Submicron meter polycrystalline-SiGe thin-film transistor (TFT) device with tunneling field-effect-transistor (TFET) structure has been studied With scaling the gate length down to 1 mu m the poly-SiGe TFT device with conventional metal-oxide-semiconductor field effect transistor (MOSFET) structure would be considerably degraded which exhibits an off state leakage of about 04 nA/mu m at a drain bias of 3 V The short channel effect would tend to cause the source/drain punch-through and also increase the lateral electric field within the channel region thus enhancing the carried field emission via trap states The TFET structure can be employed to alleviate the short channel effect in poly SiGe TFT device As a result even for a gate length of only 05 gm the resultant poly-SiGe TFT-TFET device can exhibit good electrical characteristics with an off-state leakage smaller than 0 1 pAhim and an on/off current ratio of about 9 orders at a drain bias of 3 0 V (C) 2010 Elsevier Ltd All rights reserved