Low Voltage Switching Characteristics of 60 nm Thick SrBi_2Ta_2O_9 Thin Films Deposited by Plasma-Enhanced ALD

摘要

60 nm thick SrBi_2Ta_2O_9 (SBT) thin films were fabricated using plasma-enhanced atomic layer deposition (ALD) with an alternating supply of single cocktail source and oxygen plasma. The linear relationship between the number of cycles and film thickness and a constant deposition rate with source pulse time suggests that a self-limiting process that has distinct characteristics of ALD was achieved. The 60 nm thick SrBi_2Ta_2O_9 films that were annealed at 750 deg C completely crystallized to the layer-structured perovskite phase. The SBT capacitors showed excellent ferroelectric switching properties. Low voltage switching below 1.5 V was achieved successfully in the 60 nm SBT capacitor.