Keithley 4200A-SCS

Model 4200A
-SCS Parameter Analyzer Reference Manual Section 4: Multi-frequency capacitance-
voltage unit
4200A-901-01 Rev. C / February 2017 4-75
6. The mobile ion charge is calculated as follows:
Where:
• Q
m
= mobile ion charge (C)
• V
fb2
= flatband voltage measured second time after temperature stress (V)
• V
fb3
= flatband voltage measured third time with opposite bias polarity (V)
• C
OX
= oxide capacitance (F)
• A = gate area (cm
2
)
The mobile ion concentration is related to the mobile ion charge through the following equation:
Where:
• N
mi
= mobile ion concentration
• Q
m
= mobile ion charge (C)
• q = electron charge
moscap-mobile-ion connections
The next figure shows the basic test configuration. Refer to 4210-CVU connections (on page 4-5) for
details on connections to a semiconductor wafer. Only use the supplied (red), same length 100 Ω
SMA cables for connections to the 4210-CVU.
After making or changing connections, be sure to use the Confidence Check diagnostic tool and do
connection compensation tests. Refer to Confidence Check (on page 4-19) and Connection
compensation (on page 4-10) for details.
Figure 131: Basic configuration for mobile ion testing