Formation of dual-phase HfO2-Hf(sub x)Si(sub 1-x)O2 dielectric and its application in memory devices

The phase-separation phenomenon of Hf0.5Si0.5O2 film deposited on SiO2 or sandwiched by SiO2 is studied by x-ray photoelectron spectroscopy and transmission electron microscopy. The analysis reveals that for a given electric field applied to the tunnel oxide, the programming speed of memory devices using a dual-phase HfO2-Hf(sub x)Si(sub 1-x)O2 (DPHSO) or HfO2 film as a trapping layer is faster than that using Si3N4.