Bilayer metal gate electrodes with tunable work function: Mechanism and proposed model

A bilayer metal structure has been demonstrated to adjust the gate work function over the Si band gap. The underlying tuning mechanism is believed to be due to metal interdiffusion based on comparison of work function behavior under different anneal conditions. In this paper, we conduct physical cha...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied physics 2010-03, Vol.107 (6)
Main Authors: Lu, Ching-Huang, Wong, Gloria M. T., Birringer, Ryan, Dauskardt, Reinhold, Deal, Michael D., Clemens, Bruce M., Nishi, Yoshio
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A bilayer metal structure has been demonstrated to adjust the gate work function over the Si band gap. The underlying tuning mechanism is believed to be due to metal interdiffusion based on comparison of work function behavior under different anneal conditions. In this paper, we conduct physical characterization on bilayer metal gates and successfully verify that the interdiffusion is the cause of the work function tuning. Furthermore, we find that metal interdiffusion significantly slows down after an initial anneal, resulting in a stable work function. A diffusion model involving the annealing out of fast diffusion paths is proposed to explain the work function results.
ISSN:0021-8979
1089-7550
DOI:10.1063/1.3326237