Widely Tunable Work Function TaN/Ru Stacking Layer on HfLaO Gate Dielectric

Author

Wang, X.P. ; Li, M.-F. ; Yu, H.Y. ; Yang, J.J. ; Chen, J.D. ; Zhu, C.X. ; Du, A.Y. ; Loh, W.-Y. ; Biesemans, S. ; Chin, Albert ; Lo, G.Q. ; Kwong, D.L.

Author_Institution

Nat. Univ. of Singapore, Singapore

Volume

29

Issue

1

fYear

2008

Firstpage

50

Lastpage

53

Abstract

For the first time, we demonstrate experimentally that using HfLaO high-kappa gate dielectric and vertical stacks of TaN/Ru metal layers, dual metal gates with continuously tunable work function over a very wide range from 3.9 to 5.2 eV, can be achieved after 1000 degC annealing required by a conventional CMOS source/drain activation process. The wide tunability of work function for this bilayer metal structure is attributed to metal interdiffusion during annealing and the release of Fermi level pinning between metal gates (Ru and TaN) and HfLaO. Moreover, this change is thermally stable and unaffected by a subsequent high temperature process.

Keywords

CMOS logic circuits; annealing; circuit tuning; hafnium compounds; CMOS source/drain activation process; annealing; hafnium compounds; stacking; Annealing; CMOS technology; Dielectrics; Etching; Hafnium compounds; Laboratories; MOSFET circuits; Microelectronics; Silicon; Stacking; CMOS; Fermi level pinning; HfLaO; high- $kappa$ dielectric; interdiffusion; metal gate; work function;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2007.911608

Filename

4408759