標題: Barrier capability of HfN films with various nitrogen concentrations against copper diffusion in CuHf-N/n(+)-p junction diodes
作者: Ou, KL
Chiou, SY
Lin, MH
Hsu, RQ
機械工程學系
Department of Mechanical Engineering
公開日期: 2005
摘要: Hafnium-based (Hf-N) films were prepared by reactive radio frequency (rf)-magnetron sputtering on blank silicon wafers. Nitrogen incorporation and phase transformation of hafnium-based thin film were analyzed by cross-sectional transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The as-deposited Hf film has a hexagonal close-packed structure and a low resistivity of 48.29 muOmega cm. With increasing nitrogen concentration of Hf-N film, phase transformations are identified as alpha-Hf --> HfN0.4 --> epsilon-Hf3N2 --> fcc-HfN. The thermal stability of the Cu/Hf-N/Si contact system is evaluated by thermal stressing at various annealing temperatures. For the Cu/Hf/Si contact system, the inter-facial reaction between the Hf barrier layer and the Cu layer is observed after annealing at 550degreesC for 30 min, and copper-hafnium compounds form. Highly resistive copper silicide forms after annealing at 600degreesC for 30 min. The Elf barrier fails due to the reaction of Cu and the Hf barrier, in which Cu atoms penetrate into the Si substrate after annealing at high temperature. However, no copper-hafnium and copper silicide compounds are found for the Cu/HfN0.47/Si contact system even after annealing at 650degreesC for 30 min. A hafnium diffusion barrier incorporated with nitrogen can suppress the formation of copper-hafnium compounds and copper penetration, and thus enhance the thermal stability of the barrier layer. (C) 2005 The Electrochemical Society.
URI: http://hdl.handle.net/11536/25433
http://dx.doi.org/10.1149/1.1850367
ISSN: 0013-4651
DOI: 10.1149/1.1850367
期刊: JOURNAL OF THE ELECTROCHEMICAL SOCIETY
Volume: 152
Issue: 2
起始頁: G138
結束頁: G143
Appears in Collections:Articles


Files in This Item:

  1. 000227142400065.pdf