Model 4200A-SCS Parameter Analyzer Reference Manual
Section 4: Multi-frequency capacitance-voltage unit
4200A-901-01 Rev. C / February 2017
4-89
Since the junction can be modeled after a parallel plate capacitor, the junction capacitance is
calculated as follows:
Where:
•
C = junction capacitance (F)
•
ε
s
= semiconductor permittivity (1.034e-12 F/cm for silicon)
•
A = area of junction (cm
2
)
•
W = depletion width (cm)
However, unlike the parallel plate capacitor, the depletion layer width (
W
) is not a constant, but is
dependent on the applied voltage. From the previous equation the depletion depth,
W
, can be
calculated as follows:
From the measured capacitance and the voltage, the doping density can be calculated as follows:
Where:
•
N(W) = doping density (cm
-3
)
•
A = area of junction (cm
2
)
•
C = junction capacitance (F)
•
ε
s
= semiconductor permittivity (1.034e-12 F/cm for silicon)
•
q = electron charge (1.60219e-19 C)
•
V = junction voltage
