Thermal treatment of a semiconductor wafer in the fabrication of integrated circuits including MOS transistors and ferroelectric capacitors, including those using lead-zirconium-titanate (PZT) ferroelectric material, to reduce variation in the electrical characteristics of the transistors. Thermal treatment of the wafer in a nitrogen-bearing atmosphere in which hydrogen is essentially absent is performed after formation of the transistors and capacitor. An optional thermal treatment of the wafer in a hydrogen-bearing atmosphere prior to deposition of the ferroelectric treatment may be performed.