AVS 45th International Symposium
    Thin Films Division Wednesday Sessions
       Session TF-WeM

Paper TF-WeM10
Improvement of Morphological Stability of Ag Thin on TiN Layer

Wednesday, November 4, 1998, 11:20 am, Room 310

Session: ULSI Metalization and Interconnects
Presenter: C.-Y. Hong, Massachusetts Institute of Technology
Authors: C.-Y. Hong, Massachusetts Institute of Technology
Y.-C. Peng, National Tsing-Hua University, Republic of China
L.-J. Chen, National Tsing-Hua University, Republic of China
W.-Y. Hsieh, United Microelectronic Corporation, Republic of China
Correspondent: Click to Email
Owing to the need to increase the packing density in ULSI, thermally stable low-resistive contact and metallization technologies are important. Numerous studies of noble-metal-semiconductor processes have been conducted to obtain a better understanding of the interface structure and other properties. Ag is the most conductive materials and has been considered to be a candidate materials for interconnection in ULCI fabrication. Since fast interdiffusion occursbetween Ag and Si substrate, advanced metallization technologies of Ag for ULSI require a highly comformal barrier layer to prevent the interdiffusion between Ag and Si substrate. Among various kinds of diffusion barriers, titanium nitride (TiN) thin films have been widely used in ULSI fabrication due to its relatively low electrical resistivity and high thermal stability. In a previous study, Ag islands were found to form on TiN layers after annealing at 100 °C for 30 min. Owing to the poor morphological stability of the Ag/TiN interface, the utilization of thin Au and Ti layers between Ag and TiN layers has been explored to overcome the island formation problem in this study. The presence of interposing Au and Ti layers was found to increase the morphological stability temperature of Ag thin films on TiN layer from 100 °C to 450 °C and 350 °C, respectively.