Test Methods for TID Effects on Capacitors

This work presents an on-chip capacitance measurement methodology for a metal-oxide-metal (MOM) capacitor based on ring oscillator measurements. This time-domain measurement technique showcases a 7% error in measurement of the capacitance of 2fF over a range of 4GHz. This is further used to evaluate potential frequency changes of both the underlying ring oscillator and metal-oxide-metal capacitance under total ionizing dose. A high sensitivity in the measurement makes it well suited for in-situ measurements useful in radiation characterization.