Feasibility of InxGa1–xAs High Mobility Channel for 3-D NAND Memory

Epitaxial In
_x
Ga
_1–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
Ga
_1–x
As are thoroughly discussed; their impact on the electrical performances are investigated and the tunnel oxide (TuOx) quality is assessed. In
_x
Ga
_1–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 Cl
₂
. Thanks to the lower thermal budget involved, Cl
₂
seems the most suitable route to preserve the thickness of the TuOx. In
_x
Ga
_1–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.