Grain size monitoring of 3D flash memory channel poly-Si using multiwavelength Raman spectroscopy

Abstract

Raman spectroscopy was used for characterizing poly-Si after thermal annealing of chemical vapor deposited (CVD) thin a-Si films in the vertical channel region of 3D V-NAND device wafers using various annealing conditions and techniques. Raman spectra, indicating crystallization of a-Si films and grain growth of poly-Si with respect to annealing conditions and techniques, was measured using a multiwavelength Raman spectroscopy system.