Extremely Low Voltage Operatable On-Chip- Monitor-Test Circuit for Plasma Induced Damage using High sensitivity Ring-VCO(Voltage Controlled Oscillator)

We developed an on-chip-monitor-test circuit that measures Vth fluctuation caused by plasma induced damage (PID) during wafer process with using a novel ring voltage controlled oscillator (Ring- VCO) at low Vdd operation condition. The circuit can be easily implemented to conventional design and applied to product test. We have demonstrated that the circuit fabricated by 28nm process can monitor Vth fluctuation due to PID with operating voltage at 0.5V, which can be used for low power IoT products by 28nm CMOS technology and beyond.