透射电子显微镜对接膜样品的制作

在透射电子显微镜(TEM)样品制作中,对接膜样品制作最为复杂,同时得到的薄膜信息也非常多,是进行材料研究的一个非常有用的观测方法.并介绍了这种样品的制作过程和样品的测试分析情况.     

空间分辨电子能量损失谱对合金高温氧化的研究

空间分辨电子能量损失谱（Spatially-resolved EELS）是指在利用配备有能量过滤系统的透射电子显微镜（Energy filter coupled TEM）采集电子能量损失谱时，通过调整样品取向使得样品表面与EELS能量色散方向平行，从而在采集电子能量损失谱时在垂直于能量色散方向具有一定的空间分辩率的实验方法。对于同一元素，当处于不同化学环境时，其电子能量损失近阈精细结构（Energy Loss Near Edge Structure,ELNES）升起点处的绝对能量会有所差异，     

电子显微镜的现状与展望

本文扼要介绍了电子显微镜的现状与展望，透射电子显微镜方面主要有：高分辨电子显微学及原子像的观察，像差校正电子显微镜，原子尺度电子全息学，表面的高分辨电子显微正面成像，超高压电子显微镜，中等电压电镜，１２０ｋＶ，１００ｋＶ分析电镜，场发射枪扫描透射电镜及能量选择电镜等，透射电镜将又一次面临新的重大突破，扫描电子显微镜方面主要有：分析扫描电镜和Ｘ射线能谱仪，Ｘ射线波谱仪和电子探针仪，场发射枪扫描电镜和     

透射电子显微镜单色器的发展及应用

自1932年透射电子显微镜发明以来,透射电子显微学在基础理论、仪器研制及其在材料科学、生命科学等领域的应用得到了迅速发展,200kV场发射枪透射电子显微镜的点分辨率已达0.19～0.25nm,能量分辨率为0.7～1.0eV。进一步提高透射电子显微镜性能的关键在于降低物镜球差和电子束能量扩散等。球差校正器的发明使透射电镜的点分辨率已突破0.1nm,电子源色差已成为进一步提高电子显微镜信息分辨极限和电子能量损失谱能量分辨率的瓶颈。在场发射枪透射电子显微镜上增加单色器（能量过滤器）可有效降低电子束的能量色散,减小色差对电子显微镜性能的影响。本文介绍了Wien型、Ω型及Mandoline型等几种常见的能量过滤器的工作原理、结构、性能及其应用。     

多量子阱结构不均匀性的TEM观察

用横断面透射电子显微镜(XTEM)技术对分子束外延GaAs-Al_xGa_(1-x)As多量子阱结构进行了观察,实验结果表明光荧光发射谱的宽化可能和阱宽的不均匀性有关.     

聚焦离子束制备透射电子显微镜样品的两种厚度判断方法

透射电镜样品的厚度是透射电镜(TEM)表征中一个重要参数,快速准确地判断样品厚度是制备高质量样品的前提.本文通过使用聚焦离子束(FIB)制备了带有厚度梯度的透射电镜样品(Si、SrTiO3和LaAlO3),并提出两种制样过程中快速判断厚度的方法.第一种通过扫描电子显微镜(SEM)的衬度变化经验地判断样品的厚度;第二种是用FIB在样品边缘切一个斜边,通过SEM测量斜边侧面的宽度用几何方法推断样品的厚度.这两种方法都通过会聚束电子衍射(CBED)和电子能量损失谱(EELS)测量的厚度作为检验标准.对比认为,样品较薄时用SEM衬度测厚比较合适;样品比较厚时用几何方法测量比较直接.     

碲锌镉晶片中位错与Te沉淀的透射电子显微分析

采用透射电子显微镜对碲锌镉晶体材料的缺陷特性进行了分析，观察并研究了碲锌镉晶体中Te沉淀相形貌和Te沉淀周围的棱柱位错环. 认为棱柱位错的形成是由Te沉淀相的析出引起的，而沉淀相在基体中的析出与基体形成错配应力，又造成位错的增殖. Te沉淀与棱柱位错两种缺陷是相互依存的.     

碲锌镉晶片中位错与Te沉淀的透射电子显微分析

采用透射电子显微镜对碲锌镉晶体材料的缺陷特性进行了分析,观察并研究了碲锌镉晶体中Te沉淀相形貌和Te沉淀周围的棱柱位错环.认为棱柱位错的形成是由Te沉淀相的析出引起的,而沉淀相在基体中的析出与基体形成错配应力,又造成位错的增殖.Te沉淀与棱柱位错两种缺陷是相互依存的.     

透射电子显微镜高压电源箱气体绝缘技术及充气工艺

本文通过比较高压系统常用气态绝缘介质的性能,对比影响气体绝缘性能的关键参数,给出了透射电子显微镜高压电源箱绝缘材料的优化选择,介绍了六氟化硫(SF6)气体在透射电子显微镜高压电源绝缘中的应用,计算了充SF6绝缘气体的高压电源箱,并给出了透射电子显微镜高压箱的绝缘充SF6气体工艺.     

Ge2Sb2Te5相变存储单元有源区对RESET电流影响的研究

应用透射电子显微镜技术和数值模拟计算,对基于材料Ge_2Sb_2Te_5的相变存储器单元有源区RESET电流的影响进行了研究,主要包括有源区晶粒结构和晶粒区域大小对RESET电流的影响。综合分析透射电子显微镜、数值模拟和实际测试结果,最终发现通过得到较大的材料晶粒为立方晶相的有源区域,可以有效地降低后续操作的RESET电流。     

离子束增强沉积氮化硅薄膜生长及其性能研究

用离子束增强沉积技术合成了氮化硅薄膜并研究了薄膜的组分、性能和结构.结果表明,离子束增强沉积生长的氮化硅薄膜的组分比,可借助于调节氮离子和硅原子到达率之比加以控制.在合适条件下生长的氮化硅薄膜,其红外吸收特征峰在波数为840cm~(-1)附近,光折射率在2.2到2.6之间,其组分为Si_3N_4用RBS、AES、TEM、SEM、ED及扩展电阻,测量和观察生成的氮化硅薄膜的组分深度分布及结构.发现,离子束增强沉积制备的氮化硅薄膜,存在着表面富硅层、氮化硅沉积层及混合过渡层这样的多层结构.薄膜呈球状或方块状堆积.基本上是无定形相,但局部可观察到单晶相的存在.离子束增强沉积制备的氮化硅薄膜中的含氧量比不用离子束辅助沉积的显著减少.     

Room temperature deposition of silicon nitride films using very low frequency (50Hz) plasma CVD

Silicon nitride films have been deposited by low frequency 50Hz plasma CVD using a nitrogen and silane mixture at room temperature. To deposit high quality silicon nitride, the silane fraction in the nitrogen and silane mixture has to be less than 5 %. The refractive index, breakdown field strength and resistivity of the obtained silicon nitride film were 2.0, 1.2x10⁷ V/cm and 6x10¹⁵ Ωcm, respectively. Mechanism of the deposition of high quality silicon nitride is discussed on the basis of the experimentally observed light emission spectrum from the plasma and of the electron energy distribution function in the plasma theoretically calculated by the Boltzmann equation method.     

Ultra-dense hydrogen silsesquioxane (HSQ) structures on thin silicon nitride membranes

Ultra-dense nanometer-scale gratings (20 nm pitch) on thin silicon nitride (Si₃N₄) membrane substrates using hydrogen silsesquioxane (HSQ) resist have been fabricated. Scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) were performed to evaluate the pattern quality of the HSQ gratings. The results are compared with HSQ gratings fabricated on silicon substrates.     

A polycide gate electrode with a conductive diffusion barrierformed with ECR nitrogen plasma for dual gate CMOS

A simple diffusion barrier technology for polycide gate electrodes is presented. An extremely thin silicon nitride layer is formed by poly Si surface nitridation with ECR nitrogen plasma of only nitrogen gas and without substrate heating. The silicon nitride layer acts as an excellent barrier to impurity diffusion from polysilicon to silicide. It was found that barrier formation with ECR nitrogen plasma results in no fatal degradation in the MOS interface characteristics. This technology is very effective for making dual polycide gates inexpensively due to its simplicity and a good affinity with conventional ULSI fabrication processes     

Remote plasma-enhanced CVD of silicon nitride films: effects of diluting nitrogen with argon. Part I: effect on nitrogen plasma parameters studied by emission spectroscopy

In a series of two papers we describe the effect of argon dilution of the nitrogen passed through the RF discharge region on the plasma composition, growth rate and some characteristics of silicon nitride films deposited by remove PECVD. In this part we report the results of an emission spectroscopic study of the plasma obtained in an SiH₄–N₂–Ar mixture. It is shown that argon in metastable electronic excited states plays an important role during the RPECVD of silicon nitride films by providing a high concentration of atomic nitrogen which is necessary for the promotion of film growth. In Part II the influence of argon dilution on the growth rate, composition and some properties of silicon nitride films deposited by capacitively and inductively coupled remote PECVD is discussed. © 1998 John Wiley & Sons, Ltd.     

Tunneling leakage current in oxynitride: dependence onoxygen/nitrogen content

It is widely known that the addition of nitrogen in silicon oxide, or the addition of oxygen in silicon nitride, affects its reliability as a gate dielectric. The authors examine the gate leakage current as a function of the oxygen and nitrogen contents in ultrathin silicon oxynitride films on Si substrates. It is shown that, provided that electron tunneling is the dominant current conduction mechanism, the gate leakage current in the direct tunneling regime increases monotonically with the oxygen content for a given equivalent oxide thickness (EOT), such that pure silicon nitride passes the least amount of current while pure silicon oxide is the leakiest     

SIMS study of silicon oxynitride prepared by oxidation of silicon-rich silicon nitride layer

We proposed a novel process for fabrication silicon oxide–oxynitride–oxide structure for ULSI device applications. By deposition of silicon-rich silicon nitride and then following a thermal oxidation process, a good oxynitride layer was obtained. Secondary ion mass spectroscopy (SIMS) study reveals that the hydrogen content of nitride film at the interface can be reduced by more than 40% when compared to stoichiometric nitride. With this method, high nitrogen content oxynitride and smoother oxynitride/oxide interfaces result in the reduction of the interface charge trapping remarkably.     

Silicon surface treatment by pulsed nitrogen plasma

The structure of silicon single crystals after plasma treatment was studied by infrared spectroscopy and electron microscopy. It is shown that on irradiation by pulsed nitrogen plasma a silicon nitride is formed in the surface region.     

Gas composition dependence of silicon nitride used as gallium diffusion barrier during GaAs molecular beam epitaxy growth on Si complementary metal oxide semiconductor

We have measured the effect of deposition parameters upon the utility of plasma enhanced chemical vapor depositon silicon nitride as a gallium diffusions barrier during molecular beam epitaxy growth of gallium arsenide on silicon submicron complementary metal oxide semiconductor electronics. It was found that the conditions under which the silicon nitride is deposited severely impact the ability of these films to be used as a diffusion barrier, with the most critical dependence upon the silane to nitrogen gas ratio.     

Low-temperature deposition of silicon oxide and silicon nitride by reactive magnetron sputtering

In this study, oxide and nitride films were deposited at room temperature through the reaction of silicon sputtered by argon and oxygen ions or argon and nitrogen ions at 250 and 350 W with 0.67 Pa pressure. It was observed that for both thin films the deposition rates increase with the applied RF power and decrease with the increase of the gas concentration. The Si/O and Si/N ratio were obtained through RBS analyses and for silicon oxide the values changed from 0.42 to 0.57 and for silicon nitride the values changed from 0.4 to 1.03. The dielectric constants were calculated through capacitance-voltage curves with the silicon oxide values varying from 2.4 to 5.5, and silicon nitride values varying from 6.2 to 6.7, which are good options for microelectronic dielectrics.