Narrow-Width Effects in 28-nm FD-SOI Transistors Operating at Cryogenic Temperatures

In this paper, we present on the cryogenic characterization of short channel 28-nm FD-SOI nMOS and pMOS transistors having widths of the
$1 ~\mu \text{m}$
and
$0.08 ~\mu \text{m}$
at temperatures ranging from T = 300 K down to T = 10 K. We report, for the first time, the alarming concerns that the narrow-width effect imposes on the overall performance of highly scaled FD-SOI technologies, at temperatures below T = 77 K. The performance comparison between nMOS and pMOS devices is based on their drain current, threshold voltage, transconductance, subthreshold slope, low field mobility and total resistance. Our results show that the sensitivity of narrow width effects towards drain current, threshold voltage and total resistance is smaller in pMOS as compared to nMOS. The effective improvement in transconductance is also significantly larger in narrow width pMOS in comparison to their nMOS counterparts. A substantial degradation of subthreshold swing, total resistance and low field mobility is also observed in narrow nMOS devices, which questions the width scaling benefits of these technologies at cryogenic temperatures.