Keithley S530 User Manual

S530 Parametric Test System Test Subroutine Library User's Manual Section 3: Test subroutine library reference
S530-907-01 Rev. A / September 2015 3-59
rvdp
This subroutine makes a four-terminal van der Pauw measurement.
Usage
double rvdp(int pin1, int pin2, int pin3, int pin4, int sub, double itest, double
*ratio)
pin1
Input
First pin on the device
pin2
Input
Second pin on the device
pin3
Input
Third pin on the device
pin4
Input
Fourth pin on the device
sub
Input
The substrate pin of the device
itest
Input
The forced current, in amperes
ratio
Output
The ratio of resistances (R
S
)
Returns
Output
The estimated sheet resistance:
 0.0 = Measured voltage is < 0.002 V or itest = 0.0
 2.0E+21 = Measured voltage is within 98 % of the voltage limit
Details
This subroutine estimates the sheet resistance of a four-terminal sample using the standard
technique of forcing current through two adjacent pins and measuring the voltage developed across
the two remaining pins. The device connections are then shifted 90 degrees and the measurements
are repeated.
The sheet resistance is calculated as the average of the two resistances. The difference between the
two orientations is returned in the ratio variable. See the schematic for the correct pin orientation on
the sample.
If a positive substrate pin is specified, the substrate is grounded. If a positive substrate pin is not
specified, the substrate is left floating.
A delay is incorporated into the rvdp subroutine; this delay is the calculated time required for a stable
forcing of itest with a 30 V voltage limit.
Source-measure units (SMUs)
 SMU1: Forces itest, default voltage limit
 SMU2: Set to VMTR, measures voltage

Keithley S530 Specifications

General

Brand	Keithley
Model	S530
Category	Test Equipment
Language	English