Diffusion of B and As from polycrystalline silicon during rapid optical annealing

Abstract
The diffusion of B and As from polycrystalline Si into single-crystal Si during rapid optical annealing (ROA) has been investigated. Samples were characterized by secondary ion mass spectrometry, transmission electron microscopy, and sheet resistance measurements. It is demonstrated that very shallow diffusion profiles in the single-crystal Si can be formed by ROA. At 1050 °C/5 s, for instance, a junction depth of ∼35 nm is obtained for As diffusion. The effect of polycrystalline Si/mono-Si interface treatment on the dopant diffusion and the polycrystalline Si grain structure will be discussed.