Feasibility of In<italic>x</italic>Ga1–<italic>x</italic>As High Mobility Channel for 3-D NAND Memory

Abstract

Epitaxial In x Ga1– x As is grown by metal organic vapor phase epitaxy as replacement of polycrystalline silicon (Si) channel for high-density 3-D NAND memory applications. The most challenging steps to integrate In x Ga1– x As are thoroughly discussed; their impact on the electrical performances are investigated and the tunnel oxide (TuOx) quality is assessed. In x Ga1– x As channels with a diameter down to ~45 nm and different In concentrations are obtained after using two alternative surface preparation routes: HCl and Cl2. Thanks to the lower thermal budget involved, Cl2 seems the most suitable route to preserve the thickness of the TuOx. In x Ga1– x As channels with In concentration, x, higher than 0.45 have superior conduction properties compared with poly-Si channel, showing higher $I_{\mathrm { {on}}}$ and transconductance.