CONTACTLESS CHARACTERIZATION OF THERMALLY OXIDIZED, AIR-EXPOSED AND HYDROGEN-TERMINATED SILICON SURFACES BY CAPACITANCE-VOLTAGE AND PHOTOLUMINESCENCE METHODS

Contactless and nondestructive characterization of the electrical prop erties of the free surfaces of single-crystalline silicon wafers is ac complished for the first time by combined use of the contactless metal -insulator-semiconductor (MIS) capacitance-voltage (C-V) technique and the photoluminescence surface state spectroscopy (PLS(3)) technique. The thermally oxidized, air-exposed and hydrogen-terminated silicon (1 11) surfaces were investigated. Thick thermally oxidized surfaces show ed well-behaved characteristics with a minimum of a broad U-shaped int erface state density (N-ss) distributions in a range of 10(10) cm(-2) eV(-1). On the other hand, the air-exposed Si surface exhibited a GaAs MIS-like behavior with strong Fermi level pinning near the charge neu trality level E(HO) caused by a narrow U-shaped state distribution. Su rprisingly, hydrogen-terminated surfaces showed even stronger Fermi le vel pinning at E(o) = E(c) - 0.43 eV due to high density of amphoteric discrete state which may be due to silicon dangling bonds.