Continuous growth of heavily dopedp+hyphen;n+Si epitaxial layer using lowhyphen;temperature photoepitaxy

摘要

Heavily dopedp+andn+silicon epitaxial layers were continuously grown at 600thinsp;deg;C using photoenhanced epitaxy. The heavily phosphorushyphen;doped photoepitaxial layer with a carrier concentration above 1times;1017cmminus;3grown on thepminus;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 boronhyphen;dopedp+photoepitaxial layer at a boron concentration above 1times;1019cmminus;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+hyphen;n+layer.