Patent Document ID: 9069035
Application ID: 13333433
Patent Flag: 1

Claim One:
1. A method of characterizing a semiconductor device from conductive-probe measurements performed on a semiconductor wafer from which the device is manufactured, said wafer including a p-type semiconductor layer and an n-type semiconductor layer defining a p-n junction, the method comprising the following steps: applying electrical stimuli to the wafer through a probe in direct contact with one of said semiconductor layers to produce conductive-probe measurement data; fitting a current-voltage curve (I-V) model to said conductive-probe measurement data, said model expressing a current-voltage relationship as a function of resistance; and estimating a current-voltage curve (I-V d ) for the device by removing from the (I-V) model resistance effects calculated from data generated by the fitting step; wherein the resistance is assumed variable with current and the resistance is calculated from measurement data points from the equation: R = Δ ⁢ ⁢ V Δ ⁢ ⁢ I where R is resistance, V is voltage, and I is current; wherein the device's forward voltage, ideality factor, resistance and reverse saturation current are calculated from the following set of equations: R i = α I i β + C I ⁡ ( i ) = I 0 ⁢ exp ⁡ ( q ⁡ ( V i - I i ⁢ R i ) nkT ) V d ⁡ ( i ) = I i ⁢ R i + kT q ⁢ n ⁢ ⁢ ln ⁡ ( I i I 0 + 1 ) where V d is the device's forward voltage, I 0 is reverse saturation current, n is ideality factor, and α, β, and C are constant parameters estimated by fitting N current-voltage measurement data points, (I i ,V i ), i=1K N, with a multi-parameter minimization calculation; and wherein said multi-parameter minimization calculation is carried out with the following estimator: Σ ⁡ ( α , β , C , n , I 0 ) = ∑ i = 1 N ⁢ [ w i ⁡ ( I i - I Mi ) 2 + 1 w i ⁢ ( V i - V Mi ) 2 ] where M i refers to said measurement data points, and w i is an empirical weight factor that accounts for the increased sensitivity of the current-voltage curve for the device to current at high current values and to voltage at low current values.