The Copper Contamination Effect of Al2 O 3 Gate Dielectric on Si

Abstract

We have studied the Cu contamination effect on 4.2 nm thick metal-oxide semiconductor (MOS) capacitors with an equivalent-oxide thickness (EOT) of 1.9 nm. In contrast to the large degradation of gate oxide integrity of control 3.0 nm MOS capacitors contaminated by Cu, the 1.9 nm EOT MOS devices have good Cu contamination resistance with only small degradation of gate dielectric leakage current, charge-to-breakdown, and stress-induced leakage current. This strong Cu contamination resistance is similar to oxynitride (with high nitrogen content), but the gate dielectric has the advantage of higher κ value and lower gate dielectric leakage current. © 2004 The Electrochemical Society. All rights reserved.