These grains were also observed to decrease in size with increasing sputtering pressure. Annealing the films was found to affect the resistivity and stress of the films. The resistivity increased due to the presence of residual oxygen and the stress changed from tensile to compressive. The annealing step was not found to affect the crystallisation and grain growth of the Mo films.     

Structure and electrical properties of Mo back contact for Cu(In, Ga)Se2 solar cells

Mo layers were deposited on soda lime glass via DC magnetron sputtering of a Mo target in a pure Ar atmosphere. The structure and electrical resistivity of Mo thin films, which may be varied by controlling the sputtering pressure, were investigated. The films showed (110) preferred orientation regardless of the working pressure. Films sputtered at low working pressure had low resistivity but adhered poorly to glass. A study of the deposition of a Mo bilayer was conducted. Optimum properties of the Mo bilayer were obtained when the bottom layer was deposited at 10 mtorr and the top layer was deposited at 2.5 mtorr. The extremely low resistivity of 6.57 μΩ-cm was obtained, which is better than other literatures. A Cu(In, Ga)Se₂ cell fabricated on a Mo film sputtered under optimized conditions showed 10.40% efficiency.     

Thickness effect on properties of titanium film deposited by d.c. magnetron sputtering and electron beam evaporation techniques

This paper reports effect of thickness on the properties of titanium (Ti) film deposited on Si/SiO₂ (100) substrate using two different methods: d.c. magnetron sputtering and electron beam (e-beam) evaporation technique. The structural and morphological characterization of Ti film were performed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). XRD pattern revealed that the films deposited using d.c. magnetron sputtering have HCP symmetry with preferred orientation along (002) plane, while those deposited with e-beam evaporation possessed fcc symmetry with preferred orientation along (200) plane. The presence of metallic Ti was also confirmed by XPS analysis. FESEM images depicted that the finite sized grains were uniformly distributed on the surface and AFM micrographs revealed roughness of the film. The electrical resistivity measured using four-point probe showed that the film deposited using d.c. magnetron sputtering has lower resistivity of ～13 μΩcm than the film deposited using e-beam evaporation technique, i.e. ～60 μΩcm. The hardness of Ti films deposited using d.c. magnetron sputtering has lower value (～7·9 GPa) than the film deposited using e-beam technique (～9·4 GPa).     

CIGS薄膜太阳能电池用Mo背电极的制备与结构性能研究

利用磁控溅射技术在Soda-lime玻璃衬底上沉积CIGS薄膜太阳能电池用金属Mo背电极薄膜,并研究了Mo靶功率、基片脉冲宽度以及预清洗时间对Mo薄膜的相结构、形貌及电阻率的影响。结果表明,沉积的Mo薄膜均沿(110)晶面呈柱状择优生长;增大Mo靶溅射功率可以促进薄膜晶粒长大、提高薄膜的致密性、降低电阻率;合适的基片脉冲电压脉宽促进了晶核的形成、长大并有助于沉积过程中Mo晶粒长大,进而降低薄膜电阻率;通过延长预清洗时间可获得致密性好、电阻率低的Mo薄膜,所获得的Mo薄膜最低电阻率为3.5×10-5Ω.cm。     

磁控溅射制备大面积ZnO薄膜性能的研究

通过磁控溅射氧化锌陶瓷靶材的方法在玻璃基片上制备ZnO薄膜,研究了溅射功率、溅射气压以及基片温度对ZnO薄膜相结构、禁带宽度及光学性能的影响.使用X射线衍射仪(XRD)分析了薄膜相结构,使用台阶仪测试薄膜厚度,采用薄膜测试仪测试薄膜的透过率,采用扫描电镜(SEM)观察薄膜表面形貌.结果表明:不同制备条件下均形成具有(0...     

Influence of the seed layer on structural and electro-acoustic properties of sputter-deposited AlN resonators

The growth of high-quality AlN films has been studied by reactive sputtering onto Mo electrodes with Ni, Ti, and TiW seed layers and subsequent integration into thin film bulk acoustic wave resonators. The crystalline structure and morphology of the Mo and c-axis oriented AlN films were found to vary strongly with seed layer material and thickness. The smoothest Mo electrodes were obtained on thin Ti films. Reactive sputtering of AlN on top of these optimized electrodes resulted in a dense columnar grain structure with a well-aligned (002) crystal orientation and good electro-acoustic properties, including an effective coupling coefficient of 6.89% and quality factor above 1000.     

PZT/ZnO薄膜制备及其结构特性研究

利用固相反应制备的ZnO-Li_(2.2%)陶瓷靶和RF射频磁控溅射技术在Si(100)基片上制备了高度c轴择优取向的ZnO薄膜,XRD和电性能分析表明掺杂Li离子改善了ZnO靶材的结构和性能,同时研究了不同RF溅射温度对ZnO薄膜结构与取向的影响;然后采用sol-gel前驱单体薄膜制备方法,以ZnO为过渡层淀积PZT薄膜,探讨高度c轴(002)择优取向ZnO薄膜对PZT薄膜结构与性能的影响,实验发现在PZT/ZnO异质结构中,致密、均匀和高度c轴择优取向的ZnO可作为晶核,促进PZT钙钛矿结构转化、晶粒(110)择优取向生长,相应降低PZT薄膜的退火温度.     

溅射工艺对BST薄膜取向行为的影响

采用射频磁控溅射法在Si(100)衬底上沉积了Ba0.65Sr0.35TiO3薄膜.借助XRD、AFM和SEM研究了衬底温度、退火温度、溅射气压等不同的溅射参数对Ba0.65Sr0.35TiO3薄膜的晶化行为和显微结构的影响.在室温下沉积并未经退火处理的Ba0.65Sr0.35TiO3 薄膜是无定形态,在较高温度下沉积的薄膜晶化相对较好;随着在氧气气氛中退火温度的升高,X射线衍射峰的半峰宽变窄,衍射峰强度增强;在0.37～1.2Pa气压下沉积的Ba0.65Sr0.35TiO3薄膜有(110)和(200)主衍射峰,且其强度随溅射气压的增加而增强;当溅射气压继续升到3.9Pa,(110)和(200)衍射峰明显增强,说明Ba0.65Sr0.35TiO3 薄膜具有(110) (200)择优取向.AFM和SEM结果显示薄膜晶粒细小均匀、结构致密、表面平整,且无裂纹、无孔洞.分析结果显示优化工艺参数制备的Ba0.65Sr0.35TiO3 薄膜是用以制备非致冷红外探测器的优质材料.