5531.2:
NanoHall: High-accuracy integrated magnetic sensor based on nano-meter Hall devices
Abstract
The final goal of this project is the development of highly accurate and stable integrated magnetic sensors based on the Hall effect. This could be achieved by judiciously using the emerging microelectronic technology with features in the 100 nm range.
We aim at an absolute accuracy of the magnetic sensitivity better than 0.5%, independent on temperature, packaging stress, and aging effects. We plan to achieve this by using the concept of self-calibration of the sensor. To this end, the sensor has to incorporate an integrated combination of a Hall device and of a coil supplied by a reference current. The coil must generate a magnetic induction higher than 1 mT using a current less than 1 mA. This is impossible with Hall devices and integrated coils of conventional dimensions. However, by scaling down the coil, the generated magnetic field increases. So the self-calibration becomes really practical at the scale of the order of 100 nm. Moreover, by placing a soft ferromagnetic layer over a planar coil, we can double the efficiency of the coil.
The main scientific objective of this study is to understand the Hall effect at the nano-meter scale and develop the scaling-down rules for Hall devices. We want to determine the physical limits of the miniaturization of Hall devices and perhaps find out ways to brake these limits.