The influence of deposition parameters on the stress evolution of sputter deposited copper

SURFACE & COATINGS TECHNOLOGY

卷:357

Article

Kaub, Tyler¹  Rao, Zhaoxia²  Chason, Eric²  Thompson, Gregory B.¹ 

[1] Univ Alabama, Dept Met & Mat Engn, Tuscaloosa, AL 35401 USA

[2] Brown Univ, Sch Engn, Providence, RI 02912 USA

关键词: Thin film;    Intrinsic stress;    Sputter deposition;    Microstructure;   

DOI  :  10.1016/j.surfcoat.2018.10.059

来源: Elsevier

【 摘 要 】

The growth rate and pressure dependence on the intrinsic stress in sputter deposited Cu thin films has been investigated and compared to a kinetic growth model, which contains both growth and energetic contributions to stress in its description. Since microstructure also has a strong effect on intrinsic growth stress, we have been able to systematically control a fixed grain size over multiple growth conditions spanning 0.012 nm/s to 2.4 nm/s deposition rates and 0.267 Pa to 2.667 Pa pressures using a seed layer prior to film deposition. At high deposition pressures, the stress became more tensile as the growth rate increased. In the low deposition pressure regime, the stress became more tensile with increases in deposition rate until a critical cross-over point where upon further increases in deposition rate resulted in the stress becoming more compressive. This cross-over has been explained in terms of the energetic contributions to the stress and the intrinsic high mobility of Cu to reveal this behavior. The fitting parameters and corresponding stress contributions from the kinetic model were extracted and compared to other films and deposition techniques. Though caution should be used in comparing absolute values, the kinetic model revealed the correct trends in predicting energetic trapping of defects between low and high mobility films as well as similar growth stress values, which are independent of energetic contributions, between sputtering and electrodeposition. These results suggest that the kinetic model shows promise in fitting different materials and deposition techniques intrinsic stress behavior.

【 授权许可】

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