Keithley 4200A-SCS - Page 1202

Model 4200A
-SCS Parameter Analyzer Reference Manual Appendix D: Using a Model 82 C-
V System
4200A-901-01 Rev. C / February 2017 D-61
G/nI computation
Where:
• G = generation rate (s
-1
)
• ε
S
= permittivity of semiconductor (F/cm)
• A = gate area (cm
2
)
• N
AVG
= average doping concentration (cm
-3
)
• C
OX
= oxide (maximum) capacitance (pF)
• C
t(i+1)
= (i+1) value of measured C-t capacitance (pF)
• C
t(i-1)
= (i-1) value of measured C-t capacitance (pF)
• n
I
= intrinsic carrier concentration (cm
-3
)
• t
int
= time interval between C-t measurements (s)
• i = [2, #Rdgs-1]
w - wF computation
Where:
• w = depletion depth (cm)
• w
F
= equilibrium inversion depth (cm)
• ε
S
= permittivity of semiconductor (F/cm)
• A = gate area (cm
2
)
• C
ti
= i(th) value of measured C-t capacitance (pF)
• C
MIN
= equilibrium minimum capacitance (pF)
Determining generation velocity and generation lifetime
The generation lifetime, τ
G
is equal to the reciprocal of the slope of the linear portion of the Zerbst
plot, while the generation velocity, s, is the y-axis (G/n
I
) intercept of the same linear section of the
Zerbst plot.