Multilevel resistive switching in ternary HfxAl1-xOy oxide with graded Al depth profile

HfxAl1-xOy films with graded Al depth profile were grown by atomic layer deposition.The graded HfxAl1-xOy based stacks exhibit multilevel resistive switching behavior.Resistive switching is described in terms of redistribution of the oxygen vacancies. In this work, HfxAl1-xOy films with graded Al depth profile are grown by atomic layer deposition (ALD). HfxAl1-xOy based Pt/HfxAl1-xO/TiN stacks exhibit multilevel resistive switching behavior as revealed by I-V measurements. The distribution of the charged oxygen vacancies across as grown graded HfxAl1-xOy layer on Pt underlayer is evident from the X-ray photoemission spectroscopy analysis. The resistance switching in the graded HfxAl1-xOy layer is described in terms of the redistribution of the charged oxygen vacancies following the external biasing of the opposite polarities.