Variation Aware Performance Analysis of TFETs for Low-Voltage Computing

Abstract

Tunnel field-effect transistors (TFETs) can outperformMOSFETs in low power electronics due its low leakagecurrent and excellent threshold swing. In recent years, theapplication of TFETs in the design of sub-threshold cores havebeen proposed, operating at few hundred millivolts. Howeverprocess induced variations need to be considered while assessingthe achievable benefits of TFETs at such low voltages. Also, the non-idealities associated with distribution and regulation ofsuch low supply voltages needs to be modeled. Here we presentthe analysis of process variations effect on device performancemetrics (Energy consumption, Operating frequency) of digitaldesign comprising AlGaSb/InAs Hetrojunction TFETs (HTFET),InAs/Si HTFETs and MOFETs. Our evaluation based on calibratedTFET compact models show that TFET circuits are lessaffected than the MOSFET counterparts from process variation. The energy-delay product of TFET and CMOS is compared, considering process variations and supply voltage noise. Further, a feasibility study of low voltage, low ripple supply distributionfor sub-threshold TFET blocks based on distributed Digital LowDrop Out (LDO) is presented.