Title :
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
Abstract :
The authors have achieved a remarkably wide range (~1.2 V) of differences in flatband voltage (Vfb) 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;
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
DOI :
10.1109/ICSICT.2006.306256
