Modifying Polycrystalline Films Through Ion Channelling

Abstract

ABSTRACTA novel low-temperature process to enhance the grain size of a polycrystalline film on an amorphous substrate has been previously reported. In this process, ion implantation is used to selectively anorphize the film, and undamaged grains act as seed crystals in a subsequent low-temperature anneal. In this work, a 120 nm polycrystalline silicon film was implanted from three angles with phosphorous at 150°K. The total dose was l.0×l015/cm2 . Transmission electron micrographs after a partial anneal (700°C for 30 minutes) indicate that some crystallites survived implantation due to ion channelling in the (111) plane. After a 60 minute anneal at 700°C, 7 μm grains were observed.