Method for forming a capacitor using tantalum nitride as a capacitor dielectric

摘要

A method for fabricating capacitors for semiconductor devices utilizing a Ta3N5 dielectric layer is provided by the present invention. This method includes the steps of forming a lower electrode on a semiconductor substrate, depositing an amorphous TaON thin film over the lower electrode, and subjecting the deposited amorphous TaON thin film to a thermal process in an NH3 atmosphere, thereby forming a Ta3N5 dielectric film, and forming an upper electrode on the Ta3N5 dielectric film. The resulting Ta3N5 dielectric film provides a dielectric constant significantly greater than those that can be achieved with conventional dielectric films. Accordingly, the Ta3N5 dielectric film of the present invention can be used to manufacture capacitors for the next generation semiconductor memory devices of 256M grade or higher.