Effect of heat treatments on the electrical resistivity of Sb-doped amorphous Si films deposited by molecular beam on (100) Si

Abstract

Amorphous silicon films, doped with antimony at a relative high concentration of ∼(4-5)×1020 cm-3, were deposited by means of a molecular beam on (100) Si substrates. These films were subsequently heat treated at temperatures between 500 and 700°C for times between 5 s and 12 h. It was found that at 500°C the resistivity decreased with time during solid phase epitaxial growth of the amorphous films and induced electrical activation of Sb "quenched-in" the Si. At the higher temperatures, however, after an initial decrease to a minimum value the resistivity increased with the heat treatment time as a result of a precipitation of Sb from the supersaturated crystallized Si films. The times to obtain the minimum values of the resistivity are consistent with the rates of the solid phase epitaxial growth of amorphous Si films on (100) Si given in the literature for the various temperatures.