Keithley 4200A-SCS - Page 1162

Model 4200A
-SCS Parameter Analyzer Reference Manual Appendix D: Using a Model 82 C-
V System
4200A-901-01 Rev. C / February 2017 D-21
Formulas for the system82-cvsweep test (simcv project) are shown in Formulas for system82-
cvsweep test (simcv project) (on page D-21).
Formulas for ctsweep test (lifetime project) are shown in Formulas for ctsweep test (lifetime
project) (on page D-23)
Formulas for cvsweep test (stvs project) are shown in Formulas for cvsweep test (stvs project) (on
page D-23).
The values for constants used in the formulas are in the Constants area in the Formulator. The
constants include:
• Area, with a value of 0.012 mm
2
• eOX, with a value of 3.4e-013 F/cm
• eS, with a value of 1.04e-012 F/cm
Refer to Simultaneous C-V analysis (on page D-47) for details on simultaneous C-V theory and the
formulas.
Formulas for system82-cvsweep test (simcv project)
Formula name Description and formula
VGS
Gate voltage:
VGS =
−
VSub
RS
Serial resistance calculated by high frequency CV:
RS = (AT(MAVG(G_OR_R,5)/(WF*MAVG(CHF,5)),MAXPOS(MAVG(CHF,5))))^2/
((1+(AT(MAVG(G_OR_R,5)/(WF*MAVG(CHF,5)),MAXPOS(MAVG(CHF,5))))^2)
*(AT(MAVG(G_OR_R,5),MAXPOS(MAVG(CHF,5)))))
AR
Intermediate parameter for calculation of CC:
AR = G_OR_R-(G_OR_R^2+(WF*CHF)^2)*RS
CC
Corrected high frequency capacitance by compensating serial resistance:
CC = ((G_OR_R^2+(WF*CHF)^2))*CHF/(AR^2+(WF*CHF)^2)
HOFFSET
Offset for high frequency capacitance (entered by user):
HOFFSET = 0
QGAIN Gain for quasistatic capacitance (entered by user):
QGAIN = 1
QOFFSET Offset for quasistatic capacitance (entered by user):
QOFFSET = 0
CQADJ
Adjusted quasistatic capacitance by using QGAIN and QOFFSET:
CQADJ = QGAIN*CQS+QOFFSET
HGAIN
Gain for calculated high frequency capacitance that is calculated:
HGAIN = AT(MAVG(CQS,5)/MAVG(CC,5),MAXPOS(MAVG(CC,5)))
CHADJ
Adjusted high frequency capacitance by using HGAIN and HOFFSET:
CHADJ = HGAIN*CC+HOFFSET
COX
Oxide capacitance:
COX = MAX(MAVG(CHADJ,5))+1E-15
CMIN Minimum capacitance from high frequency:
CMIN = MIN(MAVG(CHADJ,5))+1E-15
TOXNM
Calculated thickness of oxide (in nanometers):
TOXNM = 1E7*AREA*EOX/COX
INVCSQR
Inversed square of high frequency capacitance:
INVCSQR = 1/(MAVG(CHADJ,5))^2