Conductometric sensors based on InGaAs/GaAs nanocoils

We present the use of integrated semiconductor nanocoils for conductometric sensors. The three-dimensional structures are made of an n-type InGaAs/GaAs bilayer. They are suspended over the chip surface and connected to one electrode on each side. The process is based on conventional batch microfabrication techniques. Process and design features that are critical for the realization of this type of device are described. High sensor performance can be achieved due to the high surface-to-volume ratio of the helical nanostructures. The use of these structures for temperature sensors and for photoconductive detectors is demonstrated.