Patent ID: 8891293
Filing Date: 2014-11-18
Classification: G11C

Abstract:
1. A method for operating a memory cell comprising phase change material and programmable to a plurality of resistance states including a higher resistance state and a lower resistance state, the method comprising: applying a first bias arrangement to the memory cell to establish a target resistance state, the first bias arrangement comprising a first pulse to induce a first current through the phase change material; determining that the memory cell is not in the target resistance state after applying the first bias arrangement; in response to the determination, applying a second bias arrangement to the memory cell, the second bias arrangement comprising a second pulse to induce a second current through the phase change material, wherein the first pulse and the second pulse have the same voltage polarity across the phase change material, and the second pulse has a current magnitude greater than that of the first pulse; and after applying the second bias arrangement, applying a subsequent bias arrangement to the memory cell to establish the target resistance state.