Background:
In state-of-the-art nanometer metal-oxide-semiconductor-field-effect- transistors (MOSFETs),
optimization of timing characteristic is one of the major concerns in the design of modern digital integrated circuits.
Objective:
This study proposes an effective back-gate-biasing technique to comprehensively investigate the timing and its
variation due to random dopant fluctuation (RDF) employing Monte Carlo methodology.
Methods:
To analyze RDF-induced timing variation in a 22-nm complementary metal-oxide semiconductor (CMOS)
inverter, an ensemble of 1000 different samples of channel-doping for negative metal-oxide semiconductor (NMOS) and
positive metal-oxide semiconductor (PMOS) was reproduced and the input/output curves were measured. Since back-gate
bias is technology dependent, we present in parallel results with and without VBG.
Results:
It is found that the suppression of RDF-induced timing variations can be achieved by appropriately adopting
back-gate voltage (VBG) through measurements and detailed Monte Carlo simulations. Consequently, the timing
parameters and their variations are reduced and, moreover, that they are also insensitive to channel doping with back-gate
bias.
Conclusion:
Circuit designers can appropriately use back-gate bias to minimize timing variations and improve the
performance of CMOS integrated circuits.
