Non-Ideal Behaviour of SiO₂ Passivated Ni-(n)GaAs Schottky Barrier Diodes

Abstract

The non-ideal I vs V and 1/C² vs V plots of Si0₂ passivated Ni-(n) GaAs Schottky barrier diodes are primarily due to formation of an interfacial layer at the metal-semiconductor interface during Ni Evaporation and due to excess capacitance of the MOS structure appearing parallel to the junction capacitance, respectively. The ideality factor, η, of the diodes is found to lie between 1.07 and 1.13 irrespective of the structural variations inclusive of SiO² passivation. The effect of impurity gradation in the active GaAs epitaxial layer of C-V characteristics is also discussed.