Abstract
In this contribution, NMOS and PMOS band edge effective work function (EWF) and correspondingly low Vt are demonstrated using standard fab materials and processes in a gate-last scheme. For NMOS, the use of an Al cladding layer results in Vt = 0.08 V consistent with NMOS EWF = 4.15 eV. Migration of the Al cladding into the TiN and a relatively low oxygen concentration near the TiN/HfO2 interface are responsible for the low EWF. For PMOS, employing a W cladding layer along with a post-TiN anneal in an oxidizing ambient results in elevated oxygen concentration near the TiN/HfO2 interface and Vt = -0.20 V consistent with a PMOS EWF = 5.05 eV. First-principles calculations indicate N atoms displaced from the TiN during the oxidizing anneal form dipoles at the TiN/HfO2 interface that play a critical role in determining the PMOS EWF. © 2010 IEEE.
Original language | English (US) |
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Title of host publication | 2010 Symposium on VLSI Technology |
Publisher | Institute of Electrical and Electronics Engineers (IEEE) |
Pages | 183-184 |
Number of pages | 2 |
ISBN (Print) | 9781424476374 |
DOIs | |
State | Published - Jun 2010 |