Reduction in interface state density of SiO₂/Si-IPL/InP by fluorine and sulfur passivations

Abstract

The characteristics of a liquid-phase-deposited SiO 2 film on InP were investigated. The mixture of H 2 SiF 6 and H 3 BO 3 aqueous precursors was used as the growth solution. SiO 2 on InP with (NH 4 ) 2 S treatment showed good electrical characteristics owing to the reduction of native oxides and sulfur passivation. The electrical characteristics were further improved with an ultrathin Si interface passivation layer (IPL) through reductions in Fermi-level pinning and interface state density. Moreover, during the SiO 2 deposition, the HF in the growth solution simultaneously and effectively removed native oxides from the Si-IPL and provided fluorine passivation on it. The Al/SiO 2 /Si-IPL/(NH 4 ) 2 S-treated InP MOS capacitor showed superior electrical properties. The leakage current density reached 6.9 ' 10 %9 and 1.6 ' 10 %7 A/cm 2 at +2 V. The interface state density reached 3.6 ' 10 11 cm %2 eV %1 with low frequency dispersion of 12.3%.

Metal oxide semiconductor-based Schottky diodes: a review of recent advances

“…It was also found that the Poole-Frenkel emission dominates the reverse current in both diodes, indicating the presence of structural defects and trap levels in the dielectric film. The density of states values for Au/BST/n-InP with Rs was found to be 2.97×10 11 eV -1 cm -2 , which is of the same order as in [44].…”