Arsenic-Segregated Rare-Earth Silicide Junctions: Reduction of Schottky Barrier and Integration in Metallic n-MOSFETs on SOI

As an attempt to considerably reduce the equivalent contact resistivity of Schottky junctions, this letter studies the integration of rare-earth silicides, known to feature the lowest Schottky barriers (SBs) to electrons, coupled with a dopant segregation based on arsenic (As⁺) implantation. Both erbium (Er) and ytterbium (Yb) have been considered in the implant-before-silicide (IBS) and implant-to-silicide flavors. It is shown that the two schemes coupled with a limited thermal budget (500^degC) produce an SB below the target of 0.1 eV. The implementation of IBS arsenic-segregated YbSi_1.8 junctions in an n-type SB-MOSFET is demonstrated for the first time resulting in a current-drive improvement of more than one decade over the dopant-free counterpart.