Advantage of La2O3 gate dielectric over HfO2 for direct contact and mobility improvment

Author

Kakushima, K. ; Tachi, K. ; Adachi, M. ; Okamoto, K. ; Sato, S. ; Song, J. ; Kawanago, T. ; Ahmet, P. ; Tsutsui, K. ; Sugii, N. ; Hattori, T. ; Iwai, H.

Author_Institution

Interdiscipl. Grad. Sch. of Sci. & Eng., Tokyo Inst. of Technol., Tokyo

fYear

2008

fDate

15-19 Sept. 2008

Firstpage

126

Lastpage

129

Abstract

Advantage of La₂O₃ over HfO₂ MOSFET has been experimentally examined. Silicate reaction especially observed at La₂O₃/Si interface has been found to suppress the formation of SiO₂ layer to realize direct contact, which is useful for further scaling in equivalent oxide thickness (EOT). Due to the lack of interfacial layer, La₂O₃ has showed relatively high interfacial state density, however, the effective mobility has exceeded to that of HfO₂ MOSFET. Mobility analysis has revealed an additional Coulomb scattering at small EOT, suggesting the influence of metal gate. A simple mobility degradation model is pointed out using metal induced defects.

Keywords

MOSFET; electronic density of states; hafnium compounds; interface states; lanthanum compounds; Coulomb scattering; La₂O₃-HfO₂; MOSFET; equivalent oxide thickness; gate dielectric; interfacial state density; metal induced defects; mobility analysis; Annealing; Degradation; Fabrication; Hafnium oxide; High K dielectric materials; High-K gate dielectrics; MOSFET circuits; Semiconductor device modeling; Sputtering; Temperature;

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.2008.4681715

Filename

4681715