Silicon nanowires based resistors as gas sensors

Abstract

International audienceSilicon nanowires (SiNWs) are synthesized following two methods: i) the VLS (Vapor-Liquid-Solid) growth technique (bottom up approach), and ii) the sidewall spacer fabrication (top down approach) commonly used in microelectronic industry. The VLS growth technique uses gold nanoparticles to activate the vapor deposition of the precursor gas and to initiate 100 nm diameter SiNWs network growth. In the case of the sidewall spacer method, a polysilicon layer is deposited by LPCVD (Low Pressure Chemical Vapor Deposition) technique on SiO2 wall patterned by conventional UV lithography technique. Polysilicon film is then plasma etched. Accurate control of the etching rate leads to the formation of spacers with a 100 nm curvature radius that can be used as polysilicon NWs. Each kind of nanowires is integrated into resistors fabrication. Electrical measurements show the potential use of these SiNWs based resistors as gas sensors for ammonia (NH3) and smoke detection

Bacteria electrical detection using 3D silicon nanowires based resistor

“…(b)). The potential use as high sensitive gas (ammonia) sensors of such SiNWs based resistors was previously reported [22]. Escherichia coli ATCC 35218 bacteria deposition was carried out from serial dilutions in sterile distilled water of an overnight bacterial culture in trypticase soy broth (BBL Trypticase Soy Broth, Becton Dickinson®) incubated at 37°C.…”

Dual Gate Microsensors and Nanomaterials for Chemical Detection

“…For this purpose, silicon nanowires were first considered. In Figure 4 is presented a typical SEM image of the active surface of the device after integration of the silicon nanowires using a VLS (Vapor Liquid Solid) process [6]. The electrical characteristics of the device presented in Figure 4b validate the compatibility of silicon nanowires with FET structure.…”

Submicron Wire Fabrication on Silicon Substrate Based on Atomic Force Microscopy Technique

“…In addition, the fabricated device shows relative sensitivity of 35 % to the oxygen gas at room temperature. The percentage of absolute relative sensitivity, S, is defined as (1), where, Iₒ and I correspond to current obtained before and after gas exposure, respectively [8]- [9].…”