Abstract
Electrical characteristics of charge trapping-type flash devices with HfAlO charge trapping layer nitrided by plasma immersion ion implantation (PIII) technique with different implantation energies and time are studied. Utilizing Fowler-Nordheim (FN) operation, the programming speed of flash memory with charge trapping layer nitrided at low implantation energy is faster than that of control sample. The erasing speed of PIII-treated sample is slightly slower than that of control one, which might be due to the formation of silicon nitride in the tunneling oxide. The retention characteristics of all PIII-treated samples are significantly improved. Different peak locations of implanted nitrogen concentrations are formed by different implantation energies, which cause various electrical characteristics of flash devices. © 2009 Elsevier B.V. All rights reserved.