COCOS metrology enables gate dielectrics to be quickly monitored in a non-contact manner for all wafer sizes including 300mm. This approach has been developed during the last five years and is already implemented in many microelectronic fablines. The method uses corona charging in air to deposit an electric charge on a dielectric thus changing the electric field in the dielectric and in the semiconductor. The response is measured in a non-contact manner by using a contact potential difference, VCPD, in the dark and under strong illumination. This measurement gives the voltage drop across the oxide. VOX and the surface barrier, VSB, as a function of the corona charge dose, ΔQC. These basic relationships are then used in a very straightforward manner to determine the flat band voltage, VFB, the total charge required to achieve the flat band condition, QTOT and the interface trap spectra, DIT, across the silicon bandgap in an energy range from flat band to deep inversion. Measurements of VCPD vs. ΔQC under a...