Investigations on the CdS passivated anodic oxide–InP interface for MOS structures

Thin layers of cadmium sulfide have been deposited on 〈111〉 n-InP using the chemical bath deposition technique at room temperature. X-ray photoelectron spectroscopy (XPS) results show that sulfur in CdS removes native oxide present on the InP surface and forms a chemically stable surface. Anodic oxidation was carried out on the CdS passivated InP surface. XPS results of oxides show the formation of highly stable P2O5. Improved C–V characteristics have been observed on CdS treated MOS diodes. Delay time measurements and bias stress measurements demonstrate the high stability of CdS passivated MOS diodes. NSS values as low as 3×1010 cm−2 eV−1 were obtained for CdS treated MOS diodes.