Improvement in Radiation Hardness of CMOS Inverters and Circuits by Adding Compensation Resistors

　　　　　The adding of a compensation resistor to the traditional CMOS inverter is proposed as an efficient way to reduce the CMOS threshold voltage shift caused by irradiation. A good agreement between the experimental and the simulated results is observed in both DC transfer characteristics and switching time performance. The compensation resistors with values ranging from 25KΩ to 65KΩ are suggested for CMOS inverters to have threshold voltage shift percentage (△Vth/Vth × 100%) smaller than 10% when they are irradiated by Co-60 with total doses ranging from 500K to 1M rads. A power-delay-voltage shift product is defined as an evaluation factor for choosing the most suitable compensation resistor in designing the radiation-hard circuits.