Abstract: A semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface, wherein the surface of the epitaxial layer has a maximum density of 0.14 localized light scatterers per cm2 with a cross section of greater than or equal to 0.12 &mgr;m, and the front surface of the semiconductor wafer, prior to the deposition of the epitaxial layer, has a surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 &mgr;m×1 &mgr;m reference area. There is also a process for producing a semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface.