Semiconductors have a dielectric
made of an oxide between the transistor channel and the gate. In order to achieve high switching speeds, such a dielectric should be extremely thin. #0 The materials for the oxide are called high-k die lectrics as soon as their permittivity exceeds the value of 4. In semiconductor technology, the Equivalent Oxide Thickness (EOT) has proven itself as a comparative measure. The EOT value is a comparative value that indicates how thick a silicon dioxide layer would have to be to have the same dielectric constant as the high-k dielectric.