Home > Research > Publications & Outputs > Structure and properties of solution processed ...
View graph of relations

Structure and properties of solution processed hafnium oxide gate dielectrics for their applications in high mobility ZnO based thin film transistors

Research output: Contribution to conference - Without ISBN/ISSN Speech

Published
Publication date2014
<mark>Original language</mark>English
EventEMRS 2014, Spring Meeting - France, Lille, France
Duration: 26/05/201430/05/2014

Conference

ConferenceEMRS 2014, Spring Meeting
Country/TerritoryFrance
CityLille
Period26/05/1430/05/14

Abstract

In recent years a wide variety of soluble precursors have been investigated as potential alternatives for the fabrication of oxide-based TFTs using large area deposition methods including spin casting, dip coating and spray pyrolysis. The ever increasing demand for high performance thin film transistors based on metal oxide channels has given a boost to the development of alternatives to SiO2 gate dielectrics with desirable characteristics in terms of thermal stability, band offset, interface quality and ability to control the FET’s gate threshold voltage. Among these, ZrO2, HfO2, Y2O3 and Al2O3 are the most studied dielectrics and are widely considered to be excellent candidates because of their high dielectric constants, good thermal stability and large band gaps. This work reports on the structure and properties of spray pyrolysis-grown HfO2 thin films and their implementation in ZnO-based TFTs. The HfO2 films were found to be of monoclinic crystal structure with a band gap of 5.7 eV, dielectric constant as high as 19, very low leakage currents and dielectric breakdown in excess of 2.7 MV/cm. The related ZnO based TFTs exhibit excellent electron transport characteristics with negligible hysteresis, operating voltages in the range between 5-6 V, high electron mobility on the order of 40 cm2 V−1 s−1 and high current on/off ratio of about 10^7.