Giant Magnetoresistance (GMR) sensors for 0.35µm CMOS technology sub-mA current sensing

This paper reports on the design and fabrication of microelectronic structures for non-invasive indirect electric current sensing at the IC level. A 0.35 µm CMOS ASIC has been specifically developed for this purpose. Then, a low temperature post-process, fully compatible with the CMOS technology, has been applied for depositing Giant Magnetoresistive (GMR) sensors. Preliminary experimental results for obtaining the sensitivity of the devices are presented. The detection limit is estimated to be about 5 µA.