Materials Science in Semiconductor Processing vol:9 issue:6 pages:880-884
The integration of high-kappa dielectrics in MOSFET devices is beset by many problems. In this paper a review on the impact of defects in high-kappa materials on the MOSFET electrical characteristics is presented. Beside the quality of the bulk of the dielectric itself, the interfaces between the high-kappa and the interfacial oxide layer and the gate electrode are of crucial importance. When poly-Si is used as gate electrode, the defects at the poly-Si/high-kappa interface control the band alignment as well as the gate depletion. The quality and thickness of the interfacial SiO2 controls both the carrier mobility in the channel as well as the kinetics of charging and discharging of pre-existing high-kappa defects. The quality of the interfacial layer has also important consequences for reliability specifications like negative bias instability and dielectric breakdown. (c) 2006 Elsevier Ltd. All rights reserved.