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

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 lambda=532 nm to the oxide-nitride-oxide layer with 50/60/23 angstrom in metal-oxide-nitride-oxide-semiconductor charge trap flash devices, the trap density in the charge trapping nitride layer is extracted to be 1.16x10(18)-1.67x10(19) cm(-3) eV(-1) over the energy E-C-E-t=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. (C) 2007 American Institute of Physics.