A micro-scale hot-surface device based on non-radiative carrier recombination [gas sensor example application]

This work employs the idea of making micro-scale hot-surface devices (e.g. sensors, flow meters, micro reactors, etc) based on generation of heat due to nonradiative recombination of carriers in a thin (13 nm) poly silicon surface layer. An important part of the device is a nano-scale (10-100 nm) conductive link created between two polysilicon electrodes separated by a dielectric (a capacitor-like structure). Using this approach, we designed and realized a new silicon device with the hot surface reduced to a sub-μm-size area, operating at very low power down to sub-μW. From the experiments, such a device can be used as a heat source as well as a sensitive detector of heat. In this paper, we describe the thermo-electrical properties of fabricated devices and demonstrate their feasibility to perform as gas- adsorption- desorption sensors operating at extremely low power consumption.