Experimental and theoretical explanation for the orientation dependence gate-induced drain leakage in scaled MOSFETs

Abstract

In this work we provide a compelling experimental and theoretical explanation for the low GIDL currents that occur due to band to band (b2b) tunneling in MOSFETs with [100] (45° rotated) channel direction compared to [110] oriented devices. In measurements on bulk Si wafers, we clearly show a factor of ∼3x decrease in tunneling current for (001) wafers compared to (011) or (111) wafers supporting the GIDL observations. Rigorous calculations of complex band structure for the three directions reveal that the light hole band dominates the tunneling action integral, supporting our measurements and accounting for the GIDL data. © 2009 IEEE.