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

fYear

2005

fDate

14-16 June 2005

Firstpage

42

Lastpage

43

Abstract

Lanthanide-incorporated metal nitride (lanthanide-MN_x) 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 MN_x 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-MN_x 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-MN_x 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-MN_x; 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;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Technology, 2005. Digest of Technical Papers. 2005 Symposium on

Print_ISBN

4-900784-00-1

Type

conf

DOI

10.1109/.2005.1469204

Filename

1469204