TiN with Multilayered Structure and TaN as Diffusion Barrier for Cu Metallization

• Main Authors: Huang, Chi-Feng, 黃麒峰
• Other Authors: Wu, Shinn-Tyan
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/73873275818937053580

碩士 === 國立清華大學 === 材料科學工程研究所 === 88 === 　　In this research,a novel multilayered Ti/TiN diffusion barrier was proposed applied to Cu metallization. TiN film displays columnar structure after PVD sputtering, and the grain boundaries between two columnar grains become fast diffusion path and hence result in the interdiffusion between metal and silicon. We try to destroy the continuity of columnar structure of TiN by inserting one or more Ti layers. Effects of Ti inserting layers were invested. 　　From TEM analyses, it was found that continuity of columnar grain was destroyed while a Ti layer was inserted in TiN, Multilayered Ti/TiN enhance teh thermal stability and has better barrier performance than single TiN layer from junction leakage current analyses. It was found that the more Ti layers, the more improvement of barrier performance. However, the improvement was not very obvious as the thickness of Ti layers were too thin. In this research we also discuss the effect of oxygen content in TiN thin film. Oxygen contnts in grain boundaries contributed to the amorphous microstructure, and hence improve the barrier performance. 　　On the other hand, tantalum nitride was reactively sputtered by various nitrogen/argon flow ratios. It was found that microstructure of tantalum nitride become more and more amorphous with increasing nitrogen flow ratio, It was found that TaN deposited at high nitrogen flow ratio has better barrier performance from junction leakage current analyses.