Influence of growth temperature on minority-carrier lifetime of Si layer grown by liquid phase epitaxy using Ga solvent

The influence of growth temperature on the minority-carrier lifetime of epitaxial Si layers was systematically investigated. Epitaxial Si layers were grown on (111) Si substrates in the temperature range of 500-900 °C by liquid phase epitaxy using Ga solvent. To ensure that the contribution of the annealed Si substrate during growth will be excluded, the overall lifetime of the epitaxial layer and the Si substrate was measured as a function of the thickness of the substrate. This procedure revealed that the minority-carrier lifetime of the epitaxial Si layers increases upon lowering the growth temperature. This can be explained by the lower impurity concentration as measured by secondary-ion mass spectroscopy. Moreover, the existence of a slightly misoriented crystal domain was found in the Si layer grown at a high temperature. These results suggest that low growth temperature should be employed in growing a Si film with high minority-carrier lifetime.