Response to 'Comment on 'Assessment of field-induced quantum confinement in heterogate germanium electron-hole bilayer tunnel field-effect transistor'' [Appl. Phys. Lett. 106,026102 (2015)]

摘要

In our letter, we demonstrated that the inclusion of field-induced quantum confinement in the analysis of the Ge Electron-Hole Bilayer Tunnel Field-Effect Transistor (EHBTFET) led to the appearance of undesired lateral tunneling which degraded the so far reported outstanding switching behavior of these devices. We showed that a heterogate configuration (HG-EHBTFET) with different work-functions for the overlap and underlap sections of the top gate, φ_(tg1) and φ_(tg2), respectively (see Fig. 1(c) in Ref. 1), proved to be appealingly efficient to suppress this parasitic tunneling at V_D = 0.5 V and restore the steepness of the I_D -V_(TG) curves. The main point of the comment raised by Hsu et al. was to elucidate the potential drawbacks that the proposed work function difference might cause at low drain voltages. They showed that no deleterious effects arise in that scenario by analyzing the electron eigenenergy difference for the first subbands in the overlap and underlap regions, ΔE, for V_D ＜ 0.5 V and concluded that a heterogate configuration is also quite advisable at low V_D. Furthermore, they showed (Fig. 1(b) in Ref. 3) that there exists an optimized value of φ_(tg2) for which ΔE turns out to be approximately independent of V_D. Our response seeks to explain the interesting behavior of the ΔE(V_D) curves depicted in Fig. 1(b) of the comment by Hsu et al. for better understanding of the effect that heterogate configuration has on the performance of these devices. The results herein presented were obtained employing the simulation approach used in our original letter with the device structure considered by Hsu et al.