Method for improving the stability, write-ability and manufacturability of magneto-resistive random access memory

Abstract

This invention provides the method to overcome 4 backwards which limit the manufacturability or production yield rate of Magneto-resistive random access memory (MRAM). The key points of this invention are: (1) providing method to improve the manufacturability through reducing bias variation, by using a compensation module to correct the bias point of extreme cells; (2) providing method to improve the manufacturability through removing outlier cells (called bad cells), by using 'writing jump-over' and 'reading exclusion' to exclude bad-cells; (3) providing method to reduce the bias point, amplitude and asymmetry variation, using shared fixed-magnetic-reference-layer and proper shape anisotropy; (4) providing method to improve the write-ability, using flipping-assistant-field to speed up STT flipping process by large current, and using heating resistance and heating cells by the same current (including global heating, row heating, column heating, or local cell heating, i.e. heating with conventional thermal nature or heating with thermagnonic spin-transfer torque).