Skip to main content Accessibility help

Material and Electrical Characterization of Carbon-Doped Ta2O5 Films for Embedded DRAM Applications

  • Karen Chu (a1), Byeong-Ok Cho (a1), Jane P. Chang (a1), Mike L. Steigerwald (a1), Robert M. Fleming (a1), Robert L. Opila (a1), Dave V. Lang (a1), R. Bruce Van Dover (a1) and Chris D.W. Jones (a2)...


We studied the effect of carbon incorporation on the material and electrical properties of Ta2O5 thin film. We doped the Ta2O5 films with carbon using pulsed-dc reactive and rfmagnetron sputtering of Ta2O5 performed in an Ar/O2/CO2 plasma. In thick (70 nm) films, an optimal amount (0.8 - 1.4 at.%) of carbon doping reduced the leakage current to 10−8 A/cm2 at +3 MV/cm, a four orders of magnitude reduction compared to that in a pure Ta2O5 film grown in similar conditions without CO2 in the plasma. This finding suggests that carbon doping can significantly improve the dielectric leakage property at an optimal concentration. X-ray Photoemission Spectroscopy (XPS) analysis showed the presence of carbonate in these electrically improved carbon-doped films. Analysis by high-resolution transmission electron microscopy (HRTEM) exhibited no morphological or structural changes in these carbon doped films. Carbon doping showed no improvement in the leakage current in thin (10 nm) Ta2O5 films. This phenomenon is explained by a defect compensation mechanism, in which the carbon-related defects remove carriers at low concentrations but form a hopping conduction path at high concentrations.



Hide All
1 Tang, K.S., Lau, W.S., Samudra, G.S., IEEE Circuits and Devices, May, 27-33, (1997)
2 Ishitani, A., Lesaicherre, P., Kamiyama, S., Ando, K., and Watanabe, H., IEICE Transactions of Electronics, E76–C, 11, 15641581 (1991)
3 Kotecki, D., Semiconductor International, 109–116, Nov (1996)
4 Kinley, K. A., Thin Solid Films, 290–291, 440446, (1996)
5 Chang, J. P., Steigerwald, M.L., Fleming, R.M., Opila, al., Appl. Phys. Lett. 74, 24 (1999)
6 Alers, G. B., Dover, R.B. van, Schneemeyer, L.F., Stirling, L., Sung, C.Y., Diodato, P.W., Liu, R., Wong, Y.H., R.M Fleming, Lang, D.V., Chang, J.P., Private Communication
7 Matsui, Y., Torii, K., Hirayama, M., Fujisaki, Y., Iijima, S., and Ohji, Y., IEEE Electron Device Letters 17, 431 (1996)
8 Chandeliere, C., Autran, J.L., Devine, R.A.B., Balland, B., Materials Sci. and Eng. R22, 269322 (1998)
9 Sun, S. C., Chen, T.F., IEEE Trans. Electron Devices, ED–44 1027 (1997)
10 Aoyama, T., Saida, S., Okayama, Y., Fujisaki, M., Imai, K., and Arikado, T., J. Electrochem. Soc. 143, 977 (1996)
11 Naghori, A., and Raj, R., Journal of American Ceramic Society, B78B, 6, 15851592, (1995)
12 Hutteman, R. D., Morabito, J.M., and Gerstenberg, D., IEEE Transactions on Parts, Hybrids, and Packaging PHP-11 (No. 1), 67 (1975)
13 Thomas, J. H. III, Appl. Phys. Lett., 22, 8, 406408, (1973)
14 Fleming, R. M., Lang, D.V., Jones, C.D.W., Steigerwald, M.L., Murphy, D.W., Alers, G.B., Wong, Y-H, Dover, R.B. van, Kwo, J. R., and Sergent, A.M., J. of Appl. Phys., 88, 2, 850862 (2000)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed