Mobility improvement in nanowire junctionless transistors by uniaxial strain

Improvement of current drive in n- and p-type silicon junctionless metal-oxide-semiconductor-field-effect-transistors (MOSFETs) using strain is demonstrated. Junctionless transistors have heavily doped channels with doping concentrations in excess of 10¹⁹ cm^-3 and feature bulk conduction, as opposed to surface channel conduction. The extracted piezoresistance coefficients are in good agreement with the piezoresistive theory and the published coefficients for bulk silicon even for 10 nm thick silicon nanowires as narrow as 20 nm. These experimental results demonstrate the possibility of enhancing mobility in heavily doped silicon junctionless MOSFETs using strain technology.