Electroless copper deposition as a seed layer on TiSiN barrier
Ee, Elden Yong Chiang
See, K. H.
Law, S. B.
Date of Issue2004
School of Materials Science and Engineering
Electroless deposition of copper as a seeding technology has received considerable attention in back-end-of-line device fabrication. This work explores the effects of plasma processing parameters such as argon gas flow rate and nitrogen plasma treatment time on the properties of electrolessly plated Cu on TiSiN barrier layers. The barrier film was produced by a low-frequency inductively coupled plasma process. The properties of deposited electroless copper are characterized by x-ray diffraction, four-point resistivity probe, atomic force microscopy, and field emission scanning electron microscope. The required palladium activation time is greatly reduced on TiSiN compared to TiN. In both cases there exists a preferred (111) crystal orientation in Cu film and the intensity ratio of I(111)/I(200) is very close. The Cu grain size is within the range of 23–34 nm for 84 nm thick film. It is found that argon gas flow rate does not have a significant effect on the resistivity of electroless copper film on TiSiN. However, increasing nitrogen plasma treatment time reduces the resistivity of copper film. The roughness of plated Cu layer largely follows the one of the underlying TiSiN. Good surface coverage of electroless Cu seed layer on TiSiN has been achieved in our experiment.
Journal of vacuum science & technology A
© 2004 American Vacuum Society. This paper was published in Journal of Vacuum Science & Technology A and is made available as an electronic reprint (preprint) with permission of American Vacuum Society. The paper can be found at the following official URL: http://dx.doi.org/10.1116/1.1738658. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.