Patent ID: 7042055

Claim:
A metal-insulator-semiconductor field effect transistor (MISFET) comprising a gate dielectric film formed from a high dielectric constant material which has a relative dielectric constant higher than that of a SiO 2 gate dielectric film and is in an amorphous state and having an equivalent oxide thickness (EOT) of silicon dioxide (t EOT ) of 2 nm or less, given by a formula t EOT =t ox ·∈ SiO2 /∈ ox , where ∈ SiO2 is a relative dielectric constant of silicon dioxide, ∈ ox is a relative dielectric constant of said gate dielectric film, and t ox is an average of the physical thickness of said gate dielectric film, wherein a ratio (Δ/t ox ) of the difference (Δ) between the maximum and the minimum of said physical thickness of said gate dielectric film present on the upper side of a channel portion of said field effect transistor to the average (t ox ) of said physical thickness is 10% or less.