Field Effect‐Capacitance Analysis of Surface States on Silicon

The capacitance of a space charge layer, induced on a semiconductor surface, is analyzed to obtain information on the charge of surface states. Capacitance measurements on silicon‐silicon oxide‐metal combinations are presented, and these indicate a quasi‐continuous spectrum of surface states with a density of approximately 1 × 10 12 states/cm 2 · eV in the range 0.2 to 0.8 eV above the valence band for both, p ‐ and n ‐type samples, and a total density of 1.7 × 10 12 states/cm 2 . Advantages and limitations of the capacitance‐method are discussed.