Electrical characteristics enhancement of Au/n-GaAs Schottky barrier diode using sulfur passivation of GaAs surface by (NH4)2SX sulfurization technique

In this study, sulfur-passivation of GaAs surface is used to fabricate free interface state densities in Au/n-GaAs Schottky barrier diodes (SBDs). The effect of passivation on Schottky diode parameters such as ideality factor (n), Schottky barrier height (φ
_B0
) and reverse saturated current (Is) were investigated by the current-voltage (I-V) characteristic. The results indicate that the Schottky barrier height ((φ
_B0
) and the reverse saturated current (Is) are increased by 0.136 eV and about two orders of magnitude respectively, whereas the ideality factor is decreased by 0.52 for (NH
₄
)
₂
S
_X
passivated sample. This is attributed to a decrement of interfacial states and prevention of Fermi level pinning. Also, the current-voltage (I-V) characteristics of Au/n-GaAs Schottky diode were measured in a temperature range of 300-400K, in order to investigate the temperature dependence of the ideality factor (n), the Schottky barrier height (φ
_B0
) and the reverse saturated current (Is).