Optical capacitance-voltage characterization of charge traps in the trapping nitride layer of charge trapped flash memory devices

Abstract

Extracting the trap distribution in charge trapping layers of charge trap flash memory devices, an optical C-V method (OCVM) is proposed. Applying photons with λ=532 nm to the oxide-nitride-oxide layer with 506023 Å in metal-oxide-nitride-oxide-semiconductor charge trap flash devices, the trap density in the charge trapping nitride layer is extracted to be 1.16× 1018 -1.67× 1019 cm-3 eV-1 over the energy EC - Et =1.36-1.64 eV. Combining sub-band-gap photons in C-V characterization, the OCVM method is free from the thermal and electrical stresses which are inherent in conventional characterization methods even though they are critical error factors for accurate characterization of charge trapped flash memory devices. © 2007 American Institute of Physics.