Improved programming and erasing speeds of poly-Si flash memory device by HfO_2/Si_3N_4 bandgap-engineered trapping layer

摘要

Effects of HfO_2/Si_3N_4 bandgap-engineered trapping layer (BETL) on poly-Si flash memory device are studied for the first time. Planar and nanowire (NW) channel flash memory devices are successfully fabricated to study the effects of BETL. The programming and erasing speeds can be improved by BETL on both planar and NW channel devices, and the improvement is more obvious on NW channel devices with even a lower operation voltage. The device with BETL and NW channel demonstrates the best programming and erasing speeds due to the electric-field enhancement effect and the band-engineering in charge-trapping layer. It also shows good retention and endurance properties, which makes it promising for 3-D memory integration.