Patent ID: 7800153

Claim:
A semiconductor device having a memory cell, the memory cell comprising: a memory cell selecting MISFET, which comprises a gate insulating film formed on a semiconductor substrate, a gate electrode formed on the gate insulating film, and a pair of semiconductor regions formed in the semiconductor substrate at both sides of the gate electrode; and a data-storing capacitor element, which comprises a first electrode electrically connected to one of the pair of semiconductor regions, a capacitor dielectric film formed on the first electrode and a second electrode formed on the capacitor dielectric film; wherein the capacitor dielectric film comprises a first layer comprised of niobium oxide and a second layer comprised of tantalum oxide, wherein the second layer is formed on the first layer such that the first layer is provided on a first electrode side, and the second layer is provided on a second electrode side, and wherein an amount of Nb in the first layer is larger than an amount of Ta in the first layer, wherein an amount of Ta in the second layer is larger than an amount of Nb in the second layer.