First demonstration of sub-12 nm Lg gate last IGZO-TFTs with oxygen tunnel architecture for front gate devices

The first amorphous IGZO-based transistors integrated in a BEOL compatible gate-last integration scheme with buried oxygen tunnel under the channel and self-aligned contacts are demonstrated. This architecture reduces the number of critical process steps containing hydrogen and mitigates the R
series
increase during oxygen anneal for defect passivation. Higher I
on
is achieved without compromising on I
off
. We also report the shortest ever IGZO-TFTs with L
g
< 12 nm. Further, normally-off devices with I
on
> 6 µA/µm (without defect passivation anneal) were achieved through gate-oxide and IGZO thickness scaling.