In this work we present sputtered multicomponent dielectrics based on mixtures of HfO₂ and SiO₂. This way it is possible to get stable amorphous structure up to 800ºC, that does not happen for pure HfO₂, for instance, that present a polycrystalline structure when deposited without any intentional substrate heating. Besides, also the band gap of the resulting films is increased when compared with pure HfO2 that theoretically is an advantage in getting a suitable band offset with the semiconductor layer on oxide TFTs. Concerning the electrical characterization, the leakage current on c-Si MIS structures is low as 10^-9 Acm^-2 at 10 V. The amorphous structure of the films also lead to better dielectric/semiconductor interfaces, as suggested by C-V characteristics on GIZO MIS structures, which do not present strong variation with frequency. On other hand, the dielectric constant decreases due to the incorporation of SiO₂ and Al₂O₃. Further improvement on insulating and interface characteristics is achieved using multilayer stacks and substrate bias during deposition.

Date Published: 1 March 2012
PDF: 16 pages
Proc. SPIE 8263, Oxide-based Materials and Devices III, 826316 (1 March 2012); doi: 10.1117/12.909454

Published in SPIE Proceedings Vol. 8263:
Oxide-based Materials and Devices III
Ferechteh H. Teherani; David C. Look; David J. Rogers, Editor(s)