학술논문
(Invited) Band-Edge Effective Work Functions by Controlling HfO2/TiN Interfacial Composition for Gate-Last CMOS
Document Type
Article
Author
Source
ECS Transactions; April 2011, Vol. 35 Issue: 2
Subject
Language
ISSN
19385862; 19386737
Abstract
Effective work function (EWF) changes of TiN/HfO2annealed at low temperatures in different ambient environments are correlated to the atomic concentration of oxygen, nitrogen, and aluminum at the metal/dielectric interface. Low EWFs (4.0 eV) are obtained by allowing aluminum to migrate to the TiN/HfO2interface during a forming gas anneal. High EWFs (5.1 eV) are achieved with anneals that incorporate oxygen throughout the TiN with [O] = 2.8x1021cm-3near the TiN/HfO2interface. First-principles calculations indicate the exchange of O and N atoms near the TiN/HfO2interface cause the formation of dipoles that increase the EWF.