Effect of encapsulation temperature on Si:P δ-doped layers

We present a systematic study of the effect of encapsulation temperature on dopant segregation and electronic transport in Si:P δ-doped layers. We demonstrate that while limited dopant segregation and complete electrical activation can be achieved at room temperature, a δ-doped layer encapsulated at ∼250°C represents the best compromise between high electrical quality (mobility ∼61cm2V−1s−1 and phase coherence length ∼72nm at 4.2K) and minimal dopant segregation. Higher encapsulation temperatures are shown to lead to significant dopant segregation.