High performance of novel oxygen diffusion barrier materials for future high-density dynamic random access memory devices

Abstract

A new design concept for diffusion barriers in highdensity memory capacitors was suggested, and both the RuTiN and the RuTiO films, as sacrificial oxygen diffusion barriers, were proposed. Contact resistance, the most important electrical parameter for the diffusion barrier in the bottom electrode structure of capacitors, exhibited as low as 5 kΩ even after annealing up to 750 °C. The capacitance behavior of the simple stack-type structure adopted TiNbarrier layer initially degraded after annealing at 500 °C, and thereafter, completely failed. In the case of the RuTiN barrier layer, however, the capacitance was shown to be more than 28 fF/cell up to 600 °C. Correspondingly, the RuTiN film, as a sacrificial oxygen diffusion barrier for high-density capacitors, exhibited much higher diffusion barrier performance than the TiN barrier layer.