Enhanced ZnO Thin-Film Transistor Performance Using Bilayer Gate Dielectrics

Abstract
We report ZnO TFTs using Al2O3/Ta2O5 bilayer gate dielectrics grown by atomic layer deposition. The saturation mobility of single layer Ta2O5 dielectric TFT was 0.1 cm2 V-1 s-1, but increased to 13.3 cm2 V-1 s-1 using Al2O3/Ta2O5 bilayer dielectric with significantly lower leakage current and hysteresis. We show that point defects present in ZnO film, particularly VZn, are the main reason for the poor TFT performance with single layer dielectric, although interfacial roughness scattering effects cannot be ruled out. Our approach combines the high dielectric constant of Ta2O5 and the excellent Al2O3/ZnO interface quality, resulting in improved device performance. © 2016 American Chemical Society.

Citation
Alshammari FH, Nayak PK, Wang Z, Alshareef HN (2016) Enhanced ZnO Thin-Film Transistor Performance Using Bilayer Gate Dielectrics. ACS Applied Materials & Interfaces 8: 22751–22755. Available: http://dx.doi.org/10.1021/acsami.6b06498.

Acknowledgements
Research reported in this publication was supported by King Abdullah University of Science and Technology (KAUST). The authors thank the staff of the Nanofabrication Facility and imaging and characterization at KAUST, particularly Ahad Syed and Nimer Wehbe, for their excellent support.

Publisher
American Chemical Society (ACS)

Journal
ACS Applied Materials & Interfaces

DOI
10.1021/acsami.6b06498

PubMed ID
27553091

Additional Links
http://pubs.acs.org/doi/full/10.1021/acsami.6b06498

Permanent link to this record