Quantum Well InAs/AlSb/GaSb Vertical Tunnel FET With HSQ Mechanical Support

A type-III (broken gap) band alignment heterojunction vertical in-line InAs/AlSb/GaSb tunnel FET, including a 2-nm-thin AlSb tunneling barrier is demonstrated. The impact of overlap and underlap gate is studied experimentally and supported further by quasi-stationary 2-D TCAD Sentaurus device simulations. Hydrogen silsesquioxane is used as a novel mechanical support structure to suspend the 10-nm-thin InAs drain with enough undercut to be able to demonstrate an overlap gate architecture. The overlap gate InAs/AlSb/GaSb TFET shows an ON current density of 22 μA/μm
²
at
$V_{{\rm GS}} = V_{{\rm DS}} = 0.4$
V and the subthreshold slope is 194 mV/decade at room temperature and 46 mV/decade at 100 K.