The Schottky characteristics of Ti/n-GaAs surface-treated by N2 plasma

The Schottky characteristics of Ti contacts on n-GaAs surface-treated by N₂ plasma at different temperature are studied. The capacitance-voltage (C-V) characteristic of the samples surface-treated by N₂ plasma is far more ideal than that of the pure GaAs samples. The Schottky characteristic of the samples surface-treated at 350°C is better than that of samples treated at 950°C. In this article, the zero-bias Schottky barrier height (SBH) Φ_b0, the flat-band SBH Φ_b⁰, the thickness of the interfacial layer δ, the permittivity of the interfacial layer ε_i and the ideality factor n of the samples at different nitridation temperature are extracted from the forward, reverse current-voltage (I-V) and the C-V measurement, respectively. Also the distribution of interface states density is qualitatively determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height.