Ultrathin zirconium silicate film with good thermal stability for alternative gate dielectric application

Zirconium silicate (ZrSixOy) films have been sputtered by comagnetron-reactive sputtering. The composition of ZrSixOy has been controlled by adjusting the sputtering powers of Si and Zr targets to achieve various effective dielectric constants. The sputtered silicate layers showed low equivalent oxide thickness of 14.5 Angstrom with a low leakage of 3.3x10(-3) A/cm(2) at -1.5 V relative to flat band voltage. The silicate films also exhibited good high-temperature stability and smooth interfacial properties on silicon substrate. (C) 2000 American Institute of Physics. [S0003-6951(00)01337-1].