Analysis of the Method for the Flat-Band Voltage Determination on the Capacitance-Voltage Characteristic Inflection Point

Theoretical analysis of relation between the position of the inflection point on the capacitance-voltage characteristic of an ideal (without interface states) metal-insulator-semiconductor structure and its flat-band voltage is provided. The inflection point position is shown to depend on the relation between semiconductor and insulator capacitances and cannot be a universal characteristic. The inflection point and the flat-band point are found to be equal only when the insulator capacitance coincides with the semiconductor flat-band capacitance. The method of determining the true flat-band voltage position on the normalized capacitance value in the inflection point is proposed.