Abstract
Under combined bias and temperature stress, the silicon‐silicon dioxide interface is altered by the introduction of more surface states. This effect has been investigated in metal‐oxide‐semiconductor structures formed by a variety of oxidizing, annealing and metalizing procedures. In most cases, stress of 106 V/cm at 300°C caused a surface‐state peak to appear in the lower half of the bandgap. The surface‐state vs. energy curves vary with the oxidation conditions, but they are reproducible when sample preparation is reproduced. The influence of the following parameters was investigated: dry oxygen and steam oxidation, Cr‐Au and Al contacts, e‐gun and filament evaporation and post‐metalization annealing. The surface‐state density increases linearly with applied field, and it increases in proportion to the logarithm of time. The nature of the distribution also depends on the annealing procedures, and on the contact metal.