Structural and electrical characteristics of high-κ Er2O3 and Er2TiO5 gate dielectrics for a-IGZO thin-film transistors

• Published in: Nanoscale research letters Vol. 8; no. 1; p. 18
• Main Authors: Chen, Fa-Hsyang, Her, Jim-Long, Shao, Yu-Hsuan, Matsuda, Yasuhiro H, Pan, Tung-Ming
• Format: Journal Article
• Language: English
• Published: New York Springer New York 08.01.2013; BioMed Central Ltd; Springer
• Subjects: Chemistry and Materials Science; Materials Science; Molecular Medicine; Nano Express; Nanochemistry; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; Amorphous InGaZnO; TiO; Thin-film transistor; Er; O
• ISSN: 1931-7573; 1556-276X; 1556-276X
• DOI: 10.1186/1556-276X-8-18

In this letter, we investigated the structural and electrical characteristics of high- κ Er 2 O 3 and Er 2 TiO 5 gate dielectrics on the amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) devices. Compared with the Er 2 O 3 dielectric, the a-IGZO TFT device incorporating an Er 2 TiO 5 gate dielectric exhibited a low threshold voltage of 0.39 V, a high field-effect mobility of 8.8 cm 2 /Vs, a small subthreshold swing of 143 mV/decade, and a high I on / I off current ratio of 4.23 × 10 7 , presumably because of the reduction in the oxygen vacancies and the formation of the smooth surface roughness as a result of the incorporation of Ti into the Er 2 TiO 5 film. Furthermore, the reliability of voltage stress can be improved using an Er 2 TiO 5 gate dielectric.