Temperature Dependence of Bias Temperature Instability (BTI) in Long-term Measurement by BTI-sensitive and -insensitive Ring Oscillators Removing Environmental Fluctuation

Measuring bias temperature instability (BTI) on ring oscillators (ROs) is frequently used. However, performance of a semiconductor chip is fluctuated dynamically due to bias, temperature and etc. BTI-sensitive and -insensitive ROs are implemented in order to extract BTI-induced degradation without those temporal fluctuation factors. A test chip including those ROs was fabricated in a 65 nm process and residual components without fluctuation could be extracted. The well-known power-law model of BTI with time exponent n = 1/6 is extracted from smooth degradation curves.