Effects of interface roughness scattering on RF performance of nanowire transistors

As the metal oxide semiconductor field effect transistor (MOSFET) has been scaled down to the nano-meter regime, it has become difficult to further scale the planar type MOSFET [1]. As an alternative device structure, a nanowire transistor has been proposed to the scientific community. Not only that it can suppress the short channel effects in a logic device, it is also a good candidate for a RF device due to its high transconductance and high cut-off frequency [2]. Because of the volume inversion effects, the mobility of electrons in nanowire structures is improved [3], which results in a high transconductance. The capacitance of a nanowire transistor becomes smaller due to a larger effective oxide thickness caused by the volume inversion phenomenon [3]. This paper addresses the effects of interface roughness scattering in a nanowire transistor especially on the cut-off frequency through a full band quantum mechanical simulation [4] of atomistically generated nanowire structure as depicted in Fig. 1.