Set-sweep programming pulse for phase-change memories

摘要

This paper presents a non-conventional program pulse approach for phase-change memories (PCMs). The cell programming curve is experimentally evaluated and discussed. The proposed set-sweep program pulse allows compensating for spreads in cell physical parameters. This ensures a better SET condition for marginal cells and adequately narrow SET distributions, which results in improved read margin. Experimental results have been collected from a 8-Mb BJT-selected PCM demonstrator. The effectiveness of the proposed program pulse has been proved by comparing cell distributions obtained on the whole array by means of a conventional SET box and a set-sweep program pulse, respectively.