金属／石墨界面扩散反应的AES研究

利用扫描俄歇微探针的深度分析和线形分析，研究了石墨与金属Ｔｉ，Ｃｒ之间的界面状态和相互作用。研究结果表明，样品真空热处理后，在Ｔｉ／石墨、Ｃｒ／石墨薄膜界面上发生了界面扩散和化学反应，生成了ＴｉＣ和Ｃｒ３Ｃ２等金属碳化物物种，促使Ｔｉ，Ｃｒ薄膜与界石墨形成了良好的化学结合状态。     

金刚石薄膜的表面金属化及与Ti薄膜的界面扩散反应的AES研究

利用磁控溅射的方法在金刚石薄膜表面沉积了２５０ｎｍ厚的金属Ｔｉ层，通过３００￣６００℃的真空热处理，促进了Ｔｉ与金刚石之间的界面扩散反应。利用俄歇电子能谱研究了Ｔｉ／金刚石薄膜界面的结合状态，发现在界面上形成了Ｔｉ的碳化物。并发现Ｔｉ与金刚石薄膜发生了大幅度的界面扩散反应，Ｔｉ元素渗入金刚石层达６００ｎｍ，促进了Ｔｉ与金刚石之间形成良好的化学结合，为获得高性能的金刚石切削工具提供了可能。界面扩散反     

氢离子束对Mo—Si多层膜界面改性的研究

为了研究氢离子束轰击Ｍｏ－Ｓｉ多层膜界面的情况，采用氢离子束（能量１５０ｅＶ）轰击Ｓｉ表面，即Ｓｉ与Ｍｏ之界面，再用Ｋｒ离子束溅射刻蚀，并用俄歇电子能谱（ＡＥＳ）分析，实验结果说明氢离子束对Ｓｉ表面轰击能有效防止界面混杂效应，进而说明这是制备软Ｘ射线多层膜反射镜过程中解决界面混杂问题的有效途径。     

铜上溅射沉积铀薄膜AES研究

在俄歇电子能谱仪超高真空室内,采用离子束溅射沉积方法在多晶cu上沉积了铀薄膜,采用俄歇电子能谱技术(AES)研究铀薄膜的生长方式,铀、铜的相互作用及退火引起u膜成分结构变化.沉积初期观察到铀与铜发生相互作用,随着铀薄膜厚度的增加,UOPV/CuLMM俄歇跃迁峰强度值变化说明铀薄膜为层状+岛状生长.退火促进了界面扩散,随着温度的升高,铀与铜发生了相互作用和扩散,温度继续升高,铀与碳形成了铀碳化物.     

SiO_2层对金刚石膜初期生长影响的研究

用俄歇子能谱（AES）研究了热丝法生长金刚石膜中未经划痕处理的单晶硅衬底在不同沉积时间下的表面结构及Si，C，O元素浓度的深度分布。结果表明：在沉积过程中，随沉积时间增加时，基材表面C浓度增加，O浓度下降，但SiC过渡层的生长缓慢。700℃沉积4h时仍无结构完整的SiC层生成，这是表面SiO2层阻碍了SiC的形成。分析了不经划痕处理的基材形核率低的原因。用高分辨电镜（HREM）观察了生长良好的金刚石膜的膜—基界面，发现没有SiO2层存在。     

Ni3Al金属间化合物及溅射CoCrAlY涂层的高温热腐蚀

研究了Ｎｉ３Ａｌ金属间化合物及溅射ＣｏＣｒＡｌＹ涂层在９００～９５０℃空气中，表面存在（Ｎａ，Ｋ）２ＳＯ４盐膜时的热腐蚀行为，结果表明，Ｎｉ３Ａｌ遭受严重的热腐蚀，溅射ＣｏＣｒＡｌＹ涂层可以通过在表面迅速形成保护性Ａｌ，Ｃｒ氧化膜而显著改善Ｎｉ３Ａｌ的耐热腐蚀性能。     

中性银粒子和银离子在Si(111)上沉积过程的AES研究

无论是蒸发沉积、离子溅射沉积、离子束沉积还是其它类型的沉积,所沉积的薄膜的微观结构、薄膜与衬底间的界面性质与沉积粒子的性质、能量等因素密切相关。本工作利用俄歇电子能谱仪(AES)所测得的俄歇信号时间曲线(AST),俄歇的价带电子跃迁(AVV)图以及俄歇信号相对强度与沉积厚度的相互关系曲线研究和分析银蒸发束(原子、分子、原子团束)、低能(22eV)和较高能(320eV)Ag~+束在室温Si(111)衬底表面上的沉积过程和可能发生的界面反应。实验结果表明:(1) 蒸发沉积时,银在衬底表面上首先是形成均匀的原子层,接着聚集成为小岛,随后才形成为完整的薄膜;(2) 低能(22eV)Ag~+束沉积时,薄膜为均匀的层状结构,也就是说,薄膜的生长方式是以层层生长方式进行的,衬底与薄膜间的界面在所讨论的1nm范围内是未反应的;(3) 高能(320eV)Ag~+束沉积时,在沉积的初始阶段,界面上会发生严重的混杂效应,以致于形成一种银和硅的混合相结构,在此之后,界面混杂才慢慢停止,形成完整的Ag薄膜。     

CdTe介质膜与HgCdTe晶片间界面特性的研究

利用Ａｒ＾＋束溅射沉积技术在ＨｇＣｄＴｅ表面低温生长了ＣｄＴｅ介质薄膜。分别用ＣｄＴｅ介质膜和ＨｇＣｄＴｅ自身阳极氧化膜对ＨｇＣｄＴｅ表面钝化,利用光电导衰退信号波形的拟合,得到了不同表面钝化的ＨｇＣｄＴｅ非平衡载流子表面复合速度。结果表明,ＣｄＴｅ／ＨｇＣｄＴｅ界面质量已超过自身阳极氧化膜／ＨｇＣｄＴｅ界面质量。     

类金刚石薄膜作为HgCdTe红外器件增透膜和钝化膜的研究

采用高频等离子体化学气相色沉积法（ＲＦＣＶＤ）在ＨｇＣｄＴｅ红外器件上沉积类金刚石薄膜，俄歇电子能谱对ＤＬＣ／ＨｇＣｄＴｅ界面分析结果表明类金刚石薄膜中的碳原子对衬底材料影响较小，７０ｎｍ的类金刚石薄膜抑制衬底组份的外扩散，而且具有纯度较高的类金刚石薄膜外表面层，是一种理想的钝化膜材料，红外透射光谱测试结果表明类金刚石薄膜在较宽的波长范围内（４－１２μｍ）具有明显的增透效应。     

氢离子束对Mo-Si多层膜界面改性的研究

为了研究氢离子束轰击Mo-Si多层膜界面的情况，采用氢离子束（能量150eV）轰击Si表面，即Si与Mo之界面。再用Kr离子束溅射刻蚀，并用俄歇电子能谱（AES）分析。实验结果说明氢离子束对Si表面轰击能有效防止界面混杂效应（intermixingeffect）。进而说明这是制备软X射线多层膜反射镜过程中解决界面混杂问题的有效途径。     

基于真空热压扩散法的金刚石/Ti界面生成机制

采用真空热压扩散法在聚晶金刚石表面制备Ti层,探究金刚石表面金属化过程中的界面生成机制。利用扫描电子显微镜和X射线衍射仪,分析了钛层的表面形貌、界面结构和界面间的物相组成,采用能谱仪对界面进行了元素分析,计算了聚晶金刚石与Ti层之间界面的扩散带宽度及生成TiC的化学反应吉布斯自由能变。研究结果表明:在聚晶金刚石表面形成了平整、致密的Ti层,在聚晶金刚石与Ti层界面之间存在C、Ti和Co元素的扩散,在结合界面处产生了一定宽度的元素扩散带,同时在金刚石表面生成了点状TiC。真空热压扩散法实现了金刚石与Ti层的化学结合,可以提高金刚石与Ti层的结合强度。      

Cr/SiO_2界面还原反应研究

利用俄歇电子能谱研究了Cr／SiO2薄膜在热处理过程中的界面扩散反应机理、界面反应动力学过程及界面反应产物。研究结果表明，Cr／SiO2体系的界面还原反应主要是Cr与SiO2的反应，其还原反应产物是CrSix和Cr2O3物种。界面还原反应的速度与反应时间的平方根成正比，其界面还原反应过程受Cr向SiO2层的扩散过程所控制，界面还原反应的表观活化能为72．5kJ／mol（约0．75eV）。     

Investigation on preparation and diffusion barrier properties of W-Ti thin films

An W-10 wt.%Ti alloy target was prepared by the W-Ti ball-milled powders, and W-Ti thin ?lms were deposited by dc magnetron sputtering on Si substrates. Then Cu/W-Ti/Si structures were prepared after Cu films were deposited on the W-Ti/Si structures. The results show that W-Ti alloy has a single phase structure with fine grain size. The structures of W-Ti thin films evolved from an amorphous film to a dual phase structure with bcc W and hcp Ti, followed by W-Ti solid solution with increasing sputtering powers. W-Ti thin ?lms can effectively block against Cu diffusion and maintain good adhesion strength with Cu ?lms at 600 °C. The failure mechanism of the crystal W-Ti films is related to the grain boundary which provides fast diffusion paths for Cu and Si atoms, while the amorphous W-Ti diffusion barrier layer is directly related to the thermal stress and interface reaction.     

Cu-Fe基粉末烧结金刚石复合材料界面结合特性

以Cu-Fe基粉末为基体材料,在真空压力烧结条件下制备了金刚石复合材料。利用扫描电镜、能谱仪、X射线衍射仪等研究粉末与金刚石颗粒界面结合特性。结果表明,930℃、15MPa烧结温度和压力下,烧结胎体中Fe原子向金刚石表面扩散,形成一定厚度的扩散层,并与金刚石中的C发生化学反应生成Cfe15,呈非连续层片状分布于金刚石颗粒表面,实现了金刚石颗粒与金属的化学键结合。     

F原子与Si表面相互作用的动力学研究

采用分子动力学方法模拟了F原子与Si表面相互作用,F原子入射能量分别为0.3,1,3,5,7和9 eV。在模拟过程中,F原子的沉积率与Si表面悬键密度有关,而Si原子的刻蚀率与表面晶格结构破坏程度有关,随着Si原子刻蚀率的增加,样品高度降低。在不同能量F原子作用下,样品Si表面形成Si-F反应层。Si-F反应层的厚度随入射能量的增加而增加,其组成成分对产物有至关重要的影响。     

Growth of diamond films on SiC, WC and cubic BN substrates

The growth morphology of diamond films grown on single crystals of SiC and on sintered WC and cubic BN (CBN) substrates by hot filament assisted chemical vapour deposition was examined using transmission electron microscopy and scanning electron microscopy. Diamond was found to have the form of particles on the substrates of SiC and WC in the initial stage of film growth. Both an amorphous layer and a directly bonded area were seen at the interface. Several orientation relationships, different from the cube/cube relation, were observed in these systems. On the other hand, in the case of diamond films on CBN substrates, the growth morphology of diamond was affected by the surface condition of the substrates. When CBN substrates were polished with a diamond paste before deposition, diamond grew in the form of particles. The growth morphology was changed by ion sputtering of the surface of the substrate from particle growth to uniform film growth. These results are discussed on the basis of lattice mismatch at the interface. This revised version was published online in November 2006 with corrections to the Cover Date.     

金刚石膜上电子束蒸镀Ti/Ni/Au多层膜

经过相图分析提出了CVD金刚石膜上蒸镀Ti/Ni/Au的体系。采用该体系、富氧预处理工艺和电子束真空镀膜方法 ,金刚石膜和多层金属膜之间获得了良好结合强度。研究发现 :富氧预处理对多金属膜和金刚石膜之间的结合强度影响显著。进一步利用俄歇电子能谱 (AES)证实 :C向Ti中扩散层有 15 0nm之多 ,并出现了厚度约为 90nm稳定含量层 ,说明有确定化学比的反应产物生成 ;富氧处理在金刚石膜与Ti金属层之间增加了氧的含量 ,为形成TiO和TiC提供了合适的条件。     

Retarding intermetallic compounds growth of Zn high-temperature solder and Cu substrate by trace element addition

Since the thickness of layers of intermetallic compounds (IMCs) at the joining interface has an apparent effect on the joint reliability, understanding the growth mechanisms of IMCs is important for die-attachment applications. In the present study, the interfacial reaction between elements (Ca, Mn, Cr, and Ti) added to Zn alloys and Cu substrate were investigated in detail, focusing on IMCs grown by isothermal aging at 150 °C. The reaction layers included two types of Cu–Zn IMCs i.e., γ-Cu₅Zn₈ and ε-CuZn₅ phases. The joining interface with trace elements containing Zn solder reduced the growth rate of the IMCs. In particular, the addition of 0.1 wt% Cr to pure Zn solder decreased the growth rate of the IMCs by approximately 50 %. The mechanism we propose assumes that a phase containing the small Cr atoms exists between the solder and ε-CuZn₅, which suppresses the diffusion of metal atoms. To summarize, the Cr additive showed beneficial effects in terms of suppressing the growth of IMCs during the solid-state isothermal aging.     

Growth mechanism of epitaxial CoSi2 on Si and reactive deposition epitaxy of double heteroepitaxial Si/CoSi2/Si

The growth mechanism of epitaxial CoSi₂ was studied using Co/Ti/Si multilayer solid phase reaction. Results showed that phase formation was controlled by diffusion of Co through the growing CoSi_x, although at the early stage of CoSi₂ growth the diffusion of Co could be controlled by a Ti layer. A reactive deposition technique was also evaluated by using a conventional magnetron sputtering system. Results showed that an epitaxial CoSi₂ layer was formed by controlling the Co sputtering rate not to exceed the Co diffusion rate through CoSi_x. However, the surface of CoSi₂ became rough when the deposition rate was much slower than the Co diffusion rate through CoSi_x. The roughness was caused by the formation of CoSi₂ (111) facets at the interface between CoSi₂ and the Si substrate. Si/CoSi₂/Si double heteroepitaxial structures were fabricated when Si and Co were sequentially sputter-deposited on a Si (100) substrate.     

Wetting behaviors and interfacial characteristics of molten AlxCoCrCuFeNi high-entropy alloys on a WC substrate

The wettability of molten AlxCoCrCuFeNi(x is from 0 to 1.5,mol.％)high-entropy alloys(HEA)on a WC substrate was measured using a modified sessile drop method at 1823 K in an argon atmosphere.The wetting behaviors and interfacial characteristics between HEAs and WC were studied.Good wettability with final equilibrium contact angles of 0.5°-4.6° is obtained,and addition of Al deteriorates the wettabil-ity of the HEAs.The wetting of AlxCoCrCuFeNi/WC system can be roughly divided into an initially sharp spreading stage and a subsequent steady-state phase.In the first stage,the adsorption of Cr atoms at the solid-liquid interface primarily contributes to the wetting,and the contact angle drastically reduces.However,both the wetting behavior and interfacial microstructure are determined by the Al content of the HEA in the next stage.For x≤0.5,the wetting is mainly driven by the dissolution of WC,although a few reaction products of(W,Cr)2C are observed.Moreover,an obvious dissolution pit appears at the surface of the substrate.When the Al content of x≥1,the interfacial reaction is dominant in competition with the dissolution of WC,and massive reaction products precipitate at the HEA/WC interface,which leads to the formation of a continuous reaction layer.