Effect of Temperature Induced Phase Variation in ALD TiO2 Dielectric on the Switching Behaviour of RRAM Devices

The improvement in performance of the resistive memory device with change in phase of insulating layer due to different deposition temperatures is investigated. The active switching layer TiO2 was deposited by Atomic Layer Deposition (ALD) at 150°C, 180 °C and 200°C to obtain amorphous, lower crystalline order, and higher crystalline order switching medium. All the devices have shown good switching characteristics but with varied endurance variability. The device with TiO2 deposited at 180 °C is giving better performance with current on/off ratio of 2>103, stable retention for 102 seconds and lower cycle-to-cycle variability. This work reports a technique to lower the cycle-to-cycle variation without introducing additional fabrication steps.