Ion activation in boron-doped polycrystalline Si thin films prepared on glass substrates

Abstract

Boron-implanted polycrystalline Si thin films were subjected to thermal annealing. Their evolving electrical and structural features were characterized using Hall measurements, Raman Spectroscopy, transmission electron microcopy, and UV-Visible transmittance spectrophotometry. The Raman analysis indicated that boron implantation did not induce structurally significant damage, i.e., lattice distortion. Even low-temperature annealing at 350 °C provided a high degree of activation, keeping the atomic structure restored on the short-range order, as confirmed by transmission electron microscopy and optical transmittance data. At temperatures above 350 °C, the charge carriers exhibited temperature-independent behaviors, with a charge carrier concentration of 6 or 7 × 1019/cm3. The boron-implanted Si thin films were found to be subject to electronic stopping rather than nuclear stopping, thus allowing for low-temperature activation.