Low temperature atomic layer deposited HfO₂ film for high performance charge trapping flash memory application

The impact of key process parameters on the electrical characteristics of atomic layer deposited HfO₂ films has been systematically studied with MHOS devices via capacitance–voltage (C–V) measurement. C–V hysteresis curves revealed that charge storage capacity is significantly enhanced with decreasing substrate temperature from 350 down to 150 °C and/or increasing purge time of the inert gas. The developed HfO₂ trapping layer was also demonstrated by a MAHOS memory device. Improved memory window, fast program speed and good retention characteristics have been obtained. The study provides a reference for memory performance improvement of HfO₂-based charge trap flash memory. (paper)