Monolithic integration of Giant Magnetoresistance (GMR) devices onto standard processed CMOS dies

• Deposition of GMR devices on non-dedicated CMOS dies is demonstrated and evaluated.
• A 2D-FEM model including dependence of resistance with magnetic field is developed.
• The capability of measuring integrated electric circuit currents is demonstrated.
• The signal-to-noise ratio (SNR) of the obtained devices is analyzed.

Giant Magnetoresistance (GMR) based technology is nowadays the preferred option for low magnetic fields sensing in disciplines such as biotechnology or microelectronics. Their compatibility with standard CMOS processes is currently investigated as a key point for the development of novel applications, requiring compact electronic readout. In this paper, such compatibility has been experimentally studied with two particular non-dedicated CMOS standards: 0.35 μm from AMS (Austria MicroSystems) and 2.5 μm from CNM (Centre Nacional de Microelectrònica, Barcelona) as representative examples. GMR test devices have been designed and fabricated onto processed chips from both technologies. In order to evaluate so obtained devices, an extended characterization has been carried out including DC magnetic measurements and noise analysis. Moreover, a 2D-FEM (Finite Element Method) model, including the dependence of the GMR device resistance with the magnetic field, has been also developed and simulated. Its potential use as electric current sensors at the integrated circuit level has also been demonstrated.

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