A silicon crystalline resistor with an adsorbing porous layer as gas sensor

In this paper, a new integrated sensing device, that is a crystalline silicon resistor provided with an adsorbing porous silicon layer on its top, is proposed. The sensing mechanism is based on a gas-induced modulation effect of the resistor cross-section due to the adsorbed molecules in the porous film. The sensitivity of the device can be tuned by properly changing the polarization of a gate electrode. The working principle, the fabrication process and the electrical characterization of the device in presence of isopropanol vapors are presented and discussed.