Patent ID: 7388785

Claim:
A method for extracting the spatial distribution of charge (N nt ) stored in a charge-trapping layer of a semiconductor device having a channel underneath the charge trapping layer with an effective length L eff , comprising: a) determining a varying base-level voltage charge pumping curve, b) determining a varying top-level voltage charge pumping curve, and c) combining data from the charge pumping curves to obtain the spatial distribution, wherein step c) comprises the steps of: d) establishing a relation between a charge pumping current I cp and a calculated channel length L calc of the semiconductor device by reconstructing spatial charge distribution estimates from the charge pumping curves for multiple values of the charge pumping current I cp , e) obtaining from the multiple values of I cp the value for which the corresponding calculated channel length L calc is substantially equal to the effective channel length L eff of the semiconductor device, and f) reconstructing the spatial charge distribution from the charge pumping curves using the value of I cp obtained in step e).