Structural and Electrical Properties of HfO2/n-InxGa1-xAs structures (x: 0, 0.15, 0.3 and 0.53)

Abstract

In this work results are presented of an investigation into the structural and electrical properties of HfO2 films on GaAs and InxGa1-xAs substrates for x: 0.15, 0.30, and 0.53. The capacitance-voltage responses of the GaAs and InxGa1-xAs (x: 0.15 and 0.30) are dominated by an interface defect response. Analysis of these samples at 77K indicates that the defect density is > 2.5x10(13) cm(-2). For the HfO2/In0.53Ga0.47As system, 77K capacitance-voltage responses indicate surface accumulation is achieved. The results are consistent with a high defect density, with an energy level >= 0.75 eV above the valence band in the HfO2/InxGa1-xAs system, where the defect energy with respect to the valence band, does not change with the composition of the InxGa1-xAs. The HfO2/In0.53Ga0.47As interface exhibits two defects at 0.3eV (1.7x10(13)cm(-2)eV) and 0.61eV (1.5x10(13)cm(-2)eV) above the valance band edge. The defect at 0.61eV is removed by forming gas annealing at 325 degrees C.