Question 8. Finding the Oxide Charge Density at the Flatband Condition and at the Midgap Condition

    Recall from the former discussion that the flatband voltage could be calculated by the following equation:

                                  (1)   

    Where 

      (2)

    Therefore, replacing equation 2 to equation 1, Q can be found to be:

  (3)

    i.e.

 (4)

    In mid gap condition, the ideal case for the mid gap voltage should be:

   (5)

    By replacing all the figures, the result for mid gap voltage is 0.454 V. Then the total charge can be calculated by:

(6)

    Thus, the charge density is

  (7)