NANOMETER-SCALE CREATION AND CHARACTERIZATION OF TRAPPED CHARGE IN SIO2-FILMS USING BALLISTIC-ELECTRON-EMISSION MICROSCOPY

Electron injection into similar to 25 nm thick SiO2 films in Pt/SiO2/S i structures using ballistic electron emission microscopy (BEEM) is fo und to produce a local suppression in the BEEM current, which is at le ast partly due to electron trapping in the SiO2 film. Measured variati ons in the BEEM threshold voltage with the voltage applied across the SiO2 film can be used to estimate the local trapped electron density a nd the centroid location, which agree with macroscopic measurements. O ur measurements indicate that BEEM can be sensitive to very small numb ers of electrons trapped in buried SiO2 films.