An ultra high-speed semiconductor device has a high-K dielectric gate insulator
layer, wherein spread of impurities to a Si substrate from a gate electrode through
the high-K dielectric gate insulator layer, and spread of oxygen and metallic elements
from the high-K dielectric gate insulator layer to the Si substrate or the gate
electrode are suppressed by arranging the high-K dielectric film sandwiched by
nitrogen atomic layers on the Si substrate that is covered by an oxygen atomic layer.
