Miniaturized high-frequency carrier-type thin-film magnetic field sensor with high sensitivity

This paper discusses miniaturization and the sensitivity of a high-frequency carrier-type thin-film magnetic field sensor. We examined a lift-off process as the fabrication process instead of ion-milling process to obtain an even edge and higher sensitivity when the sensor is miniaturized. Then, we used a thin conductive interlayer to control the domain structure and demonstrated high sensitivity. The sensor dimensions were miniaturized to 3 /spl mu/m wide, 1 /spl mu/m thick and 1 mm long. In this instance, an impedance change of 3 /spl Omega/ against external dc field was obtained. Moreover, a gain of 150 k/spl Omega//T was achieved.