High-temperature stable IrxSi gates with high work function on HfSiON p-MOSFETs

Abstract

A novel 1000 degrees C-stable IrxSi gate on HfSiON is shown for the first time with full process compatibility to current very-large-scale-integration fabrication lines and proper effective work function of 4.95 eV at 1.6-nm equivalent-oxide thickness. In addition, small threshold voltages and good hole mobilities are measured in IrxSi/HfSiON transistors. The 1000 degrees C thermal stability above pure metal (900 degrees C only) is due to the inserted 5-nm amorphous Si, which also gives less Fermi-level pinning by the accumulated metallic full silicidation at the interface.