Ion-beam-induced epitaxy in the Pd/Si system

Epitaxial growth of Pd2Si has been observed at room temperature by implanting energetic Ar ions through a Pd film on a (111) Si substrate. It was found from ion channeling and backscattering measurements that the ion-beam-induced growth was initiated at the Pd-Si interface and the thickness of the grown layer increased with ion dose even after the surface region of the Si substrate had been completely amorphized by Ar ion bombardment. A uniform epitaxial Pd2Si film 120 nm thick was obtained by implanting 200-keV Ar ions to doses higher than 5×1016 cm−2, for which the channeling minimum yield of 1.5-MeV He ions was about 0.1 of the random yield, and diffraction patterns in transmission electron microscopy showed strong single-crystalline spots. Some additional experiments have also been performed to investigate the growth mechanism.