α－Al_2O_3衬底上生长的GaN膜的光学性质

采用金属有机化学气相淀积（ＭＯＣＶＤ）方法生长了α－Ａｌ２Ｏ３衬底上外延的高质量的单晶ＧａＮ薄膜。Ｘ射线衍射光谱与喇曼散射光谱表征了ＧａＮ外延薄膜的单晶结构和单晶质量。透射光谱和光调制反射光谱定出了六角单晶ＧａＮ薄膜的直接带隙宽度和光学参数。     

常压MOCVD制备MgO薄膜的研究

本文首次报道用常压金属有机化学气相沉积（ＡＰ－ＭＯＣＶＤ）在Ｓｉ（１００），ＳｉＯ２／Ｓｉ（１００）和Ｐｔ／Ｓｉ（１００）衬底上外延高质量的ＭｇＯ薄膜。研究了衬底温度与薄膜的取向性关系和ＭｇＯ薄膜的潮解特性。高纯ｍａｇｎｅｓｉｕｍａｃｅｔｙｌａｃｅｔｏｎａｔｅ［ｂｉｓ（２，４－ｐｅｎｔａｎｅｔａｎｅ－ｄｉｏｎｏ）ｍａｇｎｅｓｉｕｍ］［Ｍｇ（ＣＨ２ＣＯＣＨ２ＣＯＣＨ３）２］作为金属有机源，扫描电镜（ＳＥＭ），透射电镜（ＴＥＭ）和Ｘ－ＲＡＹ衍射实验显示，在较低的衬底温度（～４８０℃）下一次淀积成单晶膜。薄膜均匀，致密，结晶性和取向性很好，衬底温度（Ｔｓ）在４００℃到６８０℃之间，在Ｓｉ（１００）衬底上生长的ＭｇＯ薄膜都具有［１００］取向，在Ｓｉ（１００）、ＳｉＯ２／Ｓｉ（１００）和Ｐｔ／Ｓｉ（１００）衬底上生长的ＭｇＯ薄膜也都具有［１００］取向。     

Mo／α—Al2O3界面的二次离子质谱研究

采用电子束蒸发方法，在２００℃的抛光（１１０２）取向的蓝宝石（α－Ａｌ２Ｏ３）单晶衬底上淀积厚度为３００ｎｍ的Ｍｏ膜。经８７０℃下不同真空退火时间处理后，运用ＭＣｓ＾＋－ＳＩＭＳ技术进行了深度剖析，并结合ＸＲＤ物相分析，对Ｍｏ／Ａｌ２Ｏ３界面问题进行了探讨。结果表明，在Ｍｏ／Ａｌ２Ｏ３界面处存在原子相互扩散形成的过渡层。退火处理后，过渡层展宽，有ＭｏＯ２生成。延长退火时间，过渡层变化不大。     

应用铟源的反应蒸发制备In2O3透明导电膜

本工作说明，在低压氧气氛中。应用铟源的反应蒸发很容易淀积高质量的Ｉｎ２Ｏ３透明导电膜．旦然没有使用锡杂质，但所得膜的性能可以和最好的掺锡的Ｉｎ２Ｏ３膜相比．膜电阻率达２～３×１０￣４Ω·ｃｍ，可见光透过率超过９０％，并且膜生长速率高达２１９／ｍｉｎ．文章对成膜过程作了分析，报道了膜的最佳淀积条件，对由于偏离最佳淀积参数而导致的异常膜的形成机制也进行了讨论．     

c取向YBa2Cu3O7—δ超导外延膜进脱氧过程

用电阻法测量了ＹＢａ２Ｃｕ３Ｏ７－δｃ取向外延膜进脱氧过程,结果表明在氧含量变化较小的情况下,进氧、脱氧速率相近,用Ｘ射线衍射方法证明了ＹＢａ２ＣＵ３Ｏ７－δｃ取向外延膜电阻率与氧含量成指数关系,获得氧化学扩散激活能久为０．９ｅｖ。     

α—Al2O3衬底上生长的GaN膜的光学性质

采用金属有机化学气相淀积方法生长了α－Ａｌ２Ｏ３衬底上外延的高质量的单晶ＧａＮ薄膜。Ｘ射线衍射光谱与喇曼散射光谱表征了ＧａＮ外延薄膜的单晶结构和单晶质量。透射光谱和光调制反射光谱定出了六角单晶ＧａＮ薄膜的直接带隙宽度和光学参数。     

聚合物复合材料薄膜极化及性能的研究

制取了ＰｂＴｉＯ３纳米微晶与高透明度的聚合物ＰＥＫ－Ｃ组成的复合材料薄膜,从介电性和有效场理论出发,对极化条件的优化进行了研究,通过测量极化后的复合材料的Ｘ－ｒａｙ衍射,得知ＰｂＴｉＯ３微晶的ｃ轴取向度达到６８％,测量了３８０ｎｍ－９００ｎｍ的透过光谱,估算了极化前后光学带隙能量。     

热丝法低温生长硅上单晶碳化硅薄膜

提出了热丝化学气相淀积法，在低温（６００－７５０℃）下成功地生长出硅上单晶碳化硅薄膜，Ｘ光衍射谱、喇曼光谱证实了外延膜的单晶结构，光致发光测量证明外延ＳｉＣ材料室温下可稳定发射可见光。     

SrTiO3（110）上水热法外延生长PbTiO3薄膜

利用低温水热合成工艺，在一定浓度皆Ｐｂ（ＮＯ）３，ＴｉＣｌｒ的混合强碱性水溶液中，和在（１２０℃，０．２５ＭＰａ）的水热反应条件下，首次成功地在ＳｒＴｅＯ３单昌衬底上生长出具有面积构的ＰｂＴｉＯ３外延薄膜。     

溶胶—凝胶法制备纯PbTiO3超细粉的研究

以金属醇盐和无机盐为原料，用溶胶－凝胶法制备合成了粒径小于５０ｎｍ的纯ＰｂＴｉＯ３超细粉，探讨了溶胶－凝胶过程反应机理，并对制备过程中的一些主要因素如ｐＨ值、溶液浓度和温度等进行了讨论，采用热分析、Ｘ－Ｒａｙ衍射分析和ＴＥＭ等测试手段对ＰｂＴｉＯ３超细粉进行了分析。     

Optical waveguiding in epitaxial PbTiO(3) thin films

Epitaxial lead titanate (PbTiO(3)) thin films on SrTiO(3) (100) substrate were grown in situ by radio-frequency sputtering for optical waveguiding applications. The crystalline quality of the PbTiO(3) films deposited at 550 degrees C has been investigated through x-ray diffraction analysis. It indicates that thin films are completely c-axis oriented (rocking curve FWHM of 0.2 degrees for the 001 reflection). The transmission spectrum method has been used to measure the dispersion of the refractive index. At 632.8 nm, the PbTiO(3) film with an (001) orientation exhibits a refractive index of 2.61, which represents 98% of the bulk material. The prism-coupling technique has been also employed to determine the optical attenuation in the planar waveguide. In this study, we report a low propagation loss of 2.2 ? 0.2 dB/cm obtained in a PbTiO(3) optical waveguide.     

基于柱状ZnO薄膜的超低阈值电压压敏电阻

利用磁控溅射法在玻璃衬底上制备了基于柱状ZnO薄膜的Al-ZnO-Al三明治结构的超低阈值电压的压敏电阻。XRD和SEM测试结果表明,该压敏电阻中的ZnO薄膜层为结晶性能良好,并且沿ZnO的(002)晶面择优取向生长的柱状薄膜。I-V测试结果表明,这种由柱状ZnO薄膜构成的压敏电阻阈值电压仅3.2 V,为现有压敏电阻中阈值电压最低的压敏电阻。     

铁电薄膜的制备及应用技术研究

研究出具有特色的制备铁电薄膜的 sol-gel技术;制备出高质量、高可靠的 PLT、PZT、PYZT、BST”l、PbTiO3、BaTiO3、Bi4Ti3O12多晶铁电薄膜,PLT、PZT和伽里O3异质外延生长铁电薄膜;研制出铁电薄膜热释电单元红外传感器,8元、9元、1O元线列和8X8元阵列;研制出热释电火情探测器和热释电非接触式温度测试仪。     

PZT纳米晶薄膜的Sol—Gel法制备及铁电性质

采用Ｓｏｌ－Ｇｅｌ法，以Ｚｒ的硝酸盐替代醇盐，引入ＰｂＴｉＯ３过渡层的方法成功的制备了纳米晶铁电薄膜。并进行了差热、热重、结构、组分、铁电性能的测定、分析。     

Morphology controlled fabrication and ferroelectric properties of vertically aligned one-dimensional lead titanate nanoarrays

Vertically aligned nanowires and highly uniform nanoporous array thin films of PbTiO(3) are synthesized by varying anodic oxidation conditions of Ti foil followed by hydrothermal reaction in an aqueous Pb(II) acetate trihydrate solution. As-synthesized samples have single crystalline nanowire structure and polycrystalline nanoporous structure, although both are pure PbTiO(3) with a tetragonal phase. The structure of intermediate TiO(2) films obtained from different anodic oxidation conditions determines the structure of the product PbTiO(3). The relationships between these morphological structures and ferroelectric properties are investigated. Piezoresponse force microscopy reveals that both these films show ferroelectricity with clear phase contrast and well-defined hysteresis loops. The saturated longitudinal piezoelectric coefficient field (E(c)) of the nanowire sample is smaller than that of nanoporous thin film. Thus, polarization of nanowire thin film is larger in magnitude and easier to flip than that of nanoporous film.     

溶胶凝胶合成PbTiO3／NiTi工艺研究

研究了溶胶凝胶工艺在NiTi基体表面复合PbTiO     

The effects of ZnO films on surface acoustic wave properties of modified lead titanate ceramic substrates

Poly-crystal zinc oxide (ZnO) films with c-axis (002) orientation have been successfully grown on the strontium (Sr) modified lead titanate ceramic substrates with different Sr dopants by r.f. magnetron sputtering technique. Highly oriented ZnO films with c-axis normal to the substrates can be obtained under a total pressure of 10 mTorr containing 50% argon and 50% oxygen and r.f. power of 70 W for 3 hours. Crystalline structures of the films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The phase velocity, electromechanical coupling coefficient and temperature coefficient of frequency of surface acoustic wave (SAW) devices with ZnO/IDT/PT (IDT, inter-digital transducer; PT, PbTiO3 ceramics) structure were investigated. The devices with ZnO/IDT/PT structure shows that the ZnO film effectively raise the electromechanical coupling coefficient (kappa2) from 3.8% to 9.9% of the device with the concentrations of Sr dopants of 0.15. It also improves the temperature coefficient of frequency of SAW devices.     

The role of atomic mobility during film growth in the structural and magnetic properties of CoCr

We have studied the morphological, crystallographic, and magnetic properties of CoCr thin films sputtered at different substrate temperatures and pressures. Conditions which produce high adatom mobility on the surface of the growing film lead to good c-axis orientation and magnetic anisotropy normal to the substrate, while low mobility leads to poor c-axis orientation and anisotropy. These results are explained in terms of van der Drift's model of the evolutionary growth of vapor-deposited films. The perpendicular coercivities of our samples depend only on the substrate temperature and we find no correlation with the film morphology or grain size.     

SAW器件用金刚石基c轴取向LiNbO3压电薄膜的制备

采用脉冲激光沉积技术,在以c轴取向ZnO作为缓冲层的金刚石/硅基底上制备出了结晶良好的高c轴取向LiNbO3薄膜。利用X射线衍射对薄膜的结晶质量和c轴取向性进行了研究,结果表明制得的LiNbO3薄膜具有高度c轴取向且结晶质量良好。采用扫描电子显微镜和原子力显微镜对薄膜的表面形貌进行了分析,发现薄膜表面光滑,晶粒尺寸均匀,薄膜表面粗糙度约为20nm。     

Synthesis of C-axis-oriented AlN thin films on high-conducting layers: Al, Mo, Ti, TiN, and Ni

Thin piezoelectric polycrystalline films such as AlN, ZnO, etc., are of great interest for the fabrication of thin film bulk/surface acoustic resonators (TFBARs or TFSARs). It is well-known that the degree of c-axis orientation of the thin films correlates directly with the electromechanical coupling. However, the degree of c-axis orientation of the piezoelectric film is, in turn, influenced by other parameters such as the structure of the substrate material, the matter of whether the c-axis is up or down (polarity), and the growth parameters used. The correlation of these three aspects with the electromechanical coupling of the AlN-thin films, is studied here. Thin AlN films, prepared in a magnetron sputtering system, have been deposited onto thin Al, Mo, Ni, Ti, and TiN films. Such thin high-conducting layers are used to form the bottom electrode of TFBAR devices as well as to define a short-circuiting plane in TFSAR devices. In both cases, they serve as a substrate for the growth of the piezoelectric film. It has been found that the degree of orientation and the surface roughness of the bottom metal layer significantly affects the texture of the AlN films, and hence its electroacoustic properties. For this reason, the surface morphology and texture of the metal layers and their influence on the growth of AlN on them has been systematically studied. Finally, FBARs with both Al and Ti electrodes have been fabricated and evaluated electroacoustically.