Fig. 2: Performances of the GIM 2D FGMs.
a Schematic diagram of the multi-gate configurated GIM 2D FGM and the equivalent circuit when VDS and Vprog are applied to the corresponding terminals. The capacitor value (Ci) between a specific gate and the FG is strongly correlated with the gate area. b OM image of the multi-gate device. The channel MoS2 thickness was determined to be about 2.6 nm by atomic force microscope (see Supplementary Fig. 23), equivalent to four layers of MoS274. The white-dashed and red-dashed areas denote the floating gate and channel/gate overlapping regions, respectively. The channel’s width/length is 10.37/1.47 μm (see Supplementary Fig. 16 for detailed geometric parameters). Scale bar: 5 μm. c Dual-sweep transfer curves of selected three gates G1, G2, and G3, which are corresponding to areas A1, A2, and A3 in (b). d Memory window as a function of the area ratio Ai/A0 with a linear fitting curve. Inset: the linear scale plot. e Vprog during carrier erasing/injection operation as a function of area ratio. The erasing and injection operations were conducted to alternatively change IDS between ~1 uA and ~1 pA. f Retention of 4 exponentially separated states for 10,000 s. The states were read by a source-drain voltage of Vread = 0.1 V. g Endurance performance during 105 program/erase cycles. 5-us-width programming pulse and tuning pulse were applied with a gap of 200 μs in a single programming/erasing operation. Cycle period: 100 ms. The programming schematic is shown as the inset. Vtune = 2 V.
