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

基本信息

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

项目摘要

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

氮化钛（Tin_y）的特性逐渐从金属变为价值变为价值，然后随着n与Ti的比率增加而变化，从而使TIN_Y对技术应用的两种观点（例如微电路中的扩散障碍物）和基础研究的观点着迷。为了阐明TIN_Y膜的有趣物理特性，必须在TI_Y膜的生长过程中通过原位观测来研究TI和N原子之间的键合特性。然而，尚不完整的TI膜硝化过程中晶体学和电子结构变化的知识尚未完成。为了获得知识，将400 kV的分析和高分辨率传输电子显微镜（TEM）与离子加速器结合在一起，将氮离子（N_2^+）与62 keV植入了100 nm-thick Ti膜中，这些膜在超高的真空中生长在超高真空中，并评估了由填充能量的ravection freptrection Extraction（Rhhigh）。通过…更多配备了电子能量损耗光谱仪的原位观察，以及Rheed和Rheed和电子光谱，以及离散变化的Xα分子轨道计算的结果，揭示了由于N型物质而蒸发的TI膜的晶体学和电子结构的变化。生长的Ti膜由（110）面向的TIH_X和（03 ・5）面向的HCP-TI组成。蒸发的Ti膜的加热最高为350，从而从TIH_X和转换或TIH_X释放到HCP-TI。 a（001）面向的NaC1型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n cp-tirient a（110） - （110）-Erientired Tientirient Tirientiriendtientientirientiriendtientientirientiriendtirientiriendtientientirientiriendtientientientientientirientiriendtientientientientirientired Tirientirient a（O- tih_x。从tiH_x释放h之前，在fcc-ti sublattice的o点中出现了n的出现。由于在N植入早期植入阶段，TIH_X在生长薄膜中生长的区域的等离子兴奋而引起的能量损失峰转移到降低损耗能量，而HCP-TI已逐渐发展的区域的损失能量随着N剂量的增加而逐渐转移到较高的损耗能量。对Mullliken键重叠的分析表明，O位置中N的占领会导致Ti-Ti键减弱和形成Ti-N共价键。较少的