Effects of additive C{sub 4}F{sub 8} during inductively coupled BCl{sub 3}/C{sub 4}F{sub 8}/Ar plasma etching of TaN and HfO{sub 2} for gate stack patterning
- School of Advanced Materials Science and Engineering, and Center for Advanced Plasma Surface Technology, Sungkyunkwan University, Suwon, Kyunggi-do 440-746 (Korea, Republic of)
In this work, the authors investigated the etching characteristics of TaN and HfO{sub 2} layers for gate stack patterning in BCl{sub 3}/Ar and BCl{sub 3}/C{sub 4}F{sub 8}/Ar inductively coupled plasmas and the effects of C{sub 4}F{sub 8} addition on the etch selectivity of the TaN to the HfO{sub 2} layer. Addition of C{sub 4}F{sub 8} gas to the BCl{sub 3}/Ar chemistry improved the TaN/HfO{sub 2} etch selectivity because adding the C{sub 4}F{sub 8} gas enhances the formation of the CF{sub x}Cl{sub y} passivation layer on HfO{sub 2} surface and decreased the HfO{sub 2} etch rate more rapidly than the TaN etch rate in a disproportionate way. Reduction in the etch time for HfO{sub 2} layer also increases the TaN/HfO{sub 2} etch selectivity because the etch time gets closer to the initiation time for HfO{sub 2} etching.
- OSTI ID:
- 20979513
- Journal Information:
- Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Vol. 25, Issue 4; Other Information: DOI: 10.1116/1.2747621; (c) 2007 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1553-1813
- Country of Publication:
- United States
- Language:
- English
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