Highly reliable MIM capacitor technology using low pressure CVD-WN cylinder storage-node for 0.12 /spl mu/m-scale embedded DRAM

Abstract

A metal-insulator-metal (MIM) capacitor process technology has been developed using highly reliable ultra-thin Ta/sub 2/O/sub 5/ capacitors with low pressure CVD-WN cylinder storage-nodes for 0.12 /spl mu/m-scale embedded DRAMs. The CVD-WN films using WF/sub 6/ and NF/sub 3/ gases have excellent characteristics with respect to surface morphology and step coverage in comparison with CVD-W films. As a result, the cell capacitance with CVD-WN cylinder storage-nodes is increased to 1.5 times as large as that of CVD-W cylinder storage-nodes. The CVD-WN cylinder capacitors can realize a 30 fF/cell capacitance with 0.6 /spl mu/m-height storage-nodes in an area of 0.25/spl times/0.5 /spl mu/m/sup 2/.