2.5 On-the-Fly Fast Charge Pumping

In order to avoid possible recovery effects, the on-the-fly charge pumping technique, also called on-the-fly fast interface trap (OFIT) technique was developed by Li et al. [25, 51, 24]. As illustrated in Fig. 2.10, the basic difference between OFIT and CP is that the low-level of the CP pulse is simultaneously used as a stress condition (for NBTI), while the actual CP measurement is performed by quickly switching back and forth between accumulation and stress . Consequently, as will be discussed in Chapter 5, the low-levels are different during stress and recovery/reference measurements, which is also depicted in Fig. 2.10. To decrease the recovery further, a low duty cycle is chosen.