A 0.08 /spl mu/m/sup 2/-sized 8F/sup 2/ stack DRAM cell for multi-gigabit DRAM

Abstract

The first 8F/sup 2/ stack DRAM cell with 0.08 /spl mu/m/sup 2/ size has been successfully integrated by employing a poly plug scheme for landing plug contacts and W/poly gates and Ru MIM capacitors, of which cell working has been proven under easy function check mode. The cell transistor with W gate technology exhibits sufficient saturation current (I/sub OP/) of /spl sim/40 /spl mu/A with threshold voltage (V/sub tsat/) of 0.9 V and satisfactory ring oscillator delay characteristics of /spl sim/50 ps.