Process for high thermal stable contact formation in manufacturing sub-quarter-micron cmos devices

Abstract

A conducting plug/contact structure for use with integrated circuit includes a tungsten conducting plug formed in the via with a tungsten-silicon-nitride (WSi N ) region providing the interface between the tungsten conducting plug and the substrate (silicon) layer. The interface region is formed providing a nitrided surface layer over the exposed dielectric surfaces and the exposed substrate surface (i.e., exposed by a via in the dielectric layer) prior to the formation of tungsten/tungsten nitride layer filling the via. The structure is annealed forming a tungsten conducting plug with a tungsten-silicon-nitride interface between the conducting plug and the substrate. According to another embodiment, a tungsten nitride surface layer is formed over the nitrided surface layer prior to the formation of a tungsten layer to fill the via. According to another embodiment, a silicon surface layer is applied to the exposed surface of the dielectric layer and to the exposed surface of the substrate prior to formation of the nitrided surface layer. A layer of tungsten, tungsten/tungsten nitride, or tungsten nitride is formed to fill the via. After annealing, a tungsten conducting plug is formed with a tungsten-silicon-nitride interface region with the substrate.