Interfacial segregation of dopants in fully silicided metal-oxide- semiconductor gates

We have investigated the structure of Sb and Al implanted NiSi/SiO 2 interfaces. The addition of dopants has been previously found to alter operating thresholds of silicide-gated field effect transistors. We find that Sb is segregated to an interfacial site, and is in a metallic bonding configuration. In contrast, interfacial Al is in an oxidized state. The two additives would appear to alter the threshold voltages by distinctly different mechanisms. © 2005 American Institute of Physics.