We report on n-channel tunneling field-effect transistors (TFET) with a tensile strained Si channel and a compressively strained Si0.5Ge0 5 source. The device shows good performance with an average subthreshold swing S of 80 mV/dec over a drain current range of more than 3 orders of magnitude. We observed that the on-current increases exponentially with the back gate voltage. At a back gate voltage of 8 V. the on-current was enhanced by a factor of 1.6. The back gate also improves the on/off current ratio. Low temperature measurements show a slightly temperature dependent S. characteristic for a tunneling dominated device. (c) 2012 Elsevier Ltd. All rights reserved.