ti layer is typically about 5 1000 u00e5 and preferably about 10 100 u00e5 a conductive layer 158 is deposited over the liner 157 the conductive layer for example comprises al cu or w other conductive materials are also useful typically the conductive layer is deposited by conventional techniques such techniques include for example cvd pvd and i pvd other techniques for depositing the conductive layer are also useful to ensure that the conductive material fills the trench structure an overfill is typically employed referring to fig1 g the wafer surface is then planarized by cmp using for example the dielectric layer as an etch stop as a result the cmp removes excess liner and conductor materials from the surface of the dielectric layer producing a planar top surface 151 the conductor formed has its sidewalls and bottom lined with a liner referring to fig1 h an etch such as a cmp is optionally employed to further recess the conductor and liner materials below the surface 151 the recess provides a region in which a liner material is provided to encapsulate the contact typically the recess is about equal to the thickness of the liner 157 depending on the polishing efficiency the recess may include an additional depth that takes into account materials removed by the subsequent polishing step as shown in fig1 i a liner layer 159 is deposited on the surface 151 filling the recess referring to fig1 j the liner 159 is polished by cmp resulting in a conductor.