ABSTRACT
A MOS capacitor (see figure opposite) is a sandwich of a metal electrode insulated by a film of silicon dioxide from a layer of P-type silicon. If a positive voltage is applied to the metal electrode, a low energy well is created close to the interface between the silicon dioxide and the silicon. Any free electrons will be attracted to this well and stored. They can then be moved on to an adjacent cell if a deeper depletion region is created there.
