Roles of oxygen vacancy in HfO2/ultra-thin SiO2 gate stacks - Comprehensive understanding of VFB roll-off -

Author

Akiyama, K. ; Wang, W. ; Mizubayashi, W. ; Ikeda, M. ; Ota, H. ; Nabatame, T. ; Toriumi, A.

Author_Institution

MIRAI-ASET, AIST, Tsukuba

fYear

2008

fDate

17-19 June 2008

Firstpage

80

Lastpage

81

Abstract

This paper discusses a role of the oxygen vacancy in HfO₂/ultra-thin (UT) interfacial layer (IL) SiO₂ gate stacks, focusing on the V_FB roll-off. The metal/top-SiO₂/HfO₂/UT IL-SiO2/Si gate stacks have been studied. It is found for the first time that the VFB roll-off is eliminated by inserting 1~2 nm top-SiO₂ between metal gate and HfO₂. This elimination of the V_FB roll-off is explained by compensating the bottom dipoles at HfO₂/IL-SiO₂ interface with the counter dipoles at top-SiO₂/HfO₂ interface. Therefore it is concluded that the bottom dipole is assigned to the dominant origin of the V_FB roll-off.

Keywords

MIS structures; hafnium compounds; silicon compounds; vacancies (crystal); HfO₂-SiO₂; MIS structures; bottom dipole; counter dipoles; oxygen vacancy; ultra-thin gate stacks; ultra-thin interfacial layer; Annealing; Channel bank filters; Counting circuits; Electrodes; Hafnium oxide; High K dielectric materials; High-K gate dielectrics; MOSFET circuits; Scalability; Tin;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Technology, 2008 Symposium on

Conference_Location

Honolulu, HI

Print_ISBN

978-1-4244-1802-2

Electronic_ISBN

978-1-4244-1803-9

Type

conf

DOI

10.1109/VLSIT.2008.4588570

Filename

4588570