Fabrication of Gas-Sensor Chips Based on Silicon–Carbon Films Obtained by Electrochemical Deposition

Tatiana N Myasoedova,Mikhail N Grigoryev,Tatiana S Mikhailova,Nina K Plugotarenko

doi:10.3390/chemosensors7040052

Tatiana N Myasoedova, Mikhail N Grigoryev + Show 2 more

Open Access

https://doi.org/10.3390/chemosensors7040052

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Abstract

In this study, we designed two types of gas-sensor chips with silicon–carbon film, doped with CuO, as the sensitive layer. The first type of gas-sensor chip consists of an Al2O3 substrate with a conductive chromium sublayer of ~10 nm thickness and 200 Ω/□ surface resistance, deposited by magnetron sputtering. The second type was fabricated via the electrochemical deposition of a silicon–carbon film onto a dielectric substrate with copper electrodes formed by photoelectrochemical etching. The gas sensors are sensitive to the presence of CO and CH4 impurities in the air at operating temperatures above 150 °C, and demonstrated p- (type-1) and n-type (type-2) conductivity. The type-1 gas sensor showed fast response and recovery time but low sensitivity, while the type-2 sensor was characterized by high sensitivity but longer response and recovery time. The silicon–carbon films were characterized by the presence of the hexagonal 6H SiC polytype with the impurities of the rhombohedral 15 R SiC phase. XRD analysis revealed the presence of a CuO phase.

Highlights

The interest in solid-state gas sensors is due to their numerous advantages, like their small size, high sensitivity in detecting very low concentrations of a wide range of gaseous chemical compounds, the possibility of online operation, and, due to possible batch production, low cost [1,2]
We fabricated two types of gas sensors based on silicon-carbon films
The siliconcarbon films were electrochemically deposited via a two-stage technique onto an Al2 O3 substrate with a chromium sublayer and onto a dielectric substrate with copper electrodes with a special configuration

Summary

Introduction

The interest in solid-state gas sensors is due to their numerous advantages, like their small size, high sensitivity in detecting very low concentrations of a wide range of gaseous chemical compounds, the possibility of online operation, and, due to possible batch production, low cost [1,2]. Conductive diamond-like carbon (DLC) materials have attracted considerable attention as a gas sensor material for solid-state gas sensor applications [6,7], as they possess a unique combination of physical and chemical characteristics [8]. DLC materials poorly adhere to the substrate and function within a limited range of operating temperatures (

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