Abstract: A method (100) for decreasing an excess carrier induced degradation in a silicon substrate, includes providing (120, 130) a charged insulation layer capable of retaining charge on the silicon substrate for generating a potential difference between the charged insulation layer and the silicon substrate, and heat treating (140) the silicon substrate for enabling an impurity causing the excess carrier induced degradation and being in the silicon substrate to diffuse due to the potential difference into a boundary of the silicon substrate and the insulation layer.

Abstract: A method (100) for decreasing an excess carrier induced degradation in a silicon substrate, includes providing (120, 130) a charged insulation layer capable of retaining charge on the silicon substrate for generating a potential difference between the charged insulation layer and the silicon substrate, and heat treating (140) the silicon substrate for enabling an impurity causing the excess carrier induced degradation and being in the silicon substrate to diffuse due to the potential difference into a boundary of the silicon substrate and the insulation layer.

Abstract: The invention presents a method for determining the copper concentration of the substrate using the photoconductivity method in a new manner, the method comprising steps in which the photoconductivity property of the substrate is measured for a first time by an arrangement, the surface of the substrate is illuminated by illuminating means emitting photon radiation, the photoconductivity property of the substrate is measured for a second time by an arrangement, and the copper concentration of the substrate is determined from the change between the first and second time of measurement on the basis of the illumination. The invention also presents an arrangement and a software product for determining the copper concentration.