IN-SITU MEASUREMENTS OF INTERFACE STATES AT SILICON SURFACES IN FLUORIDE SOLUTIONS

The energetics and kinetics of processes involving interface states at silicon (111) surfaces in aqueous fluoride solutions were determined using in situ impedance spectroscopy. In the dark, we observe electric ally active surface states with densities in the range 2 X 10(10) to 1 X 10(12) cm(-2) dependent on the surface chemistry. The surface state s are physically the same, independent of pH, with a capture cross sec tion of 1 X 10(-16) cm(2). Measurements under illumination show that r ecombination occurs at different interface states than those observed in the dark.