Seed selection through ion channeling to produce uniformly oriented polycrystalline Si films on SiO 2

Abstract

4800 Å polycrystalline silicon films deposited via low-pressure chemical vapor deposition at 620°C on oxidized wafers have been amorphized by silicon ion implantation at normal incidence and subsequently recrystallized at 700° C. As a result of this implant/anneal treatment, the average grain size was enhanced from 700 to 3000 Å, and the 〈110〉 directions in the silicon film were confined to within ±4° normal to the substrate, compared to ± 20° in the as-deposited layer. This is the first time that the channeling implant technique is used to produce uniformly oriented polycrystalline films on amorphous substrates.