Methods of fabricating microelectronic devices having increased impurity concentration between a metal silicide contact surface

摘要

A microelectronic device includes a first region having a first conductivity type. A second region having a second conductivity type contacts the first region at a junction therebetween. A metal silicide region contacts the second region at a contact surface apart from the junction. Impurities of the second conductivity type in the second region are concentrated between the contact surface and the junction, for example, in one or more subregions disposed between the contact surface and the junction. The subregions may include a first subregion adjacent the junction formed by an ion implantation at a first energy level, and a second subregion disposed between the first subregion and the contact surface formed by a second ion implantation at a different energy level. Related fabrication methods are also provided.