Chemisorption of ALD precursors in and on porous low-k films

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• 作者：P. Verdonck ; ^{verdonck@imec.be} ; A. Delabie ; J. Swerts ; L. Farrell ; M.R. Baklanov ; H. Tielens ; E. Van Besien ; T. Witters ; L. Nyns ; S. Van Elshocht
• 关键词：Low-k ; Thin films ; Atomic layer deposition
• 刊名：Microelectronic Engineering
• 出版年：2013
• 出版时间：June, 2013
• 年：2013
• 卷：106
• 期：Complete
• 页码：81-84
• 全文大小：622 K

文摘

Atomic layer deposition is a promising technique to deposit conformal, nm-thin metal barriers in high-aspect-ratio trenches. However, exactly because of its excellent conformality, the deposition can also occur inside the nanopores of the most advanced low-k materials. In this work, the mechanisms of atomic layer deposition on and in low-k, porous dielectric films were studied, using HfO₂ as a test material. Exhaustive analyses showed firstly that the HfCl₄ precursor penetrated uniformly in the pores throughout a 44 nm thick low-k film. Secondly, it was shown that the pores were sealed as function of precursor size, i.e. there are conditions where the pores became inaccessible for HfCl₄, while the - smaller - H₂O molecules could still penetrate the pores. From these analyses, a deposition model was proposed.