Optimization of Magnetotransistor Structure in CMOS Texhnology
Experimental results are presented for the comparison of a novel CMOS based magnetic sensor and a lateral magnetotransistor. Results indicating a dramatic increase in sensitivity are given and a linear response is obtained. An improvement in the device sensitivity of four times was measured and a maximum sensitivity of 200% / T was found. An explanation for the increase in sensitivity is proposed and confirmed by an analysis of both the electrical and magnetic characteristics of both devices. This explanation attributes the increase in sensitivity of the new device to the inhibition of laterally injected electrons from the emitter edges. This is achieved by the placement of p+ stripes along the emitter edges. Additional experimental results also show an increase in sensitivity was found as the emitter length of the magnetic sensor was shortened.