Low temperature plasma enhanced deposition approach for fabrication of microcrystalline GaP/Si superlattice

Abstract

A plasma technology approach to grow microcrystalline GaP/Si superlattices was explored. The layers of GaP were grown using time modulated plasma enhanced deposition (atomic layer deposition approach), while Si layers were grown using the conventional plasma enhanced chemical vapor deposition mode with high hydrogen dilution. The (3 nm)GaP/(2 nm)Si superlattices were formed on Si and GaP substrates either by the growth of an amorphous GaP/Si multilayer structure followed by thermal annealing at 450–900 °C or by growth of a microcrystalline GaP/Si superlattice at temperatures not exceeding 400 °C. A quantum confinement effect of thin 2 nm Si layers was demonstrated by the appearance of a peak at 500 cm−1 in Raman spectra. The crucial role of hydrogen behavior in Si crystallization and void formation during the annealing of amorphous and growth of microcrystalline GaP/Si structures was demonstrated.