Advanced CV-Measurements
and Calibration at the Wafer-Level
Quick How-To Reference

Company Confidential

C-V Instrumentations
Agilent 4980A

Keithley 4200-SCS

Agilent 4294A

Keysight E4990A

Keysight B1500A

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2

C-V Instrumentations: Auto-Balancing Bridge Method
Agilent 4980A

Agilent 4294A

Keysight E4990A

Keithley 4200+CVU : 1 kHz to 10 MHz | DC Bias : Up to 30V

Agilent B1500+MFCMU : 1 kHz to 5Mz | DC Bias : Up to 25VAgilent 4980A : 20 Hz to 2 MHz | DC Bias : Up to 40VAgilent 4294A : 40 Hz to 110MHz |DC Bias : Up to 40V

Agilent 4981A : 120 Hz to 1 MHz | DC Bias : NoneKeithley 4200-SCS

Keysight B1500A

Keysight E4990A : 20Hz to 120MHz | DC Bias : Up to 40V - NEW

Company Confidential3Auto-Balancing Bridge Method (ABB)
Current Meter

Potential Meter to Lock phaseof the of the measured signal

AC of the test
signal applied tothe DUT

Voltage Monitor By
Potential Meter

Picture courtesy: Keysight

Keep “0V” in AC manner by active
feedback. So called “VirtualGround”, not actual ground.

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4ABB: Sources of Errors

Picture courtesy: Keysight

Mutualinductance
StrayCapacitances

ResidualImpedance

 Residual impedance in the cables
 Stray capacitance between cables or to ground Mutual inductance caused by the current flow between adjacent cables

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5ABB: Sources of Errors

Hp

Hc

CDUT

Lp

Lc

Eliminate cable resistance from the measurements

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6

MPI Solutions: Kelvin Probe Arm

Eliminate the effects of the residual impedance

Shielding the cables to eliminate stray capacitanceVertical self-leveling for easy tip replacement2M |1M Direct Impedance Analyzer BNC to SSMB toProbe with no disturbanceEasy to reconnect for different IV/CV/PIV
measurements

ShieldEnclosure
VersionFor Ultra Low noise and accurate IV/CV Measurementin open and Shield Environment SystemForce

Open |Dark-Box
versionPA-K50-SE
Kelvin Probe with DualTriax

Vertical selfleveling

Sense

Company Confidential7

MPI Solutions: V-Ground ConnectorProvide 4-TP Connection for accurate CV at higher
frequency >2MHz



Eliminate the mutual inductance between cables

Provides the shortest connection for virtual groundIncluded in the Kelvin Probe

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8

On wafer verification on Calibration Substrate■

System needs to be calibrated with Open/Short orOpen/Short/Load calibration method from the CV instruments
prior to any measurement■

MPI calibration substrates include required standards and are
qualified using the NIST methodology●●■

loads are accurately trimmed to 50 Ohm with < 0.3% error
reference capacitance for CV calibration verification

Recommended substrate models:●●AC-3 for DUT pads < 50 um x 50 um
AC-5 for lager pads

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9Calibration Substrates Qualified: AC-2 Example

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10Calibration Substrates Qualified: NIST methodology

Company Confidential11AC-3: Open Standards

C=7 fF

Company Confidential12AC-3: Open Standards (Optional)

C1=27 fF (optional)

Company Confidential13AC-3: Short Standards

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14AC-3: Calibration Loads

50 Ohm Load, < 0.3% accuracy

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AC-3: Verification Capacitances

C6=715 fF

C2=60 fF

C3=120 fF

C4=245 fF

C5=450 fF

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16Thank you