The invention relates to the manufacture of an epitaxial layer, with the following steps: providing a semiconductor substrate; providing a Si—Ge layer on the semiconductor substrate, having a first depth; —providing the semiconductor substrate with a doped layer with an n-type dopant material and having a second depth substantially greater than said first depth; performing an oxidation step to form a silicon dioxide layer such that Ge atoms and n-type atoms are pushed into the semiconductor substrate by the silicon dioxide layer at the silicon dioxide/silicon interface, wherein the n-type atoms are pushed deeper into the semiconductor substrate than the Ge atoms, resulting in a top layer with a reduced concentration of n-type atoms; removing the silicon dioxide layer; growing an epitaxial layer of silicon on the semiconductor substrate with a reduced outdiffusion or autodoping.