Ion beam assisted crystallization of amorphous silicon layers using high current density Gallium beams

We have investigated ion beam assisted crystallization as a possible method for the creation of crystalline Si layers on amorphous substrates. Ion beam assisted crystallization has previously been characterised with pulsed and modest continuous beam current densities, but not at the high densities that would be required for high throughput processes. In this study, amorphous Si layers were implanted with Ga using a focused ion beam (FIB) tool and with Ga, Ar, Ge and As using beamline implanters. Crystallization was only observed for Ga, implying Ga alone was acting to reduce the activation energy. The observed rates of crystallization also implied that the relaxation state of the a-Si, influenced by the beam conditions, was an important driver for the phase transformation.