High resolution and energy filtering TEM study of interfacial structure and reaction in advanced materials processing

Holin Chang*, Li Chang, Fu Rong Chen, J. J. Kai, Eugene Tzou, Jianming Fu, Zheng Xu, J. Egermeier, Fu Sen Chen

*Corresponding author for this work

研究成果: Article同行評審

7 引文 斯高帕斯(Scopus)

摘要

High resolution TEM becomes more powerful when coupled with a Gatan imaging filter (GIF). It gives both structural and compositional information simultaneously with subnanometer and nanometer resolution, respectively. By means of these combined techniques, the failure mechanism of diffusion barrier layers in IC devices, having the structure of Al-1%Si-0.5%Cu/TiN/Ti/Si substrate, was investigated. In non-oxygen stuffed samples thermally stressed at 550°C for 1 h, serious Al spikes below contacts were observed where metal layer Ti also reacted with Si substrate to form C49-TiSi2 and was consumed completely. TiN and Al become unstable due to high temperature thermal stress and reacted into TiAl3 and AlN. Decomposition of TiN degraded the function of the barrier layer, and so a diffusion path at the weakest point of the contact corner was opened for metal Al alloy to diffuse through the barrier layer and to form a spike below the TiN layer. We also showed that the oxygen-stuffing processes after each TiN/Ti deposition enhances the barrier capability against Al/Si diffusion in thermal stress. It was found that Ti and TiN were oxidized to form titanium oxide which reacted with the Al alloy. As a result, Al2O3 and TiAl3 were found above the TiN layer. Therefore, it is concluded that oxidation during oxygen-stuffing processes provides a means to inhibit diffusion in thermal stress processes, and maintains integrity of the stack structure.

原文English
頁(從 - 到)2431-2439
頁數9
期刊Acta Materialia
46
發行號7
DOIs
出版狀態Published - 10 四月 1998

指紋 深入研究「High resolution and energy filtering TEM study of interfacial structure and reaction in advanced materials processing」主題。共同形成了獨特的指紋。

引用此