Abstract
The interfacial layer (IL) formed at the HfO2/Si interface was investigated by using Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Differently with the previous reports, it is concluded that the inner oxygen from bulk film predominates the oxidation process in interface region rather than the oxygen introduced from outer environment. First, from FT-IR, it is found that the formation of the IL strongly relies on the annealing temperature but does not obviously rely on the HfO2 thickness and the annealing atmosphere. Second, the contradistinctive images of Hf/Si annealed in oxygen ambient and Hf/SiO2 annealed in vacuum were investigated by TEM, which confirms the conclusion obtained from FT-IR data that the IL is formed not by a diffusion of the oxygen from the annealing atmosphere, but by a reaction within the interface region. Third, the Hf 4f, O 1s, and Si 2p core-level energy states of Hf/SiO2 stack annealed in vacuum were investigated by XPS using two ways, one is investigating the samples annealed in vacuum for varied time and the other is investigating the fully oxidized sample in different depth. Based on the experiments, it is concluded that the inner oxygen from bulk films (HfO2 or SiO2) has greater influence on the IL formation comparing with the outer oxygen from environment.
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References
Stathis JH, DiMaria DJ (1998) Tech Dig Int Electron Devices Meet 167
Wilk GD, Wallace RM, Anthony JM (2001) J Appl Phys 89:5243
Joo MS, Cho BJ, Yeo CC, Wu N, Yu H, Zhu C, Li MF, Kwong D-L, Balasubramanian N (2003) Jpn J Appl Phys 42:220
Emotoa T, Akimoto K, Yoshida Y, Ichimiya A, Nabatame T, Toriumi A (2005) Appl Surf Sci 244:55
Yamamoto K, Hayashi S, Kubota M, Niwa M (2002) Appl Phys Lett 81:2053
Cho M-H, Moon DW, Park SA, Kim YK, Jeong K, Kang SK, Ko D-H, Doh SJ, Lee JH, Lee I (2004) Appl Phys Lett 84:5243
Gougousi T, Parsons GN (2004) J Appl Phys 95:1391
Lau WS (1999) Infrared characterization for microelectronics. World Scientific, Singapore
Miyata N et al (2003) JJAP 42:L138
Wang SJ, Lim PC, Huan ACH, Liu CL, Chai JW, Chow SY, Pan JS, Li Q, Ong CK (2003) Appl Phys Lett 82:2047
Vincent BC (2000) Handbook of monochromatic XPS spectra. Wiley, New York
Jeon TS, White JM, Kwong DL (2001) Appl Phys Lett 78:368
Chang JP, Yin YS (2001) Appl Phys Lett 79:3824
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Jiang, R., Xie, E.Q. & Wang, Z.F. Effect of inner oxygen on the interfacial layer formation for HfO2 gate dielectric. J Mater Sci 42, 7343–7347 (2007). https://doi.org/10.1007/s10853-007-1584-z
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DOI: https://doi.org/10.1007/s10853-007-1584-z