| abstract |
The invention relates to a semiconductor wafer with a front and a back and an epitaxial layer of semiconducting material deposited on the front. The semiconductor wafer is characterized in that the epitaxial layer has a maximum local flatness value SGQR max of equal to or less than 0.13 μm and a maximum density of 0.14 scattered light centers per cm 2, and the front side of the semiconductor wafer has a layer before the epitaxial layer is deposited Surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 _m x 1 _m large reference surface. DOLLAR A The invention further relates to a method for producing the semiconductor wafer. The method comprises the following process steps: DOLLAR A (a) as the only polishing step, simultaneous polishing of the front and the back of the semiconductor wafer between rotating polishing plates with the supply of an alkaline polishing sol, the semiconductor wafer being in a recess in a rotor disk, the thickness of which is 2 to 20 _m is smaller than the thickness of the finished polished semiconductor wafer: DOLLAR A (b) simultaneous treatment of the front and the back of the semiconductor wafer between rotating polishing plates while adding a liquid containing at least one polyhydric alcohol with 2 to 6 carbon atoms, DOLLAR A (c) cleaning and drying the semiconductor wafer; and DOLLAR A (d) depositing the epitaxial layer on ... |