Memory effect of Al-rich AlN films synthesized with rf magnetron sputtering

Al-rich AlN thin film, which is deposited onto n-type Si substrate by radio frequency sputtering of Al target in an argon and N2 gas mixture, can exhibit a large memory effect as a result of charge trapping in the Al nanoparticles/nanoclusters embedded in the AlN matrix. For the metal-insulator-semiconductor structure with a 60 nm Al-rich AlN thin film, a voltage of -15 V applied to the metal electrode for 10-6 s causes a flatband voltage shift of ∼1.5 V. Both electron trapping and hole trapping are possible, depending on the polarity of the applied voltage. In addition, whether the electron trapping or the hole trapping is the dominant process also depends on the charging time and the magnitude of the voltage. The Al-rich AlN thin films provide the possibility of memory applications with low cost