A method for multilevel-read a phase change memory cell as well as the phase change memory

摘要

A method for multilevel read a phase-change memory cell, wherein the method comprises:Selecting a plurality of bit lines and of a plurality of pws-cells, which are each provided with a corresponding of the plurality of selected bit lines are connected;The application of a first bias voltage (v_Bl, V₀₀) on the selected bit line;Comparing a first sense current (i_rd00), in response to said first bias voltage (v_Bl, V₀₀) by means of the selected bit line flows, with a first reference current (i₀₀), the first reference current (i₀₀) in such a way that the first read current (i_rd00) in a first relationship with respect to the first reference current (i₀₀) when the selected pws-cell is located in a reset state, and the first read current (i_rd00) otherwise, in a second relationship with respect to the first reference current (i₀₀) is;It is possible to establish whether the selected pws-cell is located in the reset state, on the basis of the comparing the first sense current (i_rd00) with the first reference current (i₀₀);The application of a second bias voltage (v_Bl, V₀₁) on the selected bit line, based on a determination that the selected pws-cell are not in the reset state is located, wherein said second bias voltage (v_Bl, V₀₁) is greater than the first bias voltage (v_Bl, V₀₀); anddeselect each of the selected pws-cells, for which a current programming mode has been fixed.