Matching Properties of Deep Sub-Micron MOS Transistors examines this
interesting phenomenon. Microscopic fluctuations cause stochastic
parameter fluctuations that affect the accuracy of the MOSFET. For
analog circuits this determines the trade-off between speed, power,
accuracy and yield. Furthermore, due to the down-scaling of device
dimensions, transistor mismatch has an increasing impact on digital
circuits. The matching properties of MOSFETs are studied at several
levels of abstraction:
A simple and physics-based model is presented that accurately describes
the mismatch in the drain current. The model is illustrated by
dimensioning the unit current cell of a current-steering D/A converter.
The most commonly used methods to extract the matching properties of a
technology are bench-marked with respect to model accuracy, measurement
accuracy and speed, and physical contents of the extracted parameters.
The physical origins of microscopic fluctuations and how they affect
MOSFET operation are investigated. This leads to a refinement of the
generally applied 1/area law. In addition, the analysis of simple
transistor models highlights the physical mechanisms that dominate the
fluctuations in the drain current and transconductance.
The impact of process parameters on the matching properties is
discussed.
The impact of gate line-edge roughness is investigated, which is
considered to be one of the roadblocks to the further down-scaling of
the MOS transistor.
Matching Properties of Deep Sub-Micron MOS Transistors is aimed at
device physicists, characterization engineers, technology designers,
circuit designers, or anybody else interested in the stochastic
properties of the MOSFET.
