This study examined the structure and perpendicular magnetization of FePt films grown on Pt/Fe/MgO(100) buffered Si(100) substrates by molecular beam epitaxy. The [Fe(0.17nm)/Pt(0.2nm)]$_N$ multilayers were prepared at room temperature to form a $L1_0$-FePt phase after vacuum annealing. Perpendicular magnetic anisotropy (PMA) was observed in the films after at least 15 repetitions (N = 15) of Fe/Pt deposition and annealing at $300{^{circ}C}$ for 1 hour. Careful structural analysis of the films was carried out by x-ray diffraction and high-resolution transmission electron microscopy. These results will assist in the development of the low temperature $L1_0$- FePt deposition process, which will be essential for future extremely high density magnetic recording media.