Agilent Technologies 4155C User Manual page 231

C-V Measurement Characteristics
Capacitance is calculated value derived from the following equation:
C=dQ/dV
dQ is the charge when dV, the step voltage (QSCV measurement voltage), is applied
by the SMU; dQ is derived from the measurement current (amps) and the integration
time (seconds).
Maximum value Maximum measurement value depends on the current range,
integration time, and step voltage (QSCV measurement
voltage).
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•
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Accuracy Capacitance calculation accuracy is dependent on accuracy of
the current measurement and voltage measurement, and the
stray capacitance and leakage current of measurement path etc.
(refer to supplemental data shown below).
Zero Offset Cancels stray capacitance of the fixtures and test leads.
Current
Compensation Cancels the influence of the leakage current to the capacitance
measurement.
Capacitance Calculation Accuracy (Supplemental Data).
Accuracy is derived from the current range, voltage range, capacitance
measurement and leakage current measurement integration times, and the guard
capacitance of cabling and the QSCV measurement voltage. The information in
Table 8-11 and Table 8-12 is based on the following conditions:
• Voltage range: 20 V
• QSCV measurement voltage: 100 mV
• Guard capacitance: 100 pF
• Equivalent parallel resistance of DUT: 10
• The ratio of integration times for capacitance measurement and leakage current
measurement is 1:1.
Agilent 4155C/4156C User's Guide Vol.1, Edition 11
Current range (4156C): 10 pA, 100 pA, 1 nA, 10 nA
Current range (4155C): 1 nA, 10 nA
Voltage range: 2 V, 20 V, 40 V, 100 V, 200 V
15
Specifications
Ω
Functions
8-23