Controllability of flatband voltage in high-k gate stack structures - remarkable advantages of La/sub 2/O/sub 3/ over HfO/sub 2/

Author

Ohmori, K. ; Ahmet, P. ; Shiraishi, K. ; Yamabe, K. ; Watanabe, H. ; Akasaka, Y. ; Umezawa, N. ; Nakajima, K. ; Yoshitake, M. ; Nakayama, T. ; Chang, K.-S. ; Kakushima, K. ; Nara, Y. ; Green, M.L. ; Iwai, H. ; Yamada, K. ; Chikyow, T.

Author_Institution

Adv. Electron. Mater. Center, Nat. Inst. for Mater. Sci., Tsukuba

fYear

2006

fDate

23-26 Oct. 2006

Firstpage

376

Lastpage

379

Abstract

The authors have achieved a remarkably wide range (~1.2 V) of differences in flatband voltage (V_fb) by using a combination of metal alloy (Pt-W)/La2O3 gate stacks. The controllable range is about 3 times greater than that of Hf-based gate stacks. The wide range of V _fb can be maintained even after annealing in forming gas and oxidizing gas ambients. The authors consider that this is attributed to charge transfer at the Pt/La₂O₃ interfaces inducing increase in the effective work functions, especially at high Pt composition ratios. The authors believe that La₂O₃ is one of the most promising high-k dielectric materials for future CMOS devices in 32nm-node and beyond

Keywords

CMOS integrated circuits; charge exchange; dielectric materials; hafnium compounds; high-k dielectric thin films; lanthanum compounds; platinum alloys; tungsten alloys; work function; CMOS devices; HfO₂; La₂O₃; Pt-W; charge transfer; effective work function; flatband voltage; high-k dielectric materials; high-k dielectric thin films; Capacitors; Channel bank filters; Controllability; Dielectric films; Electrodes; Electrons; Hafnium oxide; High K dielectric materials; High-K gate dielectrics; Materials science and technology;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State and Integrated Circuit Technology, 2006. ICSICT '06. 8th International Conference on

Conference_Location

Shanghai

Print_ISBN

1-4244-0160-7

Electronic_ISBN

1-4244-0161-5

Type

conf

DOI

10.1109/ICSICT.2006.306256

Filename

4098113