In this study, we investigated the effect of various SiO2 tunnel layers on the characteristics of charge trap memories with Metal/SiO 2/Si3N4/SiO2/n-type poly-Si (MONOS) structures. For MONOS devices, SiO2 tunnel layers were formed on poly-Si channels using thermal oxidation, radical oxidation, and LP-CVD. We investigated the characteristics of each SiO2 tunnel layer on poly-Si including breakdown, leakage current and FN tunneling. Radical SiO2 and LP-TEOS SiO2 showed larger breakdown voltages with more uniform thickness than thermal SiO2 on poly-Si channels. MONOS devices with radical SiO2 and LP-TEOS SiO2 tunnel layers showed improved program/erase (P/E) and endurance compared with thermal SiO 2. In particular, the MONOS device with LP-TEOS SiO2 showed the largest memory window with the fastest P/E operation, which was attributed to enhanced defect-assisted tunneling in LP-TEOS SiO2. The endurances of MONOS devices were measured and related to the flat-band voltage shift in conjunction with trapped charge types in SiO2 tunnel dielectrics.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering