Optimization of RF sputtering process parameters on electrical resistivity, deposition rate and sensitivity of Al-doped ZnO thin films grown on Si substrate using grey-Taguchi technique

Bulletin of Materials Science

M VANMATHI^1¹  M MOHAMED ISMAIL^1² 

[1]School of Electrical and Communication Sciences, B S Abdur Rahman Crescent Institute of Science and Technology, Chennai 600048, India^1

[2]School of Mechanical and Building Sciences, Vellore Institute of Technology, Chennai 600127, India^2

关键词: Al-doped ZnO;    thin films;    resistivity;    deposition rate;    sensitivity.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Increasing environmental pollution globally demands gas sensors for monitoring urban air quality, fire and exhaust from automobiles. The need for high performance gas sensors requires a good control over sensing material structure. This paper studies the suitability of Al-doped ZnO thin films for development of CO gas sensors. Deposition of Al-doped ZnO thin films on Si substrates by the radio frequency sputtering technique was carried out to study the influence of process parameters. The process parameters selected for the analysis were power, deposition time, substrate temperature and working pressure. An orthogonal array L16 (4$^4$), signal-to-noise ratio and analysis of variance (ANOVA) were performed to optimize the electrical resistivity, deposition rate and sensitivity of the thin films using the Taguchi method. Grey relational grade (GRG) was performed to obtain multiple-performance characteristics of the thin films by optimizing the process parameters. GRG analyses identified the process parameters: power 150 W, deposition time 35 min, substrate temperature 25$^{\circ}$C and working pressure 1.5 Pa showed optimal multiple-performance characteristics. ANOVA analyses indicate that power and substrate temperature show significant effect compared with other parameters. Thin films at the annealingtemperature (450$^{\circ}$C) showed a decrease in electrical resistivity and an increase in sensitivity. At the sensor operatingtemperature of 150$^{\circ}$C, Al-doped thin films exhibited the lowest resistivity $3.76 \times 10^{−3}$ $\Omega$-cm and the highest sensitivity of 59%. The optimal multiple-performance characteristic of thin film sample identified is found suitable for CO gas-sensing applications.

【 授权许可】

CC BY