Abstract: Methods of processing a silicon wafer for an electronic circuit, substrates for an electronic circuit, and device manufacturing methods are disclosed. According to an embodiment the method of processing a silicon wafer comprises impregnating the silicon wafer with impurities that form one or more deep energy levels within the band gap of silicon, wherein at least one of said deep energy levels is positioned at least 0.3 eV away from the conduction band if the level is a donor level or at least 0.3 eV away from the valence band if the level is an acceptor level, wherein: said impregnating step is performed in such a way that the ratio between the maximum concentration of said impurities in said silicon wafer and the average concentration of said impurities in said silicon wafer is less than 7:1.