Alcohol-based Digital Etch for Sub-10 nm Diameter III-V Vertical Nanowire Transistors
Research Report Highlight
Novel alcohol-based digital etch has been successfully applied to InGaSb-based heterostructures, the first demonstration. Vertical InGaAs nanowire gate-all-around MOSFETs are also reported.
This work introduces a novel alcohol-based digital etch technique for III-V vertical nanowire MOSFET fabrication. The new technique addresses the limitations of the conventional water-based approach in enabling structures with sub-10 nm 3D features. Using the same oxidation step, the new technique shows an etch rate of 1 nm/cycle, identical to the conventional approach. Sub-10 nm fins and vertical nanowires with a high yield and mechanical stability have been achieved. InGaAs nanowires with diameter of 5 nm and an aspect ratio > 40 have been demonstrated. The new technique has also been successfully applied to InGaSb-based heterostructures. This is the first demonstration of digital etch in this material system. Vertical InGaAs nanowire gate-all-around MOSFETs with a subthreshold swing of 70 mV/dec at VDS = 50 mV have been obtained at a nanowire diameter of 40 nm, demonstrating the good interfacial quality that the new technique provides.