Patent ID: 7719069

Claim:
A three terminal magnetic sensor for use in a magnetic storage device and carried on a slider body, the slider body being made of a semiconductor material and comprising a wafer-bonded structure having a first slider body portion that is wafer-bonded together with a second slider body portion, the three terminal magnetic sensor comprising: a base region; an emitter region; a collector region comprising a top portion of the semiconductor material from the slider body; the base region comprising magnetic materials and being formed in between the emitter and the collector region; a first barrier region formed between the base region and the emitter region; a second barrier region formed between the base region and the collector region; the emitter region being adapted to receive electrons which travel perpendicular to the planes of the base, the emitter, and the collector regions; the slider body having dimensions of less than 1 mm 3 and a fly height of no greater than 3 nanometers with respect to a magnetic media; the three terminal magnetic sensor adapted to receive magnetic signals from the magnetic media at operating frequencies of 1 Gigahertz or greater; an insulator layer formed between the top portion of the semiconductor material and a remaining portion of the slider body which carries the three terminal magnetic sensor, for electrically isolating the collector region from the remaining portion of the slider body so as to effectively eliminate a capacitance otherwise present between the collector region and the magnetic media for the operating frequencies of the magnetic signals; and the insulator layer being an oxidized surface of the first slider body portion that is wafer-bonded together with the second slider body portion, where the oxidized surface faces the second slider body portion.