III–V gate stack interface improvement to enable high mobility 11nm node CMOS

We report significant improvements in the high-k/In
_0.53
Ga
_0.47
As interface quality by controlling atomic layer deposition (ALD) oxidizer chemistry. A step-by-step correlation between electrical data and chemical reactions at the high-k/InGaAs interface has been established using synchrotron photoemission. AsO
_x
, GaO
_x
, and In
₂
O
₃
formed during unintentional ALD surface oxidation and the increase of As-As bonds are responsible for degrading device quality. A better quality H
₂
O-based high-k gate stack is evidenced by less capacitance-voltage (CV) dispersion (14% in ZrO
₂
), smaller CV hysteresis (37% in Al
₂
O
₃
and 47% in ZrO
₂
), fewer border traps (Q
_br
) (96% in Al
₂
O
₃
and 25% in ZrO
₂
), and lower mean interface traps density (D
_it
) (91% in Al
₂
O
₃
and 29% in ZrO
₂
). Improvements in I
_d
and G
_m
therefore have been achieved by replacing O
₃
with H
₂
O oxidizer. Our work suggests that H
₂
O-based high-k is more promising than O
₃
-based high-k. These results positively impact the industry's progress toward III-V CMOS at the 11nm node.