Investigation of aluminum film properties and microstructure for replacement metal gate application
| Autor: | J. Y. Wu, Chi-Mao Hsu, C. L. Yang, H. K. Hsu, Welch Lin, Teng-Chun Tsai, R. P. Huang, J. F. Lin, Hung-Chin Huang, M. C. Tsai |
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| Rok vydání: | 2013 |
| Předmět: |
Materials science
Metallurgy chemistry.chemical_element Pinhole Condensed Matter Physics Microstructure Atomic and Molecular Physics and Optics Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry Aluminium Chemical-mechanical planarization Physical vapor deposition Electrical and Electronic Engineering Composite material Metal gate Wetting layer High-κ dielectric |
| Zdroj: | Microelectronic Engineering. 106:56-62 |
| ISSN: | 0167-9317 |
| Popis: | The fundamental film properties and micro-structures of the different aluminum (Al) metal layers are evaluated to fabricate a replacement metal gate (RMG) device for the high-k metal gate (HKMG) application at 28nm node. A PVD Al fill-in metal deposition process, called one step hot Al (HAL), was found the resistivity increases with increasing the thickness of the Ti wetting layer. The higher pinhole density with the preferred (111) crystal orientation in the HAL layers indicate the film properties with lower reflectivity, higher resistivity and lower removal rate of the Al chemical mechanical polishing (AlCMP). In contrast, the other PVD Al deposition approach, called two steps cold hot Al (CHAL), was identified to possess lower resistivity and higher reflectivity without pinhole structures than the HAL. The smaller grain sizes with the preferred (220) orientation in the CHAL could effectively prevent the formation of pinhole and enhance the removal rate of the AlCMP. The non-uniform with crystallized TiAl"3 phase detected in the bottom of the as-deposited HAL and CHAL films could obviously impact the removal rate of the AlCMP. An optimized CHAL fill-in metal deposition process with a larger than 40A Ti wetting layer are needed to simultaneously meet the process requirements of the Al gapfill and AlCMP planarization for achieving a reliable RMG structures. |
| Databáze: | OpenAIRE |
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