VOLTAGE-CYCLING RECOVERY OF PROCESS-DAMAGED FERROELECTRIC FILMS

摘要

An integrated circuit is formed containing a metal-oxide ferroelectric thin film (122). An voltage-cycling recovery process is conducted to reverse the degradation of ferroelectric properties caused by hydrogen. The voltage-cycling recovery process is conducted by applying 10 4 to 10 11 voltage cycles with an amplitudefrom 1 to 15 volts. Conducting voltage-cycling at a higher temperature in the range 30-200 DEG C enhances recovery. The metal oxide t hin film (122) comprise perovskite material like lead zirconium titanate (PZT) or layered super lattice material, preferably strontium bismuth tantalate (SBT) or strontium bismuth tantalum niobate (SBTN). If the integrated circuit manufacture includes a forming-gas anneal, then the voltage-cycling recovery process is performed after the forming-gas anneal. The voltage-cycling recovery process obviates oxygen-recovery annealing, and it allows continued use of conventional hydrogen-rich plasma processes and forming-gas anneals without the risk of permanent damage to the ferroelectric thin film(122).