Systems and methods for controlling soft bias thickness for tunnel magnetoresistance readers

摘要

Systems and methods for controlling a thickness of a soft bias layer in a tunnel magnetoresistance (TMR) reader are provided. One such method involves providing a magnetoresistive sensor stack including a free layer and a bottom shield layer, performing contiguous junction milling on the sensor stack, depositing an insulating layer on the sensor stack, depositing a spacer layer on the insulating layer, performing an angled milling sub-process to remove preselected portions of the spacer layer, depositing a soft bias layer on the sensor stack, and depositing a top shield layer on the sensor stack and the soft bias layer. The method can further involve adjusting an alignment of a top surface of the spacer layer with respect to the free layer. In one such case, the top surface of the spacer layer is adjusted to be below the free layer.