Thermal treatment for reducing transistor performance variation in ferroelectric memories

摘要

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.

主权项

1. A method of fabricating an integrated circuit, comprising the steps of:
forming at least one metal-oxide-semiconductor (MOS) transistor near a semiconducting surface of a body; then forming at least one ferroelectric capacitor near the surface of the body; forming an interlevel dielectric layer and a conductor level above the at least one ferroelectric capacitor; then thermally treating the body in a non-hydrogen-bearing atmosphere that includes a nitrogen-bearing gas; and then depositing a protective overcoat layer; wherein no thermal treatment is performed after the step of depositing the protective overcoat layer.