By Topic

Manipulating interface dipoles of opposing polarity for work function engineering within a single metal gate stack

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)
Lim, A.E.-J. ; Dept. of Electr. & Comput. Eng., Nat. Univ. of Singapore, Singapore ; Jian Hou ; Dim-Lee Kwong ; Yee-Chia Yeo

We show, for the first time, a reversal in net interface dipole polarity (initially n-type) for a metal gate stack by forming p-type interface dipoles after a 950degC anneal. This was achieved in both TaN/SiO2 and TaN/high-k gate stacks whereby terbium (Tb) and aluminum (Al)-based interlayers were used to form n-type and p-type dipoles, respectively. We also demonstrate the continuous tunability of TaN gate work function (Phim) by controlling the n-type and p-type interface dipole densities within the same metal gate stack. The dominant dipole that results in the metal gate stack hinges critically on the reactions of Al and Tb with SiO2 (or underlying SiO2 for high-k stacks) for Al-O-(Si) and Tb-O-Si bond formation, respectively. The manipulation of interface dipoles with opposing polarity could enable multiple Phim to be achieved using a single metal gate and a simple integration scheme.

Published in:

Electron Devices Meeting, 2008. IEDM 2008. IEEE International

Date of Conference:

15-17 Dec. 2008