Characteristics of chemically-synthesized (CS) gold nanoparticle (Au-NP) nonvolatile memories (NVMs) with low-damage NH3 plasma treatment on a tunneling oxide (TO) layer have been investigated. Although the dot density of CS Au-NPs is decreased, the programming efficiency of memories with optimized NH3 plasma treatment condition is enhanced due to the formation of a trapezoid-like energy band diagram of the TO layer by nitrogen incorporation. With the extraction of relative permittivity and electron affinity of the TO layer, the capacitance-voltage (C-V) and programming behaviors of CS Au-NP memories with low-damage NH3 plasma treatment on the TO layer are well-fitted by the TCAD (Technology Computer-Aided-Design) simulation. Further, the built-in electric field induced by the trapezoid-like energy band diagram of the TO layer can suppress the leakage current of the TO layer, thereby improving the data retention properties. The low-damage NH3 plasma treatment that results in no plasma damage to the TO layer has been proposed to be the probable candidate for future NVM applications. (C) 2016 Elsevier B.V. All rights reserved.