Bias temperature instability analysis on memory properties improved by hydrogen annealing treatment in Ti/HfOx/Pt capacitors

Abstract

The influence of the hydrogen annealing treatment on the reliability of Ti/HfOx /Pt capacitors is investigated by analyzing bias temperature instability (BTI). As compared to the N-2-annealed sample, in the case of hydrogen-annealed samples, both the set/reset voltages and currents are reduced from 6.5 V/-1.6 V to 3.8 V/-1.2 V and from 4 mA/170 nA to 800 mu A/30 nA at 0.1 V, respectively. Of particular interest is the dramatic reduction in the set voltage variation from 3.3 V to 1.8 V. In addition, in BTI experiments, the current shift at the high resistance state (HRS) is reduced from 1.5 mu A to 40 nA under a bias stress of -1 V/1000 s and from 40 mu A to 0.5 mu A under a temperature stress of 120 degrees C/1000 s. These results show that the hydrogen annealing treatment is very effective in improving the reliability of RRAM cells because it reduces the leakage current under bias temperature stress. (c) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim