Non-volatile memory (NVM) will play a very important role in the next-generation digital technologies, including the Internet of things. The metal-oxide memristors, especially based on HfO2, have been favored by lots of researchers because of its simple structure, high integration, fast operation speed, low power consumption, and high compatibility with advanced (complementary metal oxide silicon) CMOS technologies. In this paper, a 20-level stable resistance states Al-doped HfO2-based memristor is presented. Its cycles endurance, data retention time, and resistance ratio are larger than 103, > 104 s, and > 10, respectively.

La2O3 films were grown on Si substrates by atomic layer deposition technique with different thickness. Crystallization characteristics of the La2O3 films were analyzed by grazing incidence X-ray diffraction after post-deposition rapid thermal annealing treatments at several annealing temperatures. It was found that the crystallization behaviors of the La2O3 films are affected by the film thickness and annealing temperatures as a relationship with the diffusion of Si substrate. Compared with the amorphous La2O3 films, the crystallized films were observed to be more unstable due to the hygroscopicity of La2O3. Besides, the impacts of crystallization characteristics on the bandgap and refractive index of the La2O3 films were also investigated by X-ray photoelectron spectroscopy and spectroscopic ellipsometry, respectively.

In this paper, the effects of Cu insertion layer and rapid thermal annealing on the resistive switching behaviors of La-based resistive switching access memory (RRAM) devices have been investigated. Compared with the undoped control sample (Cu/LaAlO3/Pt), the Cu-embedded devices show higher device yield and reset stop voltage, which indicates that the reliability of La-based RRAM has been effectively improved. However, the unannealed Cu/LaAlO3: Cu/Pt RRAM device still suffers from serious dispersion of parameters. It was proved that the RRAM device with Cu insertion layer and annealing treatment exhibits the best resistive switching characteristics such as low forming voltage, high on/off ratio and fine electrical uniformity. These improvements can be attributed to the diffusion of Cu atoms and the formation of Cu nanocrystals (Cu-NCs) after annealing process, since the diffused Cu atoms and the Cu-NCs could enhance the local electric field and weaken the randomness of the formation/rupture of conductive filaments.

The influence of processing parameters of aluminum oxide (Al₂O₃) and lanthanum oxide (La₂O₃) gate dielectric is investigated. Trimethylaluminum (TMA) and tris(isopropylcyclopentadienyl) lanthanum [La(iPrCp)₃] were used as precursors separately, and H₂O was used as oxidant. The ultra-thin La_{1 − x} Al _x O₃ gate dielectric films are deposited on p-type silicon substrates by atom layer deposition (ALD) for different pulse ratios of precursors. Effects of different La/Al precursor pulse ratios on the physical properties and electrical characteristics of La_{1 − x} Al _x O₃ films are studied. The preliminary testing results indicate that the increase of La precursor pulse can improve the characteristics of film, which has significant effects on the dielectric constant, equivalent oxide thickness (EOT), electrical properties, and stability of film.

In this study, the physical and electrical characteristics of Al₂O₃/La₂O₃/Al₂O₃/Si stack structures affected by the thickness of an Al₂O₃barrier layer between Si substrate and La₂O₃layer are investigated after a rapid thermal annealing (RTA) treatment. Time of flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) tests indicate that an Al₂O₃barrier layer (15 atomic layer deposition (ALD) cycles, approximately 1.5 nm) plays an important role in suppressing the diffusion of silicon atoms from Si substrate into the La₂O₃layer during the annealing process. As a result, some properties of La₂O₃dielectric degenerated by the diffusion of Si atoms are improved. Electrical measurements (C-V,J-V) show that the thickness of Al₂O₃barrier layer can affect the shift of flat band voltage (V_FB) and the magnitude of gate leakage current density.