Effect of annealing atmosphere on characteristics of MONOS with LaTiON or HfLaON as charge storage layer

Abstract

Charge-trapping memory capacitor with LaTiON or HfLaON serving as charge storage layer is fabricated by reactive sputtering method, and influences of post-deposition annealing (PDA) in NH3 or N2 ambient on its memory characteristics are investigated. It is found that before PDA, the LaTiON sample exhibits better retention characteristic than the HfLaON sample, but the later shows larger memory window (4.8 V at +/-12 V/1 s), and after PDA, the NH3-annealed sample has faster program/erase speed, better retention and endurance properties than the N2-annealed sample, owing to nitridation role of NH3. Furthermore, the HfLaON sample with PDA in NH3achieves a large memory window of 3.8 V at +/-12 V/1 s, and also shows better retention and endurance properties than the LaTiON sample with PDA in NH3.