Coordination number modification at Al2O3/InP interfaces using sulfur and nitride passivations

By focusing on the Al/Al
₂
O
₃
/InP capacitor structure, impacts on coordination number modification using sulfur and nitride passivations against traps and charge formation are investigated. Improved electrical characteristics with low leakage current density, hysteresis, interface trap density and capacitance frequency dispersion are demonstrated after sulfur or nitride interface passivations. It is clarified that sulfur interface passivation is more effective in reducing the interface traps while nitride interface passivation shows stronger impact in suppressing the generation of bulk and border traps and the negative interface charges. A possible model based on coordination number is proposed to explain the mechanism of the different trap and charge behaviors for sulfur and nitride interface passivations.