Studies in atomic-scale control of functional titanium nitride thin films by reflection high energy electron diffraction

反射高能电子衍射对功能氮化钛薄膜原子尺度控制的研究

基本信息

批准号：
11650713
负责人：
KASUKABE Yoshitaka
金额：
$ 2.43万
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：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650713/
关键词：
N-implantation Titanium nitride hcp-fcc transformation reflection high energy electron diffraction in-situ observation transmission electron microscopy molecular orbital calculations electron energy loss spectroscopy 蒸着チタン薄膜

项目摘要

Titanium nitride, TiN, has covalent as well as metallic and ionic properties, which make it fascinating for both technological applications such as diffusion barriers in microcircuits, and fundamental research. In order to investigate the interesting physical properties of TiN films, in-situ observations of the growth of TiN films are more feasible. Although it has been recently reported in light of ex-situ experiments that TiN films could be epitaxially grown by N-implantation into Ti films evaporated on NaCl substrates at room temperature, knowledge of changes in the crystallographic and electronic structures during nitriding Ti films, is incomplete. Thus, nitrogen ions (N_2^+) with 62 keV were implanted into evaporated-Ti films in the 400 kV analytical and high resolution transmission electron microscopy (TEM) combined with ion accelerators. Observations by in-situ TEM equipped with electron energy loss spectroscopy and reflection high energy electron diffraction, along with the discrete variational Xα molecular orbital calculations, revealed changes in the crystallographic and electronic structures of evaporated-Ti films due to N-implantation. A (001)-oriented NaCl-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 occurs preferentially rather than the occupation of N in the O-sites of fcc-Ti sublattice. The loss peak due to volume plasmon of areas where TiH_x has grown in the as-grown Ti film shifts to lower loss energy in the early N-implanting stage, while that of areas, where hcp-Ti has grown, gradually shifts to higher loss energies with increasing N dose. Analysis of Mulliken bond overlap populations determines that occupation of N in the O-sites gives rise to weakening Ti-Ti bonds and formation of Ti-N covalent bonds.

氮化钛锡具有共价和金属和离子性能，这使得它对这两种技术应用都令人着迷，例如微电路中的扩散屏障和基础研究。为了研究锡膜的有趣物理特性，对锡膜生长的现场观察更为可行。尽管最近据据据据称实验报道了锡膜可以通过在室温下在NaCl底物上蒸发在NaCl底物上的Ti膜上外上内外生长的TIN膜，但了解硝化物Ti膜期间晶体学和电子结构的变化的了解，这是不完整的。在400 kV分析和高分辨率的透射电子显微镜（TEM）中，将带有62 keV的氮离子（N_2^+）植入了与离子加速器的400 kV分析和高分辨率透射电子显微镜（TEM）中。配备了电子能损耗光谱和反射高能电子衍射，以及离散的变异Xα分子轨道计算的观测，揭示了由于N-植入植入而导致的蒸发TI膜的晶体和电子结构的变化。 A（001）面向的NaCl-type TIN_Y是通过（03 5）面向（03 5）面向（001）面向（001）面向的FCC-TI的FCC-TI的转换形成的，并且是由八人体内（O-）占用N（O-）的N（110）A（110）A（110） - 方向的niTiend A（110）A（110）A（110）A（110）。 tih_x。从TIH_X释放H的释放更优选地发生，而不是FCC-TI Sublattice的O位置中N的出现。由于ti膜增长的TIH_X在早期植入阶段增长的tiH_x在生长中生长的区域的损耗峰转移到降低损耗能量，而HCP-TI的损失膜则逐渐增长，而HCP-TI的损失能量随着N剂量的增加而逐渐转移到较高的损失能量。对Mullliken键重叠种群的分析确定，O位置中N的发生会导致Ti-Ti键减弱和Ti-N共价键的形成。