微波等离子体化学气相沉积制备SiCN结晶膜及SiCN微米棒阵列

本文采用微波等离子体化学气相沉积(MPCVD)系统,以CH4, H2, N2作为源气体,以Si棒作为Si源,在Si衬底上制备出了SiCN结晶及SiCN微米棒阵列.样品的形貌由场发射扫描电子显微镜(SEM)表征分析.用X射线光电子谱(XPS)、Raman散射谱及X射线衍射(XRD)对样品的键合状态及结构进行表征,结果表明,所得到的SiCN薄膜是一具有新的六方结构的三元化合物.     

Bi4Ti3O12铁电薄膜X射线光电子能谱研究

本文采用化学溶液沉积(CSD)工艺在Si(100)衬底上制备了Bi4Ti3O12铁电薄膜,这种薄膜的X射线衍射(XRD)结果显示其具有较好的结晶性.运用X射线光电能谱仪(XPS)对薄膜的结构进行了研究,分析结果表明,衬底中Si向镀在其上的Bi4Ti3O12膜层内扩散,影响扩散的主要因素是膜厚及退火温度.     

热丝辅助射频CVD C3N4薄膜

采用热丝辅助射频等离子体增强化学气相沉积(CVD)方法直接在Si(100)衬底上制备了多晶C3N4薄膜.X射线衍射(XRD)测试表明薄膜同时含有α-C3N4和β-C3N4晶相以及未知结构.傅立叶变换红外吸收谱(FTIR)表明薄膜内的C-N, C＝N和 C≡N 键的吸收峰分别位于1237,1625和2191cm-1.利用扫描电子显微镜(SEM)观测到线度约为2μm、横截面为六边形的β-C3N4晶粒.纳米压痕法测得薄膜的硬度最高可达72.66GPa.     

微波等离子体化学气相沉积制备碳氮晶体薄膜

利用微波等离子体化学气相沉积系统 ,以甲烷、氮气和氢气作为气源 ,在Si( 1 0 0 )衬底上成功地制备出了碳氮晶体薄膜 ,并对两种衬底温度下的薄膜性质进行了比较。用高分辨率场发射扫描电子显微镜观察薄膜 ,可以看出晶型完整 ,结构致密 ,结晶质量较好。X射线能谱证明了碳氮是以C─N和CN共价键的形式存在 ,氮碳元素的原子比均为 1 .3。X射线衍射确定出在衬底温度为 90 0± 1 0℃时薄膜样品的主要晶相成份是α C3N4,β C3N4,赝立方C3N4,立方C3N4和一个未知相 (面间距d =0 .4 0 0 2nm) ,而在 95 0± 1 0℃时薄膜样品的主要晶相成份是α C3N4,β C3N4,赝立方C3N4,类石墨C3N4和一个未知相 (面间距d =0 .3 984nm)。喇曼光谱分析也证实了薄膜中主要存在α C3N4,β C3N4相     

射频磁控溅射法制备TiO2-xNx薄膜的结构性能研究

利用射频磁控溅射法室温下在Si(100)衬底上制备了N掺杂的TiO2薄膜,并且采用x射线衍射(XRD)、X射线光电子能谱(XPS)和透射光谱对薄膜进行了表征.XRD结果表明在纯Ar和N2(33.3;)/Ar气氛下制备的TiO2-xNx薄膜均为单一的金红石相,薄膜结晶性良好,呈高度(211)择优取向,而在N2(50.0;)/Ar下制备的薄膜结晶性明显变差;对于N掺杂的TiO2薄膜,XPS表明部分N原子进入TiO2晶格,并且以N-Ti-O、N-O键以及间隙式N原子形式存在;透射光谱表明掺N后的TiO2薄膜吸收边发生了红移.     

大气开放式MOCVD氧化镁薄膜的生长及表征

以2,4-乙酰丙酮化镁为前驱体,衬底温度为480℃,采用MOCVD工艺,分别在玻璃、氧化铝陶瓷、单晶Si(111)和Si(100)衬底上生长了取向生长的氧化镁薄膜。X射线衍射结果表明,无论是采用玻璃、氧化铝、单晶Si(111)和Si(100)衬底,氧化镁薄膜都是沿着(100)晶面取向生长。通过扫描电镜观察得到,在单晶Si(100)衬底上生长的氧化镁薄膜表面平整致密。模拟卢瑟福背散射结果显示,沉积时间超过70min时,界面处发生硅向氧化镁层少量扩散现象。     

不同衬底表面上大晶粒多晶Si薄膜的制备

利用高频感应加热化学气相沉积(HFCVD)工艺,以H2稀释的SiH4作为反应气体源,分别在n-(111)Si衬底上常规热生长的SiO2层、织构的SiO2层和纳米晶粒多晶Si薄膜表面上,制备了具有均匀分布的大晶粒多晶Si膜.采用扫描电子显微镜(SEM)和X射线衍射(XRD)等检测手段,测量和分析了沉积膜层的表面形貌、晶粒尺寸、密度分布与择优取向等结构特征.结果表明,多晶Si膜中Si晶粒的尺寸大小和密度分布不仅与衬底温度、SiH4浓度与反应气压等工艺参数有关,而且强烈依赖于衬底的表面状态.本实验获得的最好的薄膜中,Si晶粒平均尺寸约为2.3 μm,密度分布约为3.8×107/cm2.对薄膜的沉积机理分析表明,衬底表面上Si原子基团的吸附、迁移、成核与融合等热力学过程支配着大晶粒多晶Si膜的生长.     

铁、氮共掺杂二氧化钛的水热法合成及其光催化性能研究

为了研制分解汽车尾气路面TiO2涂层,以钛酸丁酯为Ti源、硝酸铁为Fe源,尿素为N源,采用水热法合成了Fe-N共掺杂TiO2((Fe,N)-TiO2)纳米粉体.采用X射线衍射仪、透射电子显微镜、X射线光电子能谱、紫外-可见光谱仪等对样品进行了表征.结果表明合成的(Fe,N)-TiO2样品均为锐钛矿晶型,样品的平均粒径大小约为7.2nm.Fe、N共掺杂对TiO2的晶体结构没有明显影响,Fe和N离子都已经进入TiO2晶格.相对于纯TiO2而言,随着Fe和N离子的掺入,(Fe,N)-TiO2样品在可见光范围内吸光强度明显增强,光吸收带边发生红移.以可见光光催化降解亚甲基蓝(MB)研究了样品的光催化性能,(Fe,N)-TiO2对MB的降解能力较纯TiO2和N-TiO2有明显提高,说明Fe和N离子共掺杂会产生协同效应,使(Fe,N)-TiO2样品在可见光区域的光催化活性得到显著提高.     

α-Al2O3衬底上6H-SiC薄膜的SSMBE外延生长

采用固源分子束外延(SSMBE)技术,在α-Al2O3(0001)衬底上直接制备出了SiC薄膜.利用反射式高能电子衍射(RHEED)、Raman光谱、X射线扫描、傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)等实验技术,对生长的样品的结构和结晶质量进行了表征.结果表明:在蓝宝石衬底上生长出了结晶性能良好的6H-SiC薄膜,且薄膜中存在较小的压应力,这种压应力是由薄膜与衬底之间热膨胀系数的差异所致.     

Si基上电沉积Cu薄膜的形貌与择优取向

采用电化学沉积技术在Si衬底上沉积了Cu膜.场发射扫描电镜和X射线衍射分析表明:膜中存在Cu纳米颗粒, 并且表现出择优取向,与衬底的取向和斜切角度以及沉积电流密度有关.在Si(100) 衬底上,铜(220)晶面的织构系数随电流密度的增加而增加.在相同沉积条件下,在斜切角较小的Si(111)和Si(100)衬底上择优取向面都是铜 (220) 面,而在斜切角为4°的Si(111)衬底上铜(111)晶面为择优取向面.     

Photoluminescence in silicon/silicon oxide films produced by the Pulsed Electron Beam Ablation technique

In this work we report studies of the photoluminescence emission in samples based on Si/SiO_x films deposited by the Pulsed Electron Beam Ablation (PEBA) technique. The samples were prepared at room temperature using targets with different Si/SiO₂ concentrations. The samples were characterized using X-ray Absorption Edge Spectroscopy (XANES) at the Si―K edge, Raman spectroscopy, Photoluminescence (PL) and X-ray Photoelectron Spectroscopy (XPS). The concentration of a-Si and nc-Si in the film was dependent on the silicon concentration in the target. It was also observed that the PL is strongly dependent on the structural amorphous/crystalline arrangement.     

Aluminum induced formation of SiGe alloy in Ge/Si/Al thin film structure

In this work, a study of aluminum induced crystallization (AIC) of thin film germanium/silicon/aluminum (Ge/Si/Al) structure on oxidized silicon is presented. The Ge/Si/Al trilayer structure was prepared in three consecutive thin film deposition processes. The AIC was performed in nitrogen at 500 °C within time duration between 1 and 9 h. The progress of crystallization was monitored by optical microscopy, Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS). It was found that in Ge/Si/Al structure the AIC can lead to formation of SiGe alloy at temperature of 500 °C. This presents an alternative low-temperature formation method of SiGe which is suitable for integration with the conventional Si technology in electronic device fabrication.     

退火温度对Co掺杂CeO2稀磁氧化物薄膜的结构和铁磁性能的影响

采用溶胶-凝胶法,在Si(100)和石英玻璃衬底上制备了3;Co掺杂CeO2稀磁氧化物薄膜,研究了不同退火温度(500 ℃, 600 ℃和700 ℃)对薄膜结构和铁磁性能的影响.XRD 和拉曼光谱结果表明,随着退火温度的升高,薄膜晶化度明显提高.不同退火温度下的3;Co掺杂CeO2薄膜为多晶薄膜,且未破坏CeO2原有的结构.随着退火温度的升高, 晶粒尺寸逐渐增大.另外,3;Co掺杂CeO2薄膜在可见光范围内都有很好的透射率,其室温下的光学带隙Eg随退火温度增加而减小.超导量子干涉磁强计(SQUID)测量表明所有样品都表现出室温铁磁性,随着退火温度的升高,饱和磁化强度和矫顽力增大,700 ℃退火的薄膜具有最大的饱和磁化强度和最大的矫顽力.不同退火温度导致样品的磁性有了明显的变化,这源于磁性产生的不同机理.可见薄膜的结构最终影响了其铁磁性能.     

Optimizing the growth of CoSi2 film with oxide-mediated CoSi2 template by silicon cap layer

Applying both template and Si cap technology, we achieved the epitaxial growth of CoSi₂ directly on Si(1 0 0) substrate by rapid thermal annealing (RTA). The crystal quality of CoSi₂ film is found to be significantly dependent on the Si cap thickness. In our work, a good-quality CoSi₂ film with a minimum of χ_min~11.6% and 3.3 Ω/square was obtained as a 15 nm Co with a subsequent 15 nm Si cap layer is deposited on an oxide-mediated CoSi₂ template and followed by an anneal at 1050 °C under N₂ protection; whereas too thin or thick Si cap layer will deteriorate the crystalline quality of CoSi₂. These experimental results are discussed in combination with the simulation of Rutherford backscattering spectroscopy and X-ray reflectivity.     

Non-crystalline Zr–Si diffusion barrier for Cu/Si contact system under different sputtering power

Non-crystalline Zr–Si diffusion barrier in Cu/Si contact systems has been investigated. Zr–Si diffusion barriers were deposited on the silicon substrates by radio frequency reactive magnetron sputtering under different sputtering power. The Cu/Zr–Si/Si structures were manufactured and the diffusion barrier properties were investigated by heat-treating the structure in Ar ambient at temperatures ranging from 500 to 650 °C for an hour. X-ray diffraction (XRD), Auger electron spectroscopy (AES), and scanning electron microscopy (SEM) technique were applied to characterize the diffusion barrier performance for Zr–Si in Cu/Zr–Si/Si structures. It is indicated from the comparison analysis results that the Zr–Si film showed a better diffusion barrier performance with the larger sputtering power.     

硅铝共掺杂对TiO2薄膜结构及性能的影响

采用非水解溶胶-凝胶法制备了Si、Al共掺杂的TiO2薄膜.应用X射线衍射、紫外可见分光光度计研究了Si、Al掺杂对TiO2薄膜晶型转变、晶粒尺寸、光吸收性能及光催化性能的影响.结果表明:适量引入Si、Al后,可显著提高1000℃热处理后TiO2薄膜的光催化活性;当Si/Ti物质的量比为0.2时,薄膜由于混晶结构光催化活性最佳;Si、Al共掺杂能抑制TiO2的晶型转变及TiO2的晶粒生长,且Si、Al共掺杂的抑制作用比单一Si掺杂更有效;当Si/Ti物质的量比为0.15、Al/Ti物质的量比为0.05时,TiO2锐钛矿向金红石的转变温度从750℃提高到1200℃.     

真空退火处理对纳米氮化硅电子自旋共振谱的影响

用微米级SiO2、Si和碳黑混合粉末为原料, 以氮气为反应气,采用碳热还原法合成了氮化硅纳米粉体.测量了300～1273K退火温度下纳米氮化硅的电子自旋共振(ESR)谱,研究了测量温度、纳米氮化硅退火温度对ESR谱线型、g因子、线宽的影响.结果证实退火影响纳米氮化硅的磁性.     

Structure and optical properties of light-emitting Si films fabricated by neutral cluster deposition and subsequent high-temperature annealing

As a new development of our previous study on the production of light-emitting amorphous Si (a-Si) films by the neutral cluster deposition (NCD) method, we have fabricated light-emitting Si films with improved emission intensity by the combined methods of NCD and subsequent high-temperature annealing. The structure of these films is best characterized by Si nanocrystals, surrounded by an interfacial a-SiO_x (x < 2) layer, embedded in an a-SiO₂ film. These improved Si films were observed by atomic force microscopy and high-resolution transmission electron microscopy, and analyzed by means of X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescence (PL) and Fourier transform infrared-attenuated total reflection measurements. The PL curves of the annealed samples exhibit peaks around 600 nm, at almost the same position as the unannealed samples. Their PL intensities, however, have increased to approximately five times those of the unannealed samples. The source of the luminescence is most likely due to electron-hole recombination in the a-SiO₂/Si interfacial a-SiO_x layer.     

类石墨氮化碳薄膜的电化学沉积

用1:1.5的三聚氯氰和三聚氰胺的饱和乙腈溶液为沉积液,在Si(100)衬底上室温常压下电化学沉积了CNx薄膜.用X射线光电子能谱(XPS)、傅立叶转换红外光谱(FTIR)、X射线衍射图谱(XRD)对沉积的CNx薄膜进行了测试和分析.XRD的衍射峰的结构数据与文献计算的类石墨相氮化碳的结构数据较为吻合.XPS结果表明沉积的薄膜中主要元素为C、N,且N/C=0.81,C1s和N1s的结合能谱中287.84eV的碳和400.00eV的氮是样品中碳氮的主体,以C3N3杂环的形式存在.FTIR光谱中在800cm-1、1310cm-1和1610cm-1的吸收峰也表明薄膜中存在C3N3环,和XPS能谱的分析结果一致.Teter和Hemley预言的g-C3N4在结构形式上和三聚氰胺的完美脱胺缩聚物是一样的,红外光谱和X射线光电子能谱表明在样品中存在三嗪环(C3N3),支持XRD的实验结果.这说明CNx薄膜中有类石墨相的C3N4晶体存在.