Title :
Lanthanide-incorporated metal nitrides with tunable work function and good thermal stability for NMOS devices
Author :
Ren, C. ; Chan, D.S.H. ; Faizhal, B.B. ; Li, M.-F. ; Yeo, Y.C. ; Trigg, A.D. ; Agarwal, A. ; Balasubramanian, N. ; Pan, J.S. ; Lim, P.C. ; Kwong, D.L.
Author_Institution :
Dept. of Electr. & Comput. Eng., National Univ. of Singapore, Singapore
Abstract :
Lanthanide-incorporated metal nitride (lanthanide-MNx) is investigated as a novel n-type metal gate electrode with tunable work function and good thermal stability for the first time. By incorporating lanthanide elements, such as terbium (Tb), erbium (Er), or ytterbium (Yb), into metal nitride gates, such as TaN and HfN, the work function of MNx can be continuously tuned down to 4.2∼4.3 eV even after 1000°C RTA by varying the lanthanide concentrations. In addition, the lanthanide-MNx gates exhibit good thermal stability up to 1000°C on both SiO2 and high-k HfAlO. Possible mechanism for the stability of these metal gates is also discussed and the results show that the enhancement of the nitrogen content in lanthanide-MNx films could be responsible.
Keywords :
CMOS integrated circuits; MIS devices; aluminium compounds; dielectric thin films; erbium; hafnium compounds; metal-semiconductor-metal structures; nanopatterning; rapid thermal annealing; silicon compounds; sputter deposition; terbium; thermal stability; ytterbium; HfAlO; NMOS device; SiO2; erbium; lanthanide concentrations; lanthanide elements; lanthanide-MNx; lanthanide-incorporated metal nitride; metal nitride gates; n-type metal gate electrode; nitrogen content; terbium; thermal stability; tunable work function; ytterbium; Argon; CMOS process; Dielectric materials; Electrodes; Erbium; MOS devices; Microelectronics; Nitrogen; Thermal stability; Ytterbium;
Conference_Titel :
VLSI Technology, 2005. Digest of Technical Papers. 2005 Symposium on
Print_ISBN :
4-900784-00-1
DOI :
10.1109/.2005.1469204
