Table 2: Summary of viable technical solutions to mitigate device characteristic issues of charge storage NVM.

Categories of mitigation techniquesMitigation techniquesPurposesReferences

Tunnel barrier engineeringTunnel oxide top/bottom nitridationTo enhance endurance and retention performance of tunnel oxide of flash memory[6782]
VARIable Oxide Thickness (VARIOT)To implement multilayer dielectric stacks with combination of high-k and low-k dielectrics to enhance either endurance speed or retention performance[6063]
Implementation of high-k dielectrics To replace interpoly ONO dielectric stack of standard FG flash memory or tunnel oxide of CTF with high-k dielectrics to enhance reliability performance, for example, HfO2, Al2O3, and HfAlO[64, 65]

Novel flash cell structureHemi-Cylindrical FET (HCFET)To reduce severe short channel effect of small dimension beyond sub-40 nm as compared to planar standard FG flash[4, 15]
FinFETOffer better scalability and better short channel effect as compared to planar structure of standard FG flash [1619]

Emerging NVM technologiesPhase change memory (PCM) Utilizes electrical properties of chalcogenide based material to store data. Offers better scalability than standard FG flash with program/erase and retention performance rivals standard FG flash[2137]
Magnetoresistive random access memory (MRAM)Utilizes the resistance change of Magnetic Tunnel Junction (MTJ) to store data which is determined by the magnetic directions of two electrodes made of ferromagnetic material. [6]
NanocrystalUtilizes mutually isolated quantum dots as charge storage node in control oxide layer to replace conductive FG for further dimension scaling[3859, 81, 82]
Resistive RAM (RRAM)Relies on the ability to switch to different resistance states by applying sufficient voltage across the structures. RRAM consists of simple oxide or complex oxide or transition metal oxide structures[6, 66, 110]