Keithley 4200A-SCS - Page 1190

Model 4200A
-SCS Parameter Analyzer Reference Manual Appendix D: Using a Model 82 C-
V System
4200A-901-01 Rev. C / February 2017 D-49
Series resistance
The series resistance, R
SERIES
, is an error term that can cause measurement and analysis errors
unless this series resistance error factor is taken into account. Without series compensation,
capacitance can be lower than normal, and C-V curves can be distorted. The software compensates
for series resistance using the simplified three-element model shown in the simplified model below. In
this model, C
OX
is the oxide capacitance. CA is the capacitance of the accumulation layer. The series
resistance is represented by R
SERIES
.
Figure 612: Simplified model to determine series resistance
From Nicollian and Brews 224, the correction capacitance, C
C
, and corrected conductance, G
C
, are
calculated as follows:
and:
Where:
• a = G
M
- (G
2
M
+ ω
2
C
2
M
) R
SERIES
• C
C
= series resistance compensated parallel model capacitance
• C
M
= measured parallel model capacitance
• G
C
= series resistance compensated conductance
• G
M
= measured conductance
• R
SERIES
= series resistance