Origin of the flat-band voltage (Vfb) roll-off phenomenon in metal/high-k gate stacks

Author

Bersuker, G. ; Park, C.S. ; Wen, H.-C. ; Choi, K. ; Sharia, O. ; Demkov, A.

Author_Institution

SEMATECH, Austin, TX

fYear

2008

fDate

15-19 Sept. 2008

Firstpage

134

Lastpage

137

Abstract

Effect of the flat band voltage reduction (roll-off) in highly scaled high-k/metal gate stacks is discussed. The proposed mechanism explains the roll-off phenomenon as caused by the metal electrode/high-k dielectric-induced generation of positively charged oxygen vacancies in the interfacial SiO₂ layer in the high-k dielectric stack. The model is consistent with the observed roll-off dependency on the electrode and substrate type, high-k dielectric composition and thickness, temperature, etc., and its predictions were experimentally verified.

Keywords

CMOS integrated circuits; MOS capacitors; electrodes; elemental semiconductors; hafnium compounds; high-k dielectric thin films; insulated gate field effect transistors; semiconductor device models; semiconductor-insulator boundaries; silicon; silicon compounds; vacancies (crystal); CMOS technology; Si-SiO₂-HfO₂; electrode; flat band voltage reduction; flat-band voltage roll-off; high-k dielectric composition; high-k dielectric thickness; highly scaled high-k/metal gate stacks; positively charged oxygen vacancies; CMOS technology; Capacitors; Channel bank filters; Dielectric substrates; Electrodes; High K dielectric materials; High-K gate dielectrics; Temperature dependence; Testing; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Device Research Conference, 2008. ESSDERC 2008. 38th European

Conference_Location

Edinburgh

ISSN

1930-8876

Print_ISBN

978-1-4244-2363-7

Electronic_ISBN

1930-8876

Type

conf

DOI

10.1109/ESSDERC.2008.4681717

Filename

4681717