On-chip electrostatic discharge protection for CMOS gas sensor systems-on-a-chip (SoC)

An on-chip electrostatic discharge (ESD) protection scheme is demonstrated for an emerging technology of microelectromechanical systems (MEMS)-based embedded sensor (ES) system-on-a-chip (SoC). The ESD protection scheme is implemented using ground-referenced multifinger thyristor-type devices optimized for (1) the input/output (I/O) protection, (2) the power supply clamp, and (3) the internal sensors’ electrodes during the micromachining process. The ESD structure developed demonstrates a leakage current below 10−10 A, high on-state conductance, and high level of human body model (HBM) immunity.