Improvement on programming and erasing speeds for charge-trapping flash memory device with SiGe buried channel

Abstract

SiGe buried channel with different Ge contents and various thicknesses of Si-cap layer on operating characteristics of charge-trapping (CT) flash devices were studied in this work. The results show that the programming and erasing speeds of CT flash devices are significantly improved by employing SiGe buried channel. Enhancement up to merely 20 times on programming speed was achieved. The retention characteristics of flash devices are satisfactory with suitable Ge content in SiGe buried channel and thickness of Si-cap layer. From the measurement of secondary ion mass spectroscopy, the operation characteristics of flash devices with SiGe channel were sensitive to the distribution of Ge atoms.