Preparation and characterization of polysulfide treated InP MIS structures

It is shown that InP treated with a polysulfide solution prepared by bubbling O₂ through ammonium sulfide with excess sulfur dissolved results in excellent interfaces, whereas polysulfide-free solutions have little effect. Interface state densities of 10¹⁰ cm^-2 eV^-1 as judged by quasi-static CV measurements were obtained on polysulfide treated MIS structures coated with IPCVD SiO₂. Low temperature PL spectra show marked difference on polysulfide treated InP when compared to InP that was treated with commercially available ammonium sulfide. Low temperature gated PL spectra, measured using a semi-transparent gate MIS structure as a function of gate bias, show easier band bending for polysulfide passivated InP. Raman studies indicate smaller depletion widths and lower barrier heights due to lower interface states on such treated samples