A high output mode for submicron M-R memory cells

Abstract

A mode which substantially increases the nondestructive read output from submicron magnetoresistive (MR) memory elements has been demonstrated. This mode increases the output for large cells by 50% and the outputs of cells less than a micron wide by 150% to 300%. In this mode, information is stored in the direction of the edge magnetization, and the body of the element serves as a sensor. Outputs of +or-1.2 mV were obtained with cells with an active area of 0.7*3.0 microns. By appropriate use of a step in the field oxide and a word line keeper, the demagnetizing field in the long dimensions of a memory element can be tailored to one desired value to optimize the response characteristics. The mode requires an additional drive strap to write the edge magnetization by coincident selection. For memory application the threshold for switching the edge magnetization must be tightly controlled. >