A new approach to evaluation of hot-carrier lifetime of ring oscillator (RO)

The paper presents a novel experimental method to evaluate AC hot-carrier lifetime of a ring oscillator (RO). By using a series of different stages of ring oscillators (DSROs), the new method allows one to maintain a constant frequency (f/sub 0/) and obtain a closer value between pulse-to-pulse voltage (V/sub p-p/) and bias condition throughout the RO lifetime testing. These two achievements eliminate the innate flaws in conventional RO hot-carrier test method. Hence, a more reliable AC lifetime of RO is expected.