Sulfur cleaning for (100), (111)A, and (111)B InGaAs surfaces with In content of 0.53 and 0.70 and their Al2O3/InGaAs MOS interface properties

We have studied the impact of sulfur cleaning for (100), (111)A, and (111)B InGaAs surfaces with In content of 0.53 and 0.70 and their Al
₂
O
₃
/InGaAs MOS interfaces using an (NH
₄
)
₂
S
_x
solution. We found that the sulfur cleaning can effectively remove native oxides from InGaAs surfaces and passivate the InGaAs surfaces by sulfur atoms. Combining with trivalent oxide passivation using Al
₂
O
₃
, the Al
₂
O
₃
/InGaAs MOS interfaces with sulfur cleaning can realize good interface properties with the small frequency dispersion of the capacitance versus voltage (C - V) curves in accumulation region with independent of In content and the surface orientations.