Deposition temperature effect of the memory characteristics for Al₂O₃/Y₂O₃/SiO₂ (AYO) multi-stacked film

Abstract

An investigation was conducted involving the memory characteristics of the Pt/Al₂O₃/Y₂O₃/SiO₂/Si structure using a high-k Y₂O₃ charge trapping layer for SONOS (poly-silicon/oxide/nitride/oxide/silicon)-type nonvolatile memory applications. This work focused on Y₂O₃ layer deposition at different substrate temperatures, which ranged from 450–550°C by metal organic chemical vapor deposition (MOCVD) and examined the electrical properties and structural differences of each specimen. Results showed that the Y₂O₃ deposited at 500°C had the highest memory characteristics and reliability than the other deposition condition. The maximum memory window of capacitor with an Y₂O₃ trapping layer deposited at 500°C was 3.11 V which well endured up to 10⁴ program/erase (P/E) cycles. The results indicated that deposition temperature is one of the most critical factors influencing the charge trapping properties.