Bi-modal halo implantation

摘要

Methods of fabricating halo regions are provided. In one aspect, a method is provided of fabricating a first halo region and a second halo region for a circuit device of a first conductivity type and having a gate structure with first and second sidewalls. The first halo region of a second conductivity type is formed by implanting the substrate with impurities in a first direction toward the first sidewall of the gate structure. The second halo region of the second conductivity type is formed by implanting the substrate with impurities in a second direction toward the second sidewall of the gate structure. The first and second halo regions are formed without implanting impurities in a direction substantially perpendicular to the first and second directions.