Enhancement of the Transient Current Behavior of MIS Tunnel Diodes With Ultra-Edge-Thickened (UET) Oxide under the Consideration of Tunnel Oxide Areas

Abstract

In this research, the steady-state and transient behavior of the p-type metal-insulator-semiconductor (MIS) tunnel-diodes (TD) with ultra-edge-thickened (UET) oxide was studied, utilizing experimental results and TCAD simulations. The investigation explores how the gate voltage (VG) influences the gate current (IG). Additionally, the impact of the thin oxide area under the gate (Athin) on IG is examined. When VG < VFB, which is in forward bias, IG is directly proportional to Athin, resulting in a larger |IG| for the planar devices with only thin oxide. Conversely, for V ${}_{\text {G}} \gt $ 0 V, the UET devices exhibit a higher IG compared to the planar device due to more electrons supplied from the region outside the gate. The UET device, compared to the planar device, shows an enhancement of over one hundred times larger magnitude of transient current. Also, the UET devices featuring the larger Athin display a greater magnitude of transient current. However, the enhancement of transient current becomes saturated when the portions of thin and thick oxide are almost equal in area. The magnitudes of the transient currents of the UET devices are sampled at 60 ms after switching VG from write to 0 V. Endurance characteristic is also measured, revealing minimal changes after 1000 write and read cycles. To elucidate the mechanism behind the steady-state and transient current behavior, simulations are employed for both the steady-state and transient situations.