Measurement of MOSFET C-V Curve Variation Using CBCM Method

The test circuit, in which the cells including CBCMs (charge-based capacitance measurements) are arrayed in matrix shape, is developed to measure MOSFET capacitance variation. By adjusting the bias condition of the test circuit, it is able to obtain C-V curves for many MOSFETs. Additionally, a variation of threshold voltage is extracted from the estimated C-V curve variation. The obtained threshold voltage variations are close to those which are obtained from current-voltage characteristics.