Demonstration of genuine surface inversion for the p/n-In0.3Ga0.7Sb-Al2O3 MOS system with in situ H2 plasma cleaning

The results of an investigation into the impact of in situ H-2 plasma exposure on the electrical properties of the p/n-In-0.3 Ga-0.7 Sb-Al2O3 interface are presented. Samples were processed using a clustered inductively coupled plasma reactive ion etching and atomic layer deposition tool. Metal oxide semiconductor capacitors were fabricated subsequent to H-2 plasma processing and Al2O3 deposition, and the corresponding capacitance-voltage and conductance-voltage measurements were analyzed quantitatively via the simulation of an equivalent circuit model. Interface state (D-it) and border trap (N-bt) densities were extracted for samples subjected to the optimal process, with a minimum D-it of 1.73 x 10(12) eV(-1) cm(-2) located at similar to 110meV below the conduction band edge and peak N-bt approximately aligned with the valence and conduction band edges of 3 x 10(19) cm(-3) and 6.5 x 10(19) cm(-3), respectively. Analysis of the inversion response in terms of the extraction of the activation energy of minority carriers in inversion (p-type) and the observation of characteristics that pertain to minority carriers being supplied from an external inversion region (n-type) unequivocally demonstrate that the Fermi level is unpinned and that genuine surface inversion is observed for both doping polarities. Published under license by AIP Publishing.