Heavily dopedp+andn+silicon epitaxial layers were continuously grown at 600 °C using photoenhanced epitaxy. The heavily phosphorus‐doped photoepitaxial layer with a carrier concentration above 1×1017cm−3grown on thep−substrate shows very high density surface pits due to phosphorus precipitation, suggesting poor crystal quality. Unexpectedly, when thisn+photoepitaxial layer is continuously grown on a heavily boron‐dopedp+photoepitaxial layer at a boron concentration above 1×1019cm−3, surface pits completely disappear and crystal quality is greatly improved. The very low growth temperature enabled an extremely abrupt impurity profile to be achieved for thep+‐n+layer.