Forming-Free, Fast, Uniform, and High Endurance Resistive Switching From Cryogenic to High Temperatures in W/AlOx/Al2O3/Pt Bilayer Memristor

Through oxygen profile engineering, we fabricated W/AlO _x /Al ₂ O ₃ /Pt bilayer memristors with a 250-nm feature size. The AlOX fabricated by sputtering serves as an oxygen vacancy source, whereas the Al ₂ O ₃ deposited by atomic layer deposition acts as a dominant resistive switching (RS) layer. Our devices show forming-free RS behaviors with high speed (28 ns), uniform resistance distribution, large on/off ratio (~10 ³ @100K, ~10 ³ @298K, and ~80@400K), and good retention. Besides, temperature stability with record high endurance from cryogenic to high-temperature (10 ⁸ @100K, 10 ¹⁰ @298K, and 10 ⁷ @400K) is demonstrated, to the best of our knowledge.