| abstract |
A process for forming a tungsten plug structure, in a contact hole, without recessing of the tungsten plug, or of the adhesive and barrier layers, located on the sides of the contact hole, during the tungsten plug patterning procedure, has been developed. The process features a two stage, in situ RIE procedure, in which a photoresist shape, larger in width than the diameter of the contact hole, is used as a mask to allow patterning of an aluminum based layer, of an underlying tungsten, and of the barrier and adhesive layers. The result of the two stage, in situ RIE procedure is an aluminum based interconnect structure, overlying a tungsten plug structure, with the tungsten plug structure comprised of a tungsten plug, in a contact hole, protected during the patterning procedure by the overlying aluminum based interconnect structure. |