Method and apparatus for determining generation lifetime of product semiconductor wafers

To determine the generation lifetime of a pn junction of a semiconductor wafer, an elastically deformable, electrically conductive contact is caused to touch a surface of the semiconductor wafer over the pn junction. At least one reverse bias voltage is applied to the pn junction via the contact and a value of current flowing in the contact in response to the application of each reverse bias voltage is measured. The generation lifetime of the pn junction is then determined from a subset of the values of the reverse bias voltage and the corresponding values of measured current.