Metal-Assisted Solid-Phase Crystallization Process for Vertical Monocrystalline Si Channel in 3D Flash Memory

In order to improve the channel conductance of 3D flash memory cell, metal-assisted solid-phase single crystallization process has been demonstrated for the first time. Metal induced lateral crystallization (MILC) process is well-known for the thin film transistors (TFTs).We tried to apply this technology to channel Si in a vertical memory holes of 3D flash memory. Monocrystalline growth was confirmed by in- situ TEM and nano-beam diffraction (NBD) analysis. Moreover, it shows superior device characteristics (Icell, Vth, sub-threshold slope, transconductance) and those uniformities with maintaining memory performance and reliability.