Memory characteristics and tunneling mechanism of Pt nano-crystals embedded in HfAlOx films for nonvolatile flash memory devices

A non-volatile flash memory device based on metal oxide semiconductor (MOS) capacitor structure has been fabricated using platinum nano-crystals(Pt–NCs) as storage units embedded in HfAlOx high-k tunneling layers. Its memory characteristics and tunneling mechanism are characterized by capacitance–voltage(C–V) and flat-band voltage-time(ΔVFB-T) measurements. A 6.5V flat-band voltage (memory window) corresponding to the stored charge density of 2.29 × 1013cm−2 and about 88% stored electron reserved after apply ±8V program or erase voltage for 105s at high frequency of 1 MHz was demonstrated. Investigation of leakage current–voltage(J–V) indicated that defects-enhanced Pool-Frenkel tunneling plays an important role in the tunneling mechanism for the storage charges. Hence, the Pt–NCs and HfAlOx based MOS structure has a promising application in non-volatile flash memory devices. •The Pt nano-crystals and based-HfAlO films memory devices was fabricated.•The 6.5 V memory window and 88% stored charge after 105 s were detected.•The defects-enhanced Pool-Frenkel tunnel may dominate the stored charge action.