QBD
QBD is the term applied to the charge-to-breakdown measurement of a device and is a method used to determine reliability of gate oxides in MOS devices. Voltage is applied to the MOS structure to force a controlled flow of current through the oxide; i.e. to inject controlled amount of charge into the oxide. By measuring the time after which voltage drops to zero (oxide breakdown occurs) and knowing injected current, the charge needed to break the oxide is determined.
This accumulated oxide charge is defined as:
Where
t = time.
Tbd = measurement time at the step just prior to breakdown.
QBD (originally Queensland Book Depot) is also the name of a large chain of bookshops in Australia.
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