User`s guide

Agilent EasyEXPERT User’s Guide Vol. 2, Edition 1 8-19
Application Library
QSCV Maximum Measurement Value and Accuracy
Measurement Accuracy
NOTE The measurement accuracy is not the specifications but the supplemental data.
Applicable conditions for supplemental data: Leak current compensation function
ON, Offset cancel function ON, QSO mode OFF
The measurement accuracy can be calculated by the following formula:
Measurement accuracy = A (%) + B (F)
A: Reading accuracy. % accuracy of the measured value.
B: Offset accuracy.
where,
Tinteg: Integration time for the capacitance measurement, in seconds
Tleak: Integration time for the leakage current measurement, in seconds
Vstep: QSCV measurement voltage, in V
Rdut: Equivalent parallel resistance of DUT, in 
Cg: Guard capacitance of the measurement path, in F
Ax, Bx, Cx, and Dx values are the constant. For the values, see Table 8-2 to Table
8-4.
Calculation examples of the measurement accuracy are shown in Figure 8-6 through
Figure 8-30. Conditions of the calculation are shown in Table 8-5.
NOTE Settings for the QSCV Measurement Mode
The measurement mode should be selected based on the measurement conditions.
Normal mode is effective for large leakage currents. The 4155C/4156C compatible
mode is effective if the leakage current is low, or the QSCV measurement voltage is
low.
AAp
Bp Cp Tinteg Dp
Tinteg
Tleak
-----------------++
Vstep
---------------------------------------------------------------------------------+=
B
Ao
Rdut
------------
Bo Boc+ Cg Co Coc Cg+ + Tinteg Do Doc Cg+
Tinteg
Tleak
-----------------+
Vstep
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+=