Technical data

5- 12 Agilent 41000 Administration Guide, Edition 3
Measurement Techniques
Low Current Measurements
Hold Time
Dielectric absorption is considerable for the low current measurement. It may be
unexpected current caused by rapid voltage changes. To measure low current properly, it is
important to wait until when this transitional current settles down. So, the low current
measurement should be performed with the reasonable hold time setting. To find the
reasonable hold time, perform the dielectric absorption current measurement as shown
below.
1. Make open state at the end of the measurement path for the all output ports.
The measurement path should include the probe card, manipulator, or something to
contact pad/terminal of device under test (DUT).
2. Connect the current measurement path to a source monitor unit (SMU). Connect
unused paths to the ground unit (GNDU) or other SMU.
3. Set the dielectric absorption current measurement condition; integration time,
measurement range, output voltage, compliance, and so on.
• The integration time should be enough long (e.g. 16 power line cycles). And the
value must be the same as the value set for the actual measurement.
• The measurement range, output voltage, and compliance value must be the value
(e.g. 10 pA, 10 V, 10 mA) used for the actual
DUT measurement.
• All unused source outputs must be 0 V.
4. Enable time stamp function.
5. Apply voltage and reset time stamp. And then, perform current measurement and
record data (current and time stamp data). And repeat the current measurement until the
time stamp value is over 100 sec, for example.
6. Find the reasonable hold time from the measurement result. Or, plot the measurement
data on the current-time graph, and find the reasonable hold time.
Figure 5-7 Effect of Electric Absorption
A
Open
Cs
C1
R1
Cn
Rn
A) Equivalent circuit when open
B) I-t characteristics observed
I
t
Pure leakage current
Dielectric absorption current
Noise
Hold time