Tailoring optical and electrical properties of MgO thin films by 1.5 MeV H~+ implantation to fluences

摘要

Thin films of magnesia (MgO) with (1 00) dominant orientations were implanted with 1.5 MeV H ' ions at room temperature to various fluences of 10~(13), 10~(14) and 10~(15) ions/cm~2. X-ray analysis unambiguously showed crystallinity even after a peak damage fluence of 10~(15) ions/cm~2. Rutherford backscattering spectrometry combined with ion channeling (RBS/C) was used to analyze radiation damages and defect distributions. Optical absorption band observed at 5.7 eV in implanted films was assigned to the anion vacancies and the defect was completely disappeared on annealing at 450 ℃. Number of F-type defects estimated was 9.42 × 10~(15)cm~(-2) for the film implanted with 10~(15) ions/cm~2. DC electrical conductivity of 4.02 × 10~(4) S cm~(1) was observed in the implanted region which was three orders higher than the as-deposited films. In unison, film surface was modified as a result of the formation of aggregates caused by the atomic mixing of native matrix atoms (Mg and O) and precipitated hydrogen.