Pt/Al2O3/HfO2/Ti/TiN bi-layer RRAM device for imply–inhibit logic applications: Unveiling the resistive potential by experiment and simulation

Aluminum oxide (Al2O3)/hafnium oxide (HfO2) bi-layer resistive random access memory (RRAM) was fabricated by atomic layer deposition and sputtering method with a titanium (Ti)/titanium nitride (TiN) top electrode and a platinum (Pt) bottom electrode to achieve optimized performance. High-resolution transmission electron microscopy results clearly show the cross-sectional nanostructure of the Pt/Al2O3/HfO2/Ti/TiN RRAM devices. Examination of the X-ray photoelectron spectroscopy depth profile and X-ray diffraction peaks revealed the bonding state and presence of the proposed bi-layer structure. The device features a forming-free function with a stable resistance ratio (∼10) of ON/OFF states, low SET and RESET voltages, switching duration of up to 103 cycles, and longer data retention. The current–voltage characteristics of the proposed RRAM device implemented with the VTEAM simulation package and its performance with respect to the experimental results were studied. In addition, imply–inhibit logic gates were developed, and their performance was studied. The results show that the proposed imply–inhibit logic has significant advantages over typical CMOS logic in terms of performance, delay, and device count.