This letter presents experimental results on tunneling field-effect transistors featuring arrays of Ω-gated uniaxially strained and unstrained silicon nanowires. The gate control of a SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /poly-Si gate stack is compared with a high- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> /metal gate stack. Steep inverse subthreshold slopes down to 76 mV/dec and relatively high on-currents were achieved with the combination of high- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> /metal gate and strained silicon nanowires. We observed negative differential conductance in the output characteristics, which we attribute to hot-carrier effects in the strong electric fields at the reverse-biased tunnel junction.