Studies in highly-developed functionalizing of titanium nitride thin films by reflection high energy electron diffraction and electron spectroscopy

通过反射高能电子衍射和电子能谱研究高度发达的氮化钛薄膜功能化

• 批准号: 13650730
• 负责人: KASUKABE Yoshitaka
• 金额: $ 2.24万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650730/
• 关键词: N-implantation; Titanium nitride; hcp-fcc transformation; reflection high energy electron diffraction; Auger electron spectroscopy; transmission electron microscopy; electron energy loss spectroscopy; molecular orbital calculations; hc-fcc構造変態

The property of titanium nitride, TiN_y, gradually changes from metallic to covalent and then to ionic with increasing the ratio of N to Ti, which makes TiN_y fascinating for both points of view of technological applications such as diffusion barriers in microcircuits and fundamental research. In order to elucidate the interesting physical properties of TiN_y films, investigation of bonding properties between Ti and N atoms by in-situ observations during the growth of TiN_y films is necessary. However, knowledge of changes in the crystallographic and electronic structures during nitriding of Ti films, is not complete yet. Thus, to obtain the knowledge, in the 400 kV analytical and high resolution transmission electron microscope (TEM) combined with ion accelerators, nitrogen ions (N_2^+) with 62 keV were implanted into 100 nm-thick Ti films, which were grown in ultra-high vacuum with evaluation of the crystallinity by reflection high energy electron diffraction (RHEED). Observations by … More in-situ TEM equipped with electron energy loss spectrometer and by RHEED and Auger electron spectroscopy, along with the results of the discrete variational Xα molecular orbital calculations, revealed changes in the crystallographic and electronic structures of evaporated-Ti films due to N-implantation. As-grown Ti films consist of (110)-oriented TiH_x and (03・5)-oriented hcp-Ti. Heating of evaporated Ti films up to 350℃ gives rise to release of H from TiH_x and transformation or TiH_x to hcp-Ti. A (001)-oriented NaC1-type TiN_y is epitaxially formed by the transformation of (03・5)-oriented hcp-Ti to (001)-oriented fcc-Ti and by the occupation of N in the octahedral (O-) sites, whereas a (110)-oriented TiN_y is formed by nitriding a (110)-oriented TiH_x. The release of H from the TiH_x precedes the occupation of N in the O-sites of fcc-Ti sublattice. The energy loss peak due to plasmon excitation of the areas where TiH_x has grown in the as-grown films shifts to lower loss energy in the early N-implanting stage, while that of the areas, where hcp-Ti has grown, gradually shifts to higher loss energies with increasing N-dose. Analysis of Mulliken bond overlap populations revealed that occupation of N in the O-sites gives rise to weakening of Ti-Ti bonds and forming of Ti-N covalent bonds. Less

随着氮钛比的增加，氮化钛TiN_y的性质逐渐从金属到共价再到离子，这使得TiN_y在微电路扩散势垒和基础研究等技术应用方面都具有很大的吸引力。为了阐明TiN_y薄膜有趣的物理性质，有必要通过原位观测来研究TiN_y薄膜生长过程中钛原子与N原子之间的成键性质。然而，关于钛薄膜氮化过程中的结晶学和电子结构变化的知识还不完全。为此，在带有离子加速器的400kV分析和高分辨电子显微镜上，用62keV的氮离子注入100 nm厚的钛薄膜，并用反射高能电子衍射(RHEED)分析了薄膜的结晶度。…的观察结果用电子能量损失谱、RHEED和俄歇电子能谱以及离散变分X-α分子轨道计算的结果，揭示了N注入对蒸发钛薄膜的晶体结构和电子结构的影响。生长的钛薄膜由(110)取向的TiHx和(03·5)取向的hcp-Ti组成。蒸发的钛薄膜加热到350℃时，H从TiH_x释放出来，或TiH_x转变为Hcp-Ti。(001)取向的NaCl型TiN_y是通过(03·5)取向的hcp-Ti转变为(001)取向的fcc-Ti而外延形成的，而(110)取向的TiN_y是通过氮化(110)取向的TiH_x而形成的，H从TiH_x中的释放先于N在fcc-Ti亚晶格的O位上的占据。在N注入初期，TiHx生长区域的等离子体激元激发能量损失峰向低损耗能量方向移动，而HCP-Ti生长区域的等离子体激发能量损失峰随N剂量的增加而逐渐向高损耗能量方向移动。Mulliken键重叠布居分析表明，N在O位的占据导致了Ti-Ti键的弱化和Ti-N共价键的形成。较少

项目成果

Y. Kasukabe, Y. Fujino, M. Osaka, Y. Yamada and H. Abe: "In-situ Observation of Growth Processes of Transition Metal Compound Thin Films by Carbon-lmplantation"JAERI-Review. 2001-039. 207-209 (2001)

Y. Kasukabe、Y. Fujino、M. Osaka、Y. Yamada 和 H. Abe：“通过碳注入对过渡金属化合物薄膜的生长过程进行原位观察”JAERI-Review。

Y.Kasukabe: "In-situ Observation of Formation Processes of Titanium Compound Thin Films due to Ion Implantation in A Transmission Electron Microscope"Nuclear Instruments and Methods in Physics Research Section B. 206. 390-394 (2003)

Y.Kasukabe：“在透射电子显微镜中对离子注入导致的钛化合物薄膜形成过程的原位观察”物理研究中的核仪器和方法B.206.390-394（2003）

Y.Kasukabe: "In-situ Observation of Growth Processes of Transition Metal Nitride Thin Films by Nitrogen-Implantation"JAERI-Review. 2002-035. 203-205 (2002)

Y.Kasukabe：“通过氮注入对过渡金属氮化物薄膜的生长过程进行原位观察”JAERI-评论。