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Electron Energy Loss Spectroscopy Characterization of TANOS (TaN/Al2O3/Si3N4/SiO2/Si) Stacks

Published online by Cambridge University Press:  06 August 2013

Jucheol Park*
Affiliation:
Center for Materials Analysis, Research Institute for Advanced Materials, Seoul National University, 599 Gwanangno, Gwanak-gu, Seoul 151-742, Korea
Sung Heo
Affiliation:
AE Group, Samsung Advanced Institute of Technology, Nongseo-Dong Mt.14-1, Giheung-gu, Yongin-si, Gyeonggi-do 446-712, Korea
JaeGwan Chung
Affiliation:
AE Group, Samsung Advanced Institute of Technology, Nongseo-Dong Mt.14-1, Giheung-gu, Yongin-si, Gyeonggi-do 446-712, Korea
Gyeong-Su Park
Affiliation:
AE Group, Samsung Advanced Institute of Technology, Nongseo-Dong Mt.14-1, Giheung-gu, Yongin-si, Gyeonggi-do 446-712, Korea
*
*Corresponding author. E-mail: jucheolpark@snu.ac.kr
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Abstract

The interfacial layer between the Al2O3 layer and the Si3N4 layer formed after postdeposition annealing (PDA) of TaN/Al2O3/Si3N4/SiO2/Si (TANOS) stacks was investigated using transmission electron microscopy (TEM), scanning transmission electron microscopy, and electron energy loss spectroscopy (EELS). From the result of the TEM analysis, it was found that the 2-nm-thick interface layer between Al2O3 and Si3N4 layers was amorphous. The high-loss EELS analysis showed that the phases of the interfacial layer weakly bound together instead of the substoichiometric silicon oxide and amorphous Al2O3 near the bottom interface of the crystalline Al2O3. The low-loss EELS analysis showed that aluminum existed in metallic state at the interface. Therefore, we speculated that SiOxNy could be formed by oxidation of Si3N4 during PDA and that metallic aluminum could be formed by the decomposition of weakly bound amorphous Al2O3 during electron irradiation. These complicated reactions near the interface could induce oxygen deficiency in the Al2O3 layer and finally degrade the retention properties of TANOS stacks.

Type
Research Article
Copyright
Copyright © Microscopy Society of America 2013 

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References

Balzarotti, A., Antonangeli, F., Girlanda, R. & Martino, G. (1982). Core excitons in corundum. Solid State Commun 44, 275278.Google Scholar
Batson, P.E. (1991). Current trends for EELS studies in physics. Microsc Microanal Microstruct 2, 395402.Google Scholar
Bouchet, D. & Colliex, C. (2003). Experimental study of ELNES at grain boundaries in alumina: Intergranular radiation damage effects on Al-L23 and O-K edges. Ultramicroscopy 96, 139152.10.1016/S0304-3991(02)00437-0Google Scholar
Chang, M., Ju, Y., Lee, J., Jung, S., Choi, H., Jo, M., Jeon, S. & Hwang, H. (2008). Impact of oxygen incorporation at the Si3N4/Al2O3 interface on retention characteristics for nonvolatile memory applications. Appl Phys Lett 93, 2210122103.Google Scholar
Harp, G.R., Han, Z.L. & Tonner, B.P. (1990). Spatially-resolved X-ray absorption near-edge spectroscopy of silicon in thin silicon-oxide films. Physica Scripta T31, 2327.10.1088/0031-8949/1990/T31/003Google Scholar
Hunt, E.M., Wang, Z.L., Evans, N.D. & Hampikian, J.M. (1998). High-spatial resolution compositionally-sensitive imaging of metallic particles using plasmon energy-loss electrons in TEM. Micron 29, 191199.10.1016/S0968-4328(97)00056-5Google Scholar
Jeon, S., Han, J.H., Lee, J.H., Choi, S.M., Hwang, H.S. & Kim, C.W. (2005). High work-function metal gate and high-k dielectrics for charge trap flash memory device applications. IEEE Trans Electron Devices 52(12), 26542659.10.1109/TED.2005.859691Google Scholar
Kimoto, K., Matsui, Y., Nabatame, T., Yasuda, T., Mizoguchi, T., Tanaka, I. & Toriumi, A. (2003). Coordination and interface analysis of atomic-layer-deposition Al2O3 on Si(001) using energy-loss near-edge structures. Appl Phys Lett 83, 43064308.Google Scholar
Kimoto, K., Sekiguchi, T. & Aoyama, T. (1997). Chemical shift mapping of Si L and K edges using spatially resolved EELS and energy-filtering TEM. J Electron Microsc 46(5), 369374.10.1093/oxfordjournals.jmicro.a023532Google Scholar
Lisiansky, M., Heiman, A., Kovler, M., Fenigstein, A., Roizin, Y., Levin, I., Gladkikh, A., Oksman, M., Edrei, R., Hoffman, A., Shnieder, Y. & Claasen, T. (2006). SiO2/Si3N4/Al2O3 stacks for scaled-down memory devices: Effects of interfaces and thermal annealing. Appl Phys Lett 89, 153506153508.10.1063/1.2360197Google Scholar
Park, J.K., Park, Y., Lim, S.K., Oh, J.S., Joo, M.S., Hong, K. & Cho, B.J. (2010). Improvement of memory performance by high temperature annealing of the Al2O3 blocking layer in a charge-trap type flash memory device. Appl Phys Lett 96, 222902.10.1063/1.3442502Google Scholar
Rothschild, A., Breuil, L., Van Den Bosch, G., Richard, O., Conard, T., Franquet, A., Cacciato, A., Debusschere, I., Jurczak, M., Van Houdt, J., Kittl, J.A., Ganguly, U., Date, L., Boelen, P. & Schreutelkamp, R. (2009). O2 post deposition anneal of Al2O3 blocking dielectric for higher performance and reliability of TANOS Flash memory. In Proc. ESSDERC 2009, pp. 272275, Athens.Google Scholar
Stöckli, T., Bonard, J.-M., Stadelmann, P.-A. & Châtelain, A. (1997). EELS investigation of plasmon excitations in aluminum nanospheres and carbon nanotubes. Z Phys D 40, 425428.Google Scholar
Tan, Y.N., Wen, H.C., Park, C., Gilmer, D.C., Young, C.D., Heh, D., Sivasubramani, P., Huang, J., Majhi, P., Kirsch, P.D., Lee, B.H., Tseng, H.H. & Jammy, R. (2008). Tunnel oxide dipole engineering in TANOS flash memory for fast programming with good retention and endurance. In International Symposium on VLSI Technology, Systems, and Applications, pp. 5455. Hsinchu: IEEE Electron Devices Society.Google Scholar
Tanaka, I. & Adachi, H. (1996). Calculation of core-hole excitonic features on Al L 2,3-edge X-ray-absorption spectra of α-Al 2O 3. Phys Rev B54, 46044608.10.1103/PhysRevB.54.4604Google Scholar
Ziegler, A., Idrobo, J.C., Cinibulk, M.K., Kisielowski, C., Browning, N.D. & Ritchie, R.O. (2004). Interface structure and atomic bonding characteristics in silicon nitride ceramics. Science 306, 17681770.10.1126/science.1104173Google Scholar