Fabrication of Al2O3/Al structure by nitric acid oxidation at room temperature

• Authors: Takashi Iwata , Taketoshi Matsumoto , Sumio Terakawa , Hikaru Kobayashi
• Languages of publication: EN

Abstracts

EN

A thick Al2O3/aluminum (Al) structure has been fabricated by oxidation of Al with 68wt% and 98wt% nitric acid (HNO3) aqueous solutions at room temperature. Measurements of the Al2O3 thickness vs. the oxidation time show that reaction and diffusion are the rate-determining steps for oxidation with 68wt% and 98wt% HNO3 solutions, respectively. Observation of transmission electron micrographs shows that the Al2O3 layer formed with 68wt% HNO3 has a structure with cylindrically shaped pores vertically aligned from the Al2O3 surface to the Al2O3/Al interface. Due to the porous structure, diffusion of HNO3 proceeds easily, resulting in the reaction-limited oxidation mechanism. In this case, the Al2O3/Al structure is considerably rough. The Al2O3 layer formed with 98wt% HNO3 solutions, on the other hand, possesses a denser structure without pores, and the Al2O3/Al interface is much smoother, but the thickness of the Al2O3 layer formed on crystalline Al regions is much smaller than that on amorphous Al regions. Due to the relatively uniform Al2O3 thickness, the leakage current density flowing through the Al2O3 layer formed with 68wt% HNO3 is lower than that formed with 98wt% HNO3.

Keywords

EN

nitric acid oxidation; aluminum oxide; MOS; gate insulator

• Publisher: De Gruyter Open
• Journal: Open Physics
• Year: 2010
• Volume: 8
• Issue: 6
• Pages: 1015-1020

Dates

published

1 - 12 - 2010

online

5 - 9 - 2010

Contributors

author

Takashi Iwata

• Institute of Scientific and Industrial Research, Osaka University and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan

author

Taketoshi Matsumoto

• Institute of Scientific and Industrial Research, Osaka University and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan

author

Sumio Terakawa

• Institute of Scientific and Industrial Research, Osaka University and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan

author

Hikaru Kobayashi

• Institute of Scientific and Industrial Research, Osaka University and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan

References

• [1] N. Y. Yakovleva et al., Thin Solid Films 416, 16 (2002) http://dx.doi.org/10.1016/S0040-6090(02)00625-9[Crossref]
• [2] H.-H. Shin, S.-L. Tzou, Surf. Coat. Tech. 124, 278 (2000) http://dx.doi.org/10.1016/S0257-8972(99)00646-5[Crossref]
• [3] E. J. Markel, E. Reddick, L. A. Napper, J. W. Van Zee, J. Non-Cryst. Solids 180, 32 (1994) http://dx.doi.org/10.1016/0022-3093(94)90394-8[Crossref]
• [4] K.-C. Chuang, J.-G. Hwu, Appl. Phys. Lett. 89, 232903 (2006) http://dx.doi.org/10.1063/1.2402215[Crossref]
• [5] J.-C. Chiang, J.-W. Hwu, Appl. Phys. Lett. 90, 102902 (2007) http://dx.doi.org/10.1063/1.2711290[Crossref]
• [6] Asuha et al., Appl. Phys. Lett. 81, 3410 (2002) http://dx.doi.org/10.1063/1.1517723[Crossref]
• [7] H. Kobayashi, Asuha, O. Maida, M. Takahashi, H. Iwasa, J. Appl. Phys. 94, 7328 (2003) http://dx.doi.org/10.1063/1.1621720[Crossref]
• [8] Asuha, Y.-L. Liu, O. Maida, M. Takahashi, H. Kobayashi, J. Electrochem. Soc. 151, G824 (2004) http://dx.doi.org/10.1149/1.1809594[Crossref]
• [9] W.-B. Kim, T. Matsumoto, H. Kobayashi, J. Appl. Phys. 105, 103709 (2009) http://dx.doi.org/10.1063/1.3130596[Crossref]
• [10] Asuha, S. Imai, M. Takahashi, H. Kobayashi, Appl. Phys. Lett. 85, 3783 (2004) http://dx.doi.org/10.1063/1.1804255[Crossref]
• [11] Asuha et al., Surf. Sci. 600, 2523 (2006) http://dx.doi.org/10.1016/j.susc.2006.04.015[Crossref]
• [12] S. Imai, S. Mizushima, Asuha, W.-B. Kim, H. Kobayashi, Appl. Surf. Sci. 254, 3685 (2008) http://dx.doi.org/10.1016/j.apsusc.2008.03.025[Crossref]
• [13] S. Imai, M. Fujimoto, Asuha, M. Takahashi, H. Kobayashi, Surf. Sci. 600, 547 (2006) http://dx.doi.org/10.1016/j.susc.2005.11.005[Crossref]
• [14] M. Takahashi, S.-S. Im, M. Madani, H. Kobayashi, J. Electrochem. Soc. 155, H47 (2008) http://dx.doi.org/10.1149/1.2804769[Crossref]
• [15] S.-S. Im, S. Terakawa, H. Iwasa, H. Kobayashi, Appl. Surf. Sci. 254, 3667 (2008) http://dx.doi.org/10.1016/j.apsusc.2007.10.102[Crossref]
• [16] B. R. Strohmeier, Surf. Interface Anal. 15, 51 (1990) http://dx.doi.org/10.1002/sia.740150109[Crossref]
• [17] S. Thomas, P. M. A. Sherwood, J. Chem. Soc. Faraday T. 89, 263 (1993) http://dx.doi.org/10.1039/ft9938900263[Crossref]
• [18] M. Textor, R. Grauer, Corros. Sci. 23, 41 (1983) http://dx.doi.org/10.1016/0010-938X(83)90058-6[Crossref]
• [19] W. M. Mullins, B. L Averbach, Surf. Sci. 206, 52 (1988) http://dx.doi.org/10.1016/0039-6028(88)90014-3[Crossref]
• [20] S. Tanuma, C. J. Powell, D. R. Penn, Surf. Interface Anal. 11, 577 (1988) http://dx.doi.org/10.1002/sia.740111107[Crossref]
• [21] S. Iwata, A. Isizuka, J. Appl. Phys. 79, 6653 (1996) http://dx.doi.org/10.1063/1.362676[Crossref]
• [22] H. Kobayashi, T. Kubota, H. Kawa, Y. Nakato, M. Nishiyama, Appl. Phys. Lett. 73, 933 (1998) http://dx.doi.org/10.1063/1.122042[Crossref]
• [23] C. Ocal, B. Basurco, S. Ferrer, Surf. Sci. 157, 233 (1985) http://dx.doi.org/10.1016/0039-6028(85)90645-4[Crossref]
• [24] S. M. Sze, VLSI Technology, International Student Edition (McGraw-Hill, Singapore, 1984) ch. 4
• [25] J. Rovertson, J. Non-Cryst. Solids 303, 94 (2002) http://dx.doi.org/10.1016/S0022-3093(02)00972-9[Crossref]
• [26] D. T. Clark, K. C. Tripathi, Nature. Physical science 244, 77 (1973) http://dx.doi.org/10.1038/244077a0[Crossref]
• [27] B. R. Strohmeier, Surf. Interface Anal. 15, 51 (1990) http://dx.doi.org/10.1002/sia.740150109[Crossref]

Identifiers

DOI

10.2478/s11534-010-0014-z