can serve as a barrier to prevent conductive material from diffusing there through the barrier layer may have a thickness from approximately 4 nm to approximately 40 nm more typically approximately 7 nm to approximately 20 nm conductive feature 104 includes for example polysilicon a conductive metal e g cu w an alloy comprising at least one conductive metal e g al with cu or a cu alloy a conductive metal silicide or combinations thereof conductive feature 104 has an upper surface 105 that is substantially coplanar with an upper surface 103 of the first dielectric material 102 on which dielectric capping layer 106 is disposed dielectric capping layer 106 includes any suitable dielectric capping material like silicon carbide sic tetrasilicon ammonia si 4 nh 3 silicon oxide sio 2 a carbon doped oxide a nitrogen and hydrogen doped silicon carbide sic n h or multiple layers thereof a thickness of the dielectric capping layer 106 may range for example from approximately 15 nm to approximately 55 nm however a thickness from approximately 25 nm to approximately 45 nm may be used second dielectric material 108 which may be the same as that of first dielectric material 102 is disposed on dielectric capping layer 106 portions of dielectric capping layer 106 are etched to expose conductive feature 104 in the process of forming line opening 200 a to allow electrical contact between lower interconnect.