Figure 2
Simulations and SEM images of MTJs with decelerated electron beam. Interaction-volume simulations to estimate the penetration depth for 15 µm × 15 µm MTJs with 30 nm CFMS as shown in Fig. 1 at decelerated electron-beam voltages (Vacc) of (a), 9 and (b), 12 kV. The red traces represent the backscattered electron’s (BSE) path. Corresponding scanning electron microscopy (SEM) images are taken by the upper electron detector (UED) with the BSE mode at Vacc = 10.5 and 11 kV. These two images are subtracted as shown in (c), for an MTJ with a large TMR ratio (83%) and (d), for an MTJ with a small TMR ratio (18%). Note the line observed in Fig. 2c is a scratch made during the device transfer into SEM.
