Random dopant fluctuation (RDF) is a form of process variation resulting from variation in the implanted impurity concentration. In
MOSFET
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a type of field-effect transistor (FET), most commonly fabricated by the controlled oxidation of silicon. It has an insulated gate, the voltage of which d ...
transistors, RDF in the channel region can alter the transistor's properties, especially
threshold voltage. In newer process technologies RDF has a larger effect because the total number of
dopants is fewer, and the addition or deletion of a few
impurity atom
In chemistry and materials science, impurities are chemical substances inside a confined amount of liquid, gas, or solid, which differ from the chemical composition of the material or compound. Firstly, a pure chemical should appear thermody ...
s can significantly alter transistor properties. RDF is a local form of process variation, meaning that two neighbouring transistors may have significantly different dopant concentrations.
[ Asenov, A. Huang]
Random dopant induced threshold voltage lowering and fluctuations in sub-0.1 μm MOSFET's: A 3-D “atomistic” simulation study
Electron Devices, IEEE Transactions, 45 , Issue: 12
References
Semiconductor device fabrication
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