Effectiveness of reactive sputter-deposited Ta-N films as diffusion barriers for Ag metallization

被引:12
作者
Adams, D
Malgas, GF
Theodore, ND
Gregory, R
Kim, HC
Misra, E
Alford, TL
Mayer, JW
机构
[1] Univ Western Cape, Dept Phys, ZA-7535 Bellville, South Africa
[2] Motorola Inc, Digital DNA Labs, Tempe, AZ 85284 USA
[3] Arizona State Univ, Dept Chem & Mat Engn, Tempe, AZ 85287 USA
来源
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B | 2004年 / 22卷 / 05期
基金
美国国家科学基金会; 新加坡国家研究基金会;
关键词
D O I
10.1116/1.1787521
中图分类号
TM [电工技术]; TN [电子技术、通信技术];
学科分类号
0808 ; 0809 ;
摘要
Tantalum nitride films on silicon were prepared by reactive sputtering of Ta under nitrogen partial 4 flow rates varying from 15% to 40% N-2. Rutherford backscattering spectroscopy (RBS) and x-ray diffraction (XRD) analysis revealed that the composition and phases of the Ta-N films were influenced by the N2 flow rate. Increasing the nitrogen partial flow rate from 25% to 40% N-2, results in the films changing from metal-rich to stoichiometric Ta-nitride. High N-2 flow rates (30%-40% N-2) resulted in a disordered tantalum-nitride. The tantalum nitride films were evaluated as potential diffusion barriers for Ag metallization. Sheet resistance measurements, XRD and RBS analysis confirmed that Ta-N films, used as diffusion barriers in the Ag/Ta-N/Si system, were thermally stable up to 650 degreesC when annealed for 30 min in vacuum. The thermal stability was independent of N-2, flow rate within this temperature range. However, at 700 degreesC, the barrier failed as a result of Ta-silicide formation by reaction with the underlying Si substrate, and dewetting of Ag on Ta-N occurred. (C) 2004 American Vacuum Society.
引用
收藏
页码:2345 / 2352
页数:8
相关论文
共 37 条