Very fast transient time-to-breakdown measurements on ultra-thin oxide antifuse bitcells using a RF setup

Gate-oxide breakdown physics suffer from a lack of knowledge in a high voltage domain and short time-to-breakdown e.g. sub-second. This phenomenon is usually studied in device reliability in a DC domain. In this paper, an innovative measurement setup allowing time-to-breakdown measurements down to 10ns is presented. Antifuse bitcells fabricated in CMOS 40nm were characterized using a RF measurement setup. Stress voltage amplitudes of 5V, 6V and 7V were applied whereas their nominal voltage is 1.1V. As a result, time-to-breakdown distributions are plotted for the three stress voltages and exhibit a constant weibull slope thereby demonstrating the relevancy of the measurement setup in Time-Dependent Dielectric Breakdown characterization. A minimum time-to-breakdown of 10ns has been measured for a stress voltage of 7V.