Influences of thermal annealing, the electrolyte pH, and current density on the interface state density distribution of anodic MOS structures

Saglam M., Türüt A., NUHOĞLU Ç., Efeoğlu H., Kılıçoğlu T., Ebeoğlu M.

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, vol.65, no.1, pp.33-37, 1997 (SCI-Expanded) identifier identifier


An investigation of the effect of thermal annealing and anodization parameters, such as the electrolyte pH and current density, on capacitance-voltage and interface state density distribution characteristics has been made. Al(anodic oxide) SiO2/p-Si MOS structures were prepared: in 0.1 M K2SO4 electrolyte with a pH of 7 (the 0.1 M KOH solution was buffered with H2SO4) at current densities of 3, 5, and 7 mA/cm(2) and with four different pH; values of the electrolyte at 3 mA/cm(2). It is found that thermal annealing a relatively low temperature can be used to improve the anodic MOS characteristics. Moreover, of the pH and current density it followed that the pH has a dominant role in the interface electrical properties. The lowest interface state densities at the maximum and the midgap positions are 7.1 x 10(11) and 2.7 x 10(10) eV(-1) cm(-2) for a sample made with pH = 7, J = 3 mA/cm(2). The characteristics of this sample seem satisfactory for device applications of anodized p-Si.