The formation of a ½ monolayer (ML) of strontium (Sr) on Si(001) represents the most widely used and effective passivation procedure for the epitaxial growth of strontium titanate (SrTiO3) on Si with molecular beam epitaxy (MBE). In the present study we demonstrate experimentally the possibility of preparing such a buffer layer with the pulsed-laser deposition (PLD) technique. In-situ analysis using reflection high-energy electron diffraction (RHEED) showed surface structure evolution from two-domain (2×1)+(1×2), exhibited by the bare silicon surface, to a (3×2)+(2×3) structure at 1/6 ML Sr coverage, which is then replaced by (1×2)+(2×1) structure at ¼ ML and maintained up to ½ ML coverage. In addition, two different processes for the removal of native SiO2 layer were studied: thermal and Sr-induced deoxidation process. Annealing above 1100°C proved to be the most efficient in terms of carbon contamination. The results highlight the possibilities of using the PLD technique for the synthesis of an epitaxial SrTiO3 layer on Si, needed for the integration of different functional oxides with a Si platform.
COBISS.SI-ID: 28399143