Reduction of leakage current in In0.53Ga0.47As channel metal-oxide-semiconductor field-effect-transistors using AlAs0.56Sb0.44 confinement layers

Abstract

We compare the DC characteristics of planar In0.53Ga0.47As channel MOSFETs using AlAs0.56Sb0.44 barriers to similar MOSFETs using In0.52Al0.48As barriers. AlAs0.56Sb0.44, with ∼1.0 eV conduction-band offset to In0.53Ga0.47As, improves electron confinement within the channel. At gate lengths below 100 nm and VDS = 0.5 V, the MOSFETs with AlAs0.56Sb0.44 barriers show steeper subthreshold swing (SS) and reduced drain-source leakage current. We attribute the greater leakage observed with the In0.52Al0.48As barrier to thermionic emission from the N + In0.53Ga0.47As source over the In0.53Ga0.47As/In0.52Al0.48As heterointerface. A 56 nm gate length device with the AlAs0.56Sb0.44 barrier exhibits 1.96 mS/μm peak transconductance and SS = 134 mV/dec at VDS = 0.5 V.