Defect-related electroluminescence from metal-oxide-semiconductor devices with ZrO_2 films on silicon

摘要

Defect-related electroluminescence (EL) from ZrO_2 films annealed under different atmosphere has been realized by means of electrical pumping scheme of metal-oxide-semiconductor (MOS) devices. At the same injection current, the acquired EL from the MOS device with the vacuum-annealed ZrO_2 film is much stronger than that from the counterpart with the oxygen-annealed ZrO_2 film. This is because the vacuum-annealed ZrO_2 film contains more oxygen vacancies and Zr~(3+) ions. Analysis on the current-voltage characteristic of the ZrO_2-based MOS devices indicates the P-F conduction mechanism dominates the electron transportation at the EL-enabling voltages under forward bias. It is tentatively proposed that the recombination of the electrons trapped in multiple oxygen-vacancy-related states with the holes in the defect level pertaining to Zr~(3+) ions brings about the EL emissions.