High-k dielectrics on (100) and (110) n-InAs: Physical and electrical characterizations.

Two high-k dielectric materials (Al₂O₃ and HfO₂) were deposited on n-type (100) and (110) InAs surface orientations to investigate physical properties of the oxide/ semiconductor interfaces and the interface trap density (D_it). X-ray photoelectron spectroscopy analyses (XPS) for native oxides of (100) and (110) as-grown n-InAs epi wafers show an increase in As-oxide on the (100) surface and an increase in InOx on the (110) surface. In addition, XPS analyses of high-k (Al₂O₃ and HfO₂) on n-InAs epi show that the intrinsic native oxide difference between (100) and (110) epi surfaces were eliminated by applying conventional in-situ pre-treatment (TriMethyAluminium (TMA)) before the high-k deposition. The capacitance-voltage (C-V) characterization of HfO₂ and Al₂O₃ MOSCAPs on both types of n-InAs surfaces shows very similar C-V curves. The interface trap density (Dit) profiles show Dit minima of 6.1 × 10¹²/6.5 × 10₁₂ and 6.6 × 10¹²/7.3 × 10¹² cm^-2 eV-1 for Al₂O₃ and HfO₂, respectively for (100) and (110) InAs surfaces. The similar interface trap density (Dit) on (100) and (110) surface orientation were observed, which is beneficial to future InAs FinFET device with both (100) and (110) surface channel orientations present. [ABSTRACT FROM AUTHOR]