Gate-Length Dependence of Vertical GaSb Nanowire p-MOSFETs on Si

The effect of gate-length variation on key transistor metrics for vertical nanowire p-type GaSb metal-oxide-semiconductor field-effect transistors (MOSFETs) are demonstrated using a gate-last process. The new fabrication method enables short gate-lengths (L
_g
= 40 nm) and allows for selective digital etching of the channel region. Extraction of material properties as well as contact resistance are obtained by systematically varying the gate-length. The fabricated transistors show excellent modulation properties with a maximum I
_ON
/I
_OFF
= 700 (V
_GS
= -0.5 V) as well as peak transconductance of 50 μS/μm with a linear subthreshold swing of 224 mV/dec.