Hn. Al-shareef et al., Device performance of in situ steam generated gate dielectric nitrided by remote plasma nitridation, APPL PHYS L, 78(24), 2001, pp. 3875-3877
In situ steam generated (ISSG) oxides have recently attracted interest for
use as gate dielectrics because of their demonstrated reliability improveme
nt over oxides formed by dry oxidation. [G. Minor, G. Xing, H. S. Joo, E. S
anchez, Y. Yokota, C. Chen, D. Lopes, and A. Balakrishna, Electrochem. Sec.
Symp. Proc. 99-10, 3 (1999); T. Y. Luo, H. N. Al-Shareef, G. A. Brown, M.
Laughery, V. Watt, A. Karamcheti, M. D. jackson, and H. R. Huff, Proc. SPIE
4181, 220 (2000).] We show in this letter that nitridation of ISSG oxide u
sing a remote plasma decreases the gate leakage current of ISSG oxide by an
order of magnitude without significantly degrading transistor performance.
In particular, it is shown that the peak normalized transconductance of n-
channel devices with an ISSG oxide gate dielectric decreases by only 4% and
the normalized drive current by only 3% after remote plasma nitridation (R
PN). In addition, it is shown that the reliability of the ISSG oxide exhibi
ts only a small degradation after RPN. These observations suggest that the
ISSG/RPN process holds promise for gate dielectric applications. (C) 2001 A
merican Institute of Physics.