An electric field-assisted photochemical metal-organic deposition allowing control of oxygen content for resistive switching in directly patterned TiOx films

초록

Resistive RAM (ReRAM) is a promising candidate for next-generation non-volatile memory; it uses resistive switching behavior by electrochemical migration of oxygen vacancies inside of transition metal oxides. Controlling the oxygen content of the resistive switching material is required during the film deposition step for resistive switching to occur. This study Pledemonstrated an electric field-assisted photochemical metal-organic deposition (EFAPMOD) method for controlling the oxygen content of amorphous phase TiOx thin film, a commonly used material for ReRAM. Various voltages (0, + 10, + 15, + 20 V) were applied using a specially designed photomask coated with a transparent conductive oxide film during the photochemical reaction by UV irradiation. As a result, the oxygen content at the film top surface could be controlled according to the magnitude of applied voltage. This effect was confirmed by X-ray photoelectron spectroscopy (XPS) and I-V characteristic measurement. The applied positive voltage induced high oxygen content at the top interface of the TiOx film, and the local region possessing high oxygen content (high resistance) induced a resistive switching event. The TiOx amorphous film formed by EFAPMOD + 20 V showed stable and consistent resistive switching behavior.

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