A surface preparation technique using an NH/sub 3/ anneal has been investigated to reduce interface reaction and consequently the equivalent oxide thickness (EOT) of hafnium oxide for alternative gate dielectric applications. MOSCAPs and MOSFETs were fabricated on the NH/sub 3/ nitrided substrates with HfO/sub 2/ dielectric and TaN gate electrode. Using this nitridation technique, EOT of as thin as 7.1 /spl Aring/ with 10/sup -2/ A/cm/sup 2/ at -1.5 V was obtained. Furthermore, excellent device characteristics and reasonable reliability have been achieved.
R. Choi, Kang, C. Seok, Lee, B. Hun, Onishi, K., Nieh, R., Dr. Sundararaman Gopalan, Dharmarajan, E., and Lee, J. C., “High-quality ultra-thin HfO/sub 2/ gate dielectric MOSFETs with TaN electrode and nitridation surface preparation”, in 2001 Symposium on VLSI Technology. Digest of Technical Papers (IEEE Cat. No.01 CH37184), 2001.