Electrical Characterization of Positively Charged SiO Coatings for MOS Solar Cells
Keywords:Ar coating, thin filme, MOS capacitor, solar cell
This article discusses fabrication, characteriza-tion and studies of the C-V characteristics of SiO layers depos-ited by PVD on Si-p <100> substrates with doping around 1x1016 cm-3. MOS capacitors (Metal-Oxide-Semiconductor) with Al/SiO2/Si-P, Al/SiO/Si-P and Al/SiO/SiO2/Si-P structures were manufactured. It was observed the presence of negative charges in the structure with SiO/SiO2 with density of effective charges Qf ≈ -1x1012 cm-2 and relative permittivity of the die-lectric εr = 2.9. After sintering in ultrapure Ar and N2+H2(10%) the relative permittivity changed to εr = 4.52 and the layers stayed positively charged (Qf = (0.5-1.6)x1012 cm-2), which is adequate for positively charged anti-reflective (AR) coatings of MOS solar cells.