Fabrication of a Current-Perpendicular to Plane Magneto-resistive Device with a Dry Ice Blasting Lift-off Process

Sub-micron sized magnetic tunnel junctions were fabricated using a dry ice blasting lift-off process for the resist on the magnetic tunnel junction. The fabricated devices showed little difference in transport characteristics from devices made using a conventional chemical lift-off process in an ultrasonic bath sonicator. The distinguished feature of the new process was the achievement of a soft and pure dry ice jet from a well-cooled nozzle with a clear liquid CO2 flow in a narrow orifice. There was little contamination or damage on the surface of the sample wafer with the pure jet. The dry ice blasting effectively removed the resist for smaller pillar devices with planar sizes of ＜250 nm.