不同衬底上Pb(Zr0.52Ti0.48)O3择优取向铁电薄膜的制备和研究

通过MOD法在Si(100)和Pt(111)/Ti/SiO2/Si基片上制备出LaNiO3 (LNO)薄膜.再通过修正的Sol-gel法,在Pt(111)/Ti/SiO2/Si,LNO/Si(100)和LNO/Pt/Ti/SiO2/Si三种衬底上制备出具有择优取向的Pb(Zr0.52Ti0.48)O3铁电薄膜.经XRD分析表明,LNO薄膜具有(100)择优取向的类钙钛矿结构;PZT薄膜均具有钙钛矿结构,且在Pt(111)/Ti/SiO2/Si衬底上的薄膜以(110)择优取向,在LNO/Pt/Ti/SiO2/Si和LNO/Si(100)衬底上的薄膜以(100)择优取向.经场发射SEM分析和介电、铁电性能测试表明,在LNO/Si和LNO/Pt/Ti/SiO2/Si衬底上的PZT薄膜的平均粒径、介电常数以及剩余极化强度均比以Pt/Ti/SiO2/Si为衬底的薄膜大.     

不同衬底上Pb(Zr0.52Ti0.48)O3择优取向铁电薄膜的制备和研究

通过MOD法在Si(100)和Pt(111)/Ti/SiO₂/Si基片上制备出LaNiO₃ ( LNO)薄膜.再通过修 正的Sol-gel法，在Pt(111)/Ti/SiO₂/Si,LNO/Si(100)和LNO/Pt/Ti/SiO_{2< /sub>/Si三种衬底上 制备出具有择优取向的Pb(Zr0.52Ti0.48)O3铁电薄膜. 经XRD分析表明，L NO薄膜具有(100)择优取向的类钙钛矿结构；PZT薄膜均具有钙钛矿结构，且在Pt(111)/Ti/S iO2/Si衬底上的薄膜以(110)择优取向，在LNO/Pt/Ti/SiO2/Si和LN O/Si(100)衬底上的 薄膜以(100)择优取向.经场发射SEM分析和介电、铁电性能测试表明，在LNO/Si和LNO/Pt/Ti /SiO2/Si衬底上的PZT薄膜的平均粒径、介电常数以及剩余极化强度均比以Pt/T i/SiO2/Si为衬底的薄膜大. 关键词： 3}薄膜')" href="#">LaNiO₃薄膜 PZT铁电薄膜 择优取向 剩余极化强度     

Si衬底上磁控溅射法生长MgO薄膜

我们用射频磁控溅射方法,在Si(100)单晶衬底上生长MgO薄膜,借助X射线衍射(XRD)分析发现,我们获得了两种不同晶体结构的MgO薄膜,分别是常规的晶格常数为0.421nm的MgO薄膜和晶格常数为0.812nm的新结构的MgO薄膜.我们研究了溅射气压、衬底温度等工艺参数对两种晶体结构择取的影响.实验表明,高的溅射气压和高的衬底温度有利于晶格常数为0.812nm的新结构的MgO相的形成.在高的气压和温度下,我们制备出了晶格常数为0.812nm,具有很好的4次对称性的MgO外延薄膜.利用原子力显微镜(AFM)研究了这种薄膜的表面形貌.     

高择优取向铌酸锶钡薄膜的射频磁控溅射制备

采用溶胶-凝胶法在(100)Si单晶上预先制备出掺钾(K)的铌酸锶钡(SBN)缓冲层,利用射频磁控溅射法在缓冲层KSBN上沉积出高择优取向的铌酸锶钡薄膜,获得了磁控溅射法制备择优取向铌酸锶钡薄膜的相关工艺参数,研究发现,KSBN缓冲层能够很有效地克服衬底与SBN薄膜之间较大的晶格失配,在氧气氩气的比例为1∶2,工作气压为10 Pa,溅射功率300 W,衬底温度300℃,退火温度为800℃的工艺条件下,能够获得c轴高度择优取向的铌酸锶钡铁电薄膜.利用X射线衍射仪,原子力显微镜等仪器分析了薄膜 关键词： 磁控溅射 高择优取向 p-n结效应     

择优取向MgO缓冲层上制备的硅基Ba0.7Sr0.3TiO3薄膜的结构和性能研究

分别采用sol-gel法和磁控溅射法在Si（001）单晶衬底上制备出（111）和（001）取向的MgO缓冲层薄膜,随后在其上生长Ba_0.7Sr_0.3TiO₃（BST30）铁电薄膜.通过X射线衍射,扫描电子显微镜,原子力显微镜等方法研究了薄膜的微结构.实验结果发现,在较厚的MgO（001）缓冲层上可长出（101）取向的BST30薄膜,而在较薄的MgO（111） 缓冲层上则表现出（101）和（111）取向相互竞争的现象,随着MgO（111）缓冲 关键词： 0.7Sr_0.3TiO₃')" href="#">Ba_0.7Sr_0.3TiO₃ 铁电薄膜 择优取向 sol-gel     

TiN薄膜在纳米压痕和纳米划痕下的断裂行为

利用磁控溅射方法在Si(111)衬底上制备了具有(111)和(222)择优取向的TiN薄膜. 用纳米压痕和纳米划痕方法研究了该薄膜的变形和断裂行为. 用扫描电子显微镜、纳米压痕原位原子力显微镜及原位光学显微镜并结合加-卸载 曲线及划痕曲线获得了薄膜发生变形和断裂的微观信息. 在压痕试验中, TiN薄膜在压入深度为200 nm时表现为塑性变形及压痕周围的局部断裂, 随着压入深度的增大, 塑性变形和局部断裂变得越显著, 当最大压入深度达到临界值1000 nm时, 薄膜和衬底间发生了界面断裂. 在划痕实验中, 100 mN及200 mN的最大载荷均可以引起界面断裂. 最大为200 mN的载荷使得薄膜发生界面断裂的位置比用100 mN载荷时的位置提前, 但其临界断裂载荷和100 mN时及压痕实验时的临界界面断裂载荷基本相同. 关键词： TiN薄膜 纳米压痕 纳米划痕 界面断裂     

高择优取向硅基含钾铌酸锶钡（K:SBN）薄膜的制备与性能

采用NbCl5作为先驱物，利用溶胶-凝胶法在Si(100)衬底上成功获得高度择优取向的铁电铌酸锶钡(SBN)薄膜.与用Nb(OC2H5)5作为先驱物的SBN薄膜相比，NbCl5配制的薄膜前驱溶液中含有一定数量的K离子.K离子的含量对SBN薄膜取向的影响存在一个最优值.二次离子质谱测试发现，K离子对SBN晶胞的溶入和对Si衬底的渗透能够同时使SBN晶胞和Si晶胞产生微小扭曲，从而起到调整薄膜与衬底的匹配关系，并最终促使SBN薄膜c轴高度择优取向的生长.测试了薄膜的光学特性. 关键词： 铌酸锶钡 溶胶-凝胶方法 择优取向     

薄膜光学 薄膜光学理论与膜系设计

O484.12006054374用PLD法在MgO(100)衬底上生长ZnO薄膜的结构和光学特性=Structural and optical properties of ZnOfil ms de-posited on MgO(100)substrates by PLD[刊,中]/苏凤莲(安徽大学物理与材料科学学院.安徽,合肥(230039)),汪洪…//安徽大学学报(自然科学版).—2006,30(2).—67-70用脉冲激光沉积法在MgO(100)衬底上沉积了ZnO薄膜,衬底温度分别为400℃、550℃和700℃。利用X射线衍射(XRD)和光致发光谱(PL)对薄膜的结构和光学性能进行研究。X射线衍射的结果表明,在400℃和550℃下生长的ZnO薄膜具有高度c-轴择优取向,但是…     

高择优取向铌酸锶钡薄膜的射频磁控溅射制备

采用溶胶-凝胶法在(100)Si单晶上预先制备出掺钾(K)的铌酸锶钡(SBN)缓冲层，利用射频磁控溅射法在缓冲层KSBN上沉积出高择优取向的铌酸锶钡薄膜，获得了磁控溅射法制备择优取向铌酸锶钡薄膜的相关工艺参数，研究发现，KSBN缓冲层能够很有效地克服衬底与SBN薄膜之间较大的晶格失配，在氧气氩气的比例为1∶2，工作气压为10 Pa，溅射功率300 W，衬底温度300℃，退火温度为800℃的工艺条件下，能够获得c轴高度择优取向的铌酸锶钡铁电薄膜.利用X射线衍射仪，原子力显微镜等仪器分析了薄膜     

室温和液氮温度Si基底C60薄膜的微观结构与光学特性比较研究

在室温和液氮温度（77K）下用蒸镀法在Si(111)衬底上制备C60薄膜，用扫描电子显微镜（SEM）研究两种不同基底上制备薄膜的微观结构，并用椭圆偏振光谱仪测量了光学参数（包括吸收光谱，折射率及光频介电常数），结果表明，衬底温度降低，薄膜更均匀，颗粒更细，光学吸收峰位置出现蓝移且在整个光频范围吸收增强。     

Epitaxial lithium fluoride films grown by pulsed laser deposition

Lithium fluoride (LiF) films have been prepared on LaAlO₃ (LAO), MgO, Si and TiN buffered Si substrates using a pulsed laser deposition (PLD) technique. Their surface morphology and structural qualities were studied by using scanning electron microscopy (SEM) and X-ray diffractometry (XRD). Those films deposited on (100)MgO and (100)TiN buffered Si exhibited (200)_LiF||(200)_MgOand(200)_LiF||(200)_TiN||(200)_Si epitaxial relationships, respectively. These results suggest that LiF films can be epitaxially grown on lattice match substrates and, for the first time, on (100)Si via a buffer layer. LiF grown on bare (100)Si and (100)LAO substrates, however, yielded films of (100) preferred orientation only. Lattice mismatch and thermal effects are invoked to explain these observations. The surfaces of the LiF films are very rough and covered with large globules due to splashing of molten droplets from the target. In order to remedy such deficiencies we used a shadow mask to reduce both the size and the number of these globules while maintaining the heteroepitaxial properties. As a result optically smooth LiF films of excellent structural quality are produced. PACS 78.55.FV; 81.15.FG; 68.55.JK     

TiN growth on Si by hybrid radical beam PLD

High-quality (good crystallinity and stoichiometry) titanium nitride (TiN) thin films were grown on Si(100) substrates by pulsed laser deposition (PLD) using a high-purity titanium target (99.99%) and nitrogen radical beam. The crystallinity, chemical composition, and depth profiles of the grown films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering spectroscopy (RBS), respectively. The XRD pattern indicated that the preferred growth of TiN(200) with an orientation parallel to the Si(100) direction was obtained and the nitrogen radical drastically improved crystallinity compared with that grown in ambient nitrogen gas. RBS spectra indicated that the combination of PLD and the nitrogen radical beam suppressed silicidation at the interface between the Si substrate and TiN thin film during growth. The XPS analysis revealed that this method achieved the synthesis of stoichiometric TiN films.     

Layer-by-layer growth of MgO thin films controlled by inserting a TiN seed layer using an in-situ pulsed laser deposition

Completely (200)-oriented MgO films were grown on Si(100) with insertion of a TiN seed layer by pulsed laser deposition (PLD). Compared with the conventional direct ablation of a metal Mg or ceramic MgO target, we successfully demonstrated an effective way to improve the crystallinity of MgO thin films. By using TiN as a seed layer, high-quality MgO films with an atomic-scale smooth surface of about 0.55 nm (Ra) were obtained. Moreover, it is found that the quality of MgO films was independent of the thickness of the TiN seed layer. The improved crystalline quality of the MgO films was attributed to the layer-by-layer growth mode during the deposition of MgO films, which was monitored in-situ by reflection high energy electron diffraction (RHEED). PACS 68.55.Jk; 81.15.Fg     

以MgO为缓冲层的硅基铌酸锶钡薄膜取向特性与其波导结构的设计研究

采用溶胶－凝胶法在Si(100)基片上制备出择优取向的MgO薄膜,随后在其上生长出具有择优取向的铌酸锶钡铁电薄膜.实验发现,MgO缓冲层的应用可以大大提高SBN薄膜的择优取向性能.同时,用五层对称理想波导耦合模理论,以SBN为波导层,分析了波导损耗与厚度的关系. 通过对计算出的理想结果与实际相结合,以及对SBN在生长过程工艺与损耗关系的研究,制备出高质量、低损耗的SBN薄膜,为其在电光波导调制器等微系统中的应用打下良好的基础.     

Fabrication of MgO barrier for a magnetic tunnel junction in as-deposited state using amorphous RE–TM alloy

MgO (1 0 0) textured films on Fe buffer layer with (1 0 0) preferential orientation were prepared by a reactive facing targets sputtering system at a substrate temperature of 100 °C during MgO deposition. This process can allow fabrication of MgO (1 0 0) tunneling barrier layer without high-temperature annealing process after the sputter-deposition. In addition, FeCo (1 0 0) preferred orientation films prepared on GdFeCo layers were improved with GdFeCo thickness. MgO films deposited on Fe (or FeCo) buffer layers revealed apparent (1 0 0) preferred orientation at the early stage of the film growth. 3 nm-thick MgO films deposited on GdFeCo [100 nm]/Fe [3 nm] exhibited (1 0 0) texture. Magnetic characteristic of perpendicular-magnetic tunnel junction (P-MTJ) element with the structure of GdFeCo [100 nm]/Fe [3 nm]/MgO [3 nm]/Fe [3 nm]/TbFeCo [100 nm] exhibited high squareness ratio of 0.8 and coercivity of free layer as low as 117 Oe by anomalous Hall effect, and (1 0 0) preferred orientation of 3 nm-thick MgO layer was observed by an X-ray diffractometer.     

基片对交替溅射制备的MnZn铁氧体薄膜结构和磁性的影响

使用成分分别为MnFe₂O₄和ZnFe₂O₄的靶,使用射频溅射交替沉积制备了成分不同的Mn_1-xZn_xFe₂O₄薄膜,沉积薄膜所用基片分别为单晶硅Si（100）,氧化的单晶硅SiO₂/Si（100）, ZnFe₂O₄为衬底的单晶硅ZnFe< 关键词： MnZn铁氧体 纳米晶 软磁性 磁性薄膜     

Enhanced strain relaxation induced by epitaxial layer growth mode of MgO thin films

Growth of MgO films on silicon substrate was conducted by KrF excimer pulsed-laser ablation system. Two kinds of growth mode were revealed in situ by reflection high energy electron diffraction. It was found that the layer growth mode of MgO thin films could remarkably reduce the misfit strain originated from the different lattice constant and thermal expansion coefficiency between MgO films and Si. An enhanced strain relaxation was discovered for MgO films, which were grown with the layer growth mode, in the film thickness range of 40-100 nm. The value of critical thickness for the formation of misfit dislocation agrees well with the calculated one. This exceptional phenomenon should be ascribed to the layer growth mode of epitaxial MgO films.     

Synthesis and characterization of superhard Ti-Si-N films obtained in an inductively coupled plasma enhanced chemical vapor deposition (ICP-CVD) with magnetic confinement

Using a novel inductively coupled plasma enhanced chemical vapor deposition (ICP-CVD) with magnetic confinement system, Ti-Si-N films were prepared on single-crystal silicon wafer substrates by sputtering Ti and Si (5 at.%:1 at.%) alloyed target in argon/nitrogen plasma. High-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), X-ray diffractometer (XRD), field emission scanning electron microscope (FESEM), atomic force microscopy (AFM) and Nano Indenter XP tester were employed to characterize nanostructure and performances of the films. These films were essentially composed of TiN nanocrystallites embedded in an amorphous Si₃N₄ matrix with maximum hardness value of 44 GPa. Experimental results showed that the film hardness was mainly dependent on the TiN crystallite size and preferred orientation, which could be tailored by the adjustment of the N₂/Ar ratio. When the N₂/Ar ratio was 3, the film possessed the minimum TiN size of 10.5 nm and the maximum hardness of 44 GPa.