Laser-modulated formation of conduction path for the achievement of ultra-low switching voltage in resistive random-access memory (RRAM)

Energy saving is one of critical issues that must be seriously considered for the development of next-generation memory devices. In this study, an ultralow-power resistive random-access memory (RRAM) device is fabricated through use of a successful modulation of the AlOX layer by a laser treatment optimized for the energy saving in resistive switching (RS). The device shows not only multilevel memory properties but also a high on/off ratio (∼106), good endurance (300 cycles), and excellent retention (>104 s). Most importantly, the laser-modulated device achieves ultra-low set and reset voltages (0.06 V and −0.04 V), leading to a very low-power consumption. It was observed that the amorphous phase in the AlOX layer is transformed into the polycrystalline phase and a concentration gradient of oxygen vacancies is secured. The grain boundaries in the polycrystalline act as pathways to facilitate the movement of oxygen vacancies. Meanwhile, the concentration gradient accelerates the diffusion mobility of the oxygen vacancies. The highly potential application of the laser-modulation to the flexible RRAM devices has been demonstrated by a strong level of RS performance maintenance from a device fabricated using the polyethylene terephthalate (PET) substrate. [Display omitted] •Laser modulation transforms the phase of the AlOX from amorphous to polycrystalline.•Laser modulation provides a concentration gradient of oxygen vacancy in the AlOX.•Laser-modulated device achieved the ultra-low switching voltages.•Laser modulation method is suitable for flexible application of the RRAM device.