The effect of annealing on the switching characteristics of memristor devices cannot be overlooked because the thermal process can exhibit both positive and negative effects on the performance of the devices. We investigated the switching behavior of TaOx-based memristors (electrochemical metallization cell type, ECM) that were Ar-ambient annealed under two conditions, with and without the active electrode. We found a high concentration of metal species in the TaOx films, even in the device where the TaOx was annealed without the active top electrode. This indicates that the properties of the annealed films encourage the diffusion of metal species in the oxide. We suggest that the increase in non-lattice oxygen (by 4.1%, indicating a higher concentration of Vo defects) after the annealing process plays a role in this phenomenon. In addition, the concentration of metal species that exist prior to the switching activation as well as the structure of the conducting bridge determines the switching stability of the devices. The device that annealed before top electrode deposition shows the worst stability; conversely, the device that annealed after top electrode deposition has the best coefficient of variation of the LRS and HRS which is 4.69% and 78.8%, respectively. Electrical and materials analyses were conducted to understand this phenomenon. This study provides insight into the compatibility of ECM in CMOS post-processing.

A quaternary In0.04Al0.63Ga0.33N/GaN metal-insulator-semiconductor (MIS)-high electron mobility transistor (HEMT) on Si substrate using a GaN:C back-barrier (BB) layer and an AlGaN/AlN superlattice (SL) buffer layer to achieve a high breakdown voltage and a high output current density was demonstrated. Compared to the conventional device adopting AlGaN as the barrier layer, the proposed device showed a better 2DEG carrier density up to 1.9 x1013 cm-3, a higher output current density up to 1,070 mA/mm (improved by 47%), an on-resistance (Ron) as low as 7.64 Ω-mm (decreased by 26%), an off-state breakdown voltage up to 2,070 V, and an improved dynamic Ron performance (dynamic to static ratio increased to just 1.2 times at an applied drain-to-source stress voltage (VDS, stress) of 400 V). These results indicated the great potential of the InAlGaN/GaN MIS-HEMTs on Si for high-power switching applications.

Effect of metal electrodes and channel width on resistive switching and noise behaviour of ReS2 film.