Technical data

Module 13
SPGU Control and Applications
13-18
Three Methods of Charge Pumping
Gate Waveforms
Time
Voltage
Square Pulse
Triangle Pulse
Trapezoidal Pulse
Charge Pumping
Square Pulse
The base of the pulse is stepped from well below gate threshold to well above. At each step, the
substrate leakage current is monitored. The flat part of the resultant curve is proportional to
interface-state density.
Triangle Pulse
The frequency of a constant height triangle pulse is increased in steps. At each step, substrate
leakage is measured. Average interface state density and capture cross-section are measured by this
method.
Trapezoidal Pulse
A fixed height pulse is applied to the gate. By varying the leading/trailing edge of the pulse, you can
plot interface-state density vs energy.