Influence of Ti substitution on the electrical properties of metal-ferroelectric (BiFeO3)-insulator (HfO2)-silicon structures for nonvolatile memory applications

Abstract

Articles you may be interested inFabrication and characterization of metal-ferroelectric ( PbZr 0.6 Ti 0.4 O 3 ) -insulator ( La 2 O 3 )semiconductor capacitors for nonvolatile memory applications Influence of Ar ∕ O 2 ratio on the electrical properties of metal-ferroelectric ( Bi Fe O 3 ) -insulator ( Hf O 2 )semiconductor capacitors fabricated by rf magnetron sputtering Fabrication and characterization of metal-ferroelectric ( Pb Zr 0.53 Ti 0.47 O 3 ) -Insulator ( Y 2 O 3 )semiconductor field effect transistors for nonvolatile memory applications Characterization of metal-ferroelectric ( Bi Fe O 3 ) -insulator ( Zr O 2 ) -silicon capacitors for nonvolatile memory applications Appl. The charge trapping effect of metal-ferroelectric ( Pb Zr 0.53 Ti 0.47 O 3 ) -insulator ( Hf O 2 ) -silicon capacitors J. Appl. Phys. 98, 044103 (2005);Metal-ferroelectric (Ti-substituted BiFeO 3 )-insulator (HfO 2 )-semiconductor structures have been fabricated via the cosputtering technique. Ti 4þ substitution at the Fe site was investigated through x-ray photoelectron spectra and x-ray diffraction patterns at postannealing temperatures of 500 to 700 C. The capacitance-voltage memory windows as functions of the insulator film thickness and the dc power for Ti were measured and compared. A memory window of 3.1 V was obtained at a sweep voltage of 8 V under O 2 -rich conditions. The leakage current and the charge injection effect, especially gate injection, can be greatly improved by Ti substitution. The effects of the postannealing temperature and the substitution amount on the leakage current can be well explained by the defect reaction model.