Process for making contact plug

摘要

A process for fabricating contact plugs for semiconductor IC devices. An insulating layer is formed over the surface of an IC substrate. The insulating layer is then patterned for forming contact vias revealing the surface of an electrically conductive region of the IC circuitry that requires electrical connections by the contact plugs. A glue (adhesive) layer is then formed over the sidewall surface inside the contact vias. The glue (adhesive) layer is densified by either a rapid thermal annealing or a plasma treatment in order to prevent the formation of voids when the plugs are formed. The internal space of the contact vias are then filled with an electrically conductive material to form the contact plugs. The surface of the device substrate is then polished to remove the electrically conductive material and glue layer covering the surface of the insulating layer until the insulating layer surface is exposed, and top surface of the formed contact plug is planarized flat with the surface of the insulating layer.