Thermally stable Ni-silicide gate electrode with TiN barrier metal for NAND flash memory application with 24 nm technology and beyond

Abstract

Ni-silicide with TiN barrier metal has been demonstrated for NAND flash memory devices with 24 nm technology node as a gate word line. When a TiN layer with 200 Å thickness by physical vapor deposition (PVD) is inserted in the control gate polysilicon, inter-diffusion of Ni and grain growth of NiSi are successfully suppressed. As results, no significant sheet resistance increase is observed even at the narrow gate line with 24nm width and its thermal stability is maintained up to 900 ℃.

Low-Resistivity Titanium Nitride Thin Films Fabricated by Atomic Layer Deposition with TiCl4 and Metal–Organic Precursors in Horizontal Vias

“…In semiconductors, TiN thin films that are conducting are utilized for several applications, including diffusion barrier liners for W, Co, and Cu, − barrier metals for high-density NAND flash memory devices, and other 3D structures (especially re-entrant undercut structures) in which a metal diffusion barrier is needed, such as 3D NAND, 3D DRAM, gate all around (GAA) channels, and Si nanowire gate stacks . TiN can also be utilized as a surface layer on carbon nanotubes in supercapacitors .…”