A submicron, double level metal process for high density memory applications

A process is described that was developed for application to a 1-Mb SRAM product. This highly reliable, very dense interconnect process features tungsten metal-1 and spin-on-glass (SOG) etchback planarization. The tungsten metal layer provides excellent step coverage with good electromigration resistance. The tungsten patterning process results in very little etch bias and anisotropic etch profiles. Details relating to both metallization and planarization are discussed. The results of electrical characterization and reliability testing are presented.<
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