Patent ID: 8026143

Claim:
A method of manufacturing a MOS field effect transistor with a high permittivity gate dielectrics layer, comprising: forming first high permittivity gate dielectrics on a silicon dioxide (SiO 2 ) film or a silicon oxynitrided (SiON) film; forming second high permittivity gate dielectrics having a relative permittivity constant being different from that of the first high permittivity gate dielectrics; and forming a metal electrode film on the second high permittivity gate dielectrics, wherein the first and second high permittivity gate dielectrics constitute the high permittivity gate dielectrics layer, wherein the formation of the first high permittivity gate dielectrics comprises: a first step for depositing a first metal film containing Hf on the silicon dioxide (SiO 2 ) film, or silicon oxynitrided (SION) film, by means of a sputtering method using a metal target in an atmosphere where oxidation reaction of metal atoms hardly occurs; and a second step for forming the first high permittivity gate dielectrics of HfSiO by subjecting the first metal film and the silicon dioxide (SiO 2 ) film or the silicon oxynitrided (SiON) film to a thermal oxidation treatment at a temperature of 500° C. to 900° C., wherein the formation of the second high permittivity gate dielectrics comprises: a third step for depositing a second metal film of Ti on the first high permittivity gate dielectrics of HfSiO, by means of a sputtering method using a metal target of Ti in an atmosphere where oxidation reaction of metal atoms hardly occurs; and a fourth step for forming the second high permittivity gate dielectrics of TiO 2 by subjecting the second metal film of Ti to a thermal oxidation treatment at a temperature lower than 500° C., and wherein a EOT (Equivalent Oxide Thickness) of the high permittivity gate dielectrics layer is 1.0 nm or less and a leakage current thereof is 10 −1 A/cm 2 or less, and the first to fourth steps are sequentially performed without exposing the first and second metal films and the resultant first and second high permittivity gate dielectrics to atmospheric air.