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Investigations of Metal Gate Electrodes on HfO2 Gate Dielectrics

  • Jamie Schaeffer (a1), Sri Samavedam (a1), Leonardo Fonseca (a1), Cristiano Capasso (a1), Olubunmi Adetutu (a1), David Gilmer (a1), Chris Hobbs (a1), Eric Luckowski (a1), Rich Gregory (a1), Zhi-Xiong Jiang (a1), Yong Liang (a1), Karen Moore (a1), Darrell Roan (a1), Bich-Yen Nguyen (a1), Phil Tobin (a1) and Bruce White (a1)...

Abstract

As traditional poly-silicon gated MOSFET devices scale, the additional series capacitance due to poly-silicon depletion becomes an increasingly large fraction of the total gate capacitance, excessive boron penetration causes threshold voltage shifts, and the gate resistance is elevated. To solve these problems and continue aggressive device scaling we are studying metal electrodes with suitable work-functions and sufficient physical and electrical stability. Our studies of metal gates on HfO2 indicate that excessive inter-diffusion, inadequate phase stability, and interfacial reactions are mechanisms of failure at source drain activation temperatures that must be considered during the electrode selection process. Understanding the physical properties of the metal gate – HfO2 interface is critical to understanding the electrical behavior of MOS devices. Of particular interest is Fermi level pinning, a phenomenon that occurs at metal – dielectric interfaces which causes undesirable shifts in the effective metal work function. The magnitude of Fermi level pinning on HfO2 electrodes is studied with Pt and LaB6 electrodes. In addition, the intrinsic and extrinsic contributions to Fermi level pinning of platinum electrodes on HfO2 gate dielectrics are investigated by examining the impact of oxygen and forming gas anneals on the work function of platinum-HfO2-silicon capacitors. The presence of interfacial oxygen vacancies or Pt-Hf bonds is believed to be responsible for a degree of pinning that is stronger than predicted from the MIGS model alone. Interface chemistry and defects influence the effective metal work function.

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1 Hori, T., Gate Dielectrics and MOS ULSIs, (Springer 1997).
2 De, I., Johri, D., Srivastava, A., Osburn, C.M., Solid State Electronics, 44 1077 (2000).
3 Cheng, B., Maiti, B., Samavedam, S., Grant, J., Taylor, B., Tobin, P., Mogab, J., 2001 IEEE Intl. SOI Conf., (2001).
4 Gilmer, D.C., Hegde, R., Cotton, R., Garcia, R., Dhandapani, V., Triyoso, D., Roan, D., Franke, A., Rai, R., Prabhu, L., Hobbs, C., Grant, J.M., La, L., Samavedam, S., Taylor, B., Tseng, H., Tobin, P., Appl. Phys. Lett., 81 7 1288 (2002).
5 Hume-Rothery, W., “Atomic Diameters, Atomic Volumes, and Solid Solubility Relations in Alloys”, Acta Metallurgica 14 1720 (1966).
6 Harding, J. H., Interface Science, 11 8190 (2003).
7 Lu, F-H., Newhouse, M.L., Dieckmann, R., Xue, J., Solid State Ionics 75 187192 (1995).
8 Maszara, W.P., Krovokapic, Z., King, P., Goo, J-S., Lin, M-R., 2002 IEDM Tech. Dig. 367370, (2002).
9 Pierson, H., Handbook of Refractory Carbides and Nitrides, (Noyes, 1996)
10 Ranade, P., Takeuchi, H., King, T-J., Hu, C., Electrochem. Sol. State Lett., 4 G85 (2001).
11 Schaeffer, J. K., Samavedam, S. B., Gilmer, D. C., Dhandapani, V., Tobin, P. J., Mogab, J., Nguyen, B-Y., White, B.E. Jr., Dakshina-Murthy, S., Rai, R. S., Jiang, Z-X., Martin, R., Raymond, M. V., Zavala, M., La, L. B., Smith, J. A., Garcia, R., Roan, D., Kottke, M., and Gregory, R. B.., J. Vac. Sci. Tech. B 21 1 (2003).
12 Saito, Y., Kawata, S., Nakane, H., Adachi, H., Appl. Surf. Sci. 146 177 (1999).
13 Kang, C.S., Cho, H.-J., Kim, Y.H., Choi, R., Onishi, K., Shahriar, A., Lee, J.C., J. Vac. Sci. Technol. B 21 5 (2003).
14 Moriwaki, M., Yamada, T., Jpn. J. Appl. Phys., 40 Part 1, 4B 2679 (2001).
15 Park, D-G., Cho, H-J., Lim, K-Y., Cha, T-H., Yeo, I-S., Park, J-W., J. Electrochem. Soc., 148 9 F189 (2001).
16 Park, D-G., Lim, K-Y., Cho, H-J., Cha, T-H., Kim, J-J., Ko, J-K., Yeo, I-S., Park, J-W., 2001 Symp. VLSI Tech. Dig., (2001).
17 Yu, H.Y., Lim, H.F., Chen, J.H., Li, M.F., Zhu, C., Tung, C.H., Du, A.Y., Wang, W.D., Chi, D.Z., Kwong, D.-L., IEEE Elec. Dev. Lett., 24 4 (2003).
18 Suh, Y-S., Heuss, G., Misra, V., J. Vac. Sci. Technol. B 22 1 (2004).
19 Park, D-G., Cha, T-H., Lim, K-Y., Cho, H-J., Kim, T-K., Jang, S-A., Suh, Y-S., Misra, V., Yeo, I-S., Roh, J-S., Park, J-W., Yoon, H-K., IEDM Tech. Dig., 2001, p. 671, (2001).
20 Wahlstrom, U., Hultman, L., Sundgren, J.-E., Adibi, F., Petrov, I., Green, J.E., Thin Solid Films, 235 6270 (1993).
21 Esaka, F., Furuya, K., Shimada, H., Imamura, M., Matsubayashi, N., Kikuchi, T., Ichimura, H., Kawana, A., Surf. Interface Analysis, 27 1098 (1999)
22 Hobbs, C., Fonseca, L., Dhandapani, V., Samavedam, S., Taylor, B., Grant, J., Dip, L., Triyoso, D., Hegde, R., Gilmer, D., Garcia, R., Roan, D., Lovejoy, L., Rai, R., Hebert, L., Tseng, H., White, B. and Tobin, P.. 2003 Symp. on VLSI Tech. Digest (2003)
23 Yeo, Y. C., Ranade, P., King, T-J., Hu, C.. IEEE Elec. Dev. Lett. 23 6 342 (2002)
24 Samavedam, S.B., La, L.B., Tobin, P.J., White, B., Hobbs, C., L.Fonseca, R.C., Demkov, A.A., Schaeffer, J., Luckowski, E., Raymond, M., Triyoso, D., Dhandapani, V., Roan, D., Garcia, R., Martinez, A., Moore, K., Tseng, H.H., Capasso, C., Adetutu, O., Gilmer, D.C., Taylor, W.J., Hegde, R., Grant, J., 2003 IEDM Tech. Dig., (2003)
25 Tersoff, J., Phys. Rev. Lett. 52, 465 (1984)
26 Spicer, W.E., Chye, P.W., Skeath, P.R., Su, C.Y., Lindau, I., J. Vac. Sci. Technol. 16, 1422 (1979)
27 Hasegawa, H., Ohno, H., J. Vac. Sci. Technol. B 4, 1130 (1986)
28 Freeouf, J.L., Woodall, J.M., Appl. Phys. Lett. 39, 727 (1981)
29 Tung, R.T., Mat. Sci. Engr. R, 35 1138 (2001).
30 Perfetti, P., Quaresima, C., Coluzz, C., Fortunate, C., Margaritondo, G., Phys. Rev. Lett., 57 16 2065 (1986).
31 Schaeffer, J., L.Fonseca, R.C., Samavedam, S.B., Liang, Y., Tobin, P.J., White, B.E., (Submitted for publication).
32 Fonseca, L.R.C., presented at the 2003 MRS Spring Meeting, Boston, MA, 2003 (unpublished).
33 Schmiedl, R., Demuth, V., Lahnor, P., Godehardt, H., Bodschwinna, Y., Harder, C., Hammer, L., Strunk, H.-P., Schulz, M., Heinz, K.., Appl. Phys. A 62, 223 (1996)
34 Fillot, F., Chenevier, B., Maitrejean, S., Audier, M., Chaudouet, P., Bochu, B., Senateur, J.P., Pisch, A., Mourier, T., Monchoix, H., Guillaumot, B., Passemard, G., Microelec. Engr. 70 384391 (2003)
35 Fillipov, V.I., Terentjev, A.A., Yakimov, S.S., Sensors and Actuators B 41, 153 (1997)
36 Flietner, B., Doll, T., Lechner, J., Leu, M., Eisele, I., Sensors and Actuators B 22, 109 (1994)
37 Robertson, J., J. Vac. Sci. Technol. B 18, 1785 (2000)
38 Fonseca, L.R.C. and Liang, Y. (private communications)
39 Baikie, I.D., Peterman, U., Lagel, B., Dirscherl, K., J. Vac. Sci. Technol. A 19 4 1460 (2001)

Investigations of Metal Gate Electrodes on HfO2 Gate Dielectrics

  • Jamie Schaeffer (a1), Sri Samavedam (a1), Leonardo Fonseca (a1), Cristiano Capasso (a1), Olubunmi Adetutu (a1), David Gilmer (a1), Chris Hobbs (a1), Eric Luckowski (a1), Rich Gregory (a1), Zhi-Xiong Jiang (a1), Yong Liang (a1), Karen Moore (a1), Darrell Roan (a1), Bich-Yen Nguyen (a1), Phil Tobin (a1) and Bruce White (a1)...

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