A stacked capacitor with an MOCVD-(Ba,Sr)TiO/sub 3/ film and a RuO/sub 2//Ru storage node on a TiN-capped plug for 4 Gbit DRAMs and beyond

Abstract

A stacked high-/spl epsiv//sub r/ capacitor is fabricated using a 550/spl deg/C-process-tolerant RuO/sub 2//Ru storage node on a TiN-capped plug and an ECR plasma MOCVD (Ba,Sr)TiO/sub 3/ (BST) thin film with small SiO/sub 2/ equivalent thickness (t/sub eq/) of 0.40 nm. The contact resistance (Rc) of a 0.15 /spl mu/m diameter (/spl phi/) contact is as low as 50 k/spl Omega/. With this capacitor technology, a cell capacitance (Cs) of 25 fF is achieved in projected areas of 0.055 /spl mu/m/sup 2/ for 4 Gbit DRAMs and 0.031 /spl mu/m/sup 2/ for 16 Gbit DRAMs with 0.25 /spl mu/m- and 0.37 /spl mu/m-high storage nodes.