In this ultramodern scenario, low power, less cost and reduced storage devices are in great demand. Because the majority devices operate on a remote power supply, low-power memories are enticing the unified VLSI industry. For reduced power consumption, high energy efficiency circuit, TFET is a feasible alternate to MOSFET as it is a p-type, intrinsic, n-type (p-i-n) diode whose tunnel current drifts amidst of the bands of channel and source having a minimum leakage current and reduced sub-threshold slope (SS). The sole difference between TFET and MOSFET is the switching mechanism: TFETs use band-to-band tunnelling (BTBT), while MOSFETs use thermionic emission. In this survey, various types of TFET structures are described considering analog, linearity and device parameters like on-current (I-ON), SS, off-current (I-OFF), current ratio (I-ON/I-OFF), threshold voltage (V-T) etc., and comparison is done among the designed TFET structures.