Patent ID: 7057408

Claim:
A method of contacting a contact area with a contact needle or tip in a prober that is deployed for semiconductor wafer or device testing, the contact area being arranged on a free surface of a test semiconductor wafer, the method comprising the steps of: first, positioning the test semiconductor wafer horizontally so that the contact area and the contact needle or tip are aligned one above the other and at a distance from each other; then, moving the test semiconductor wafer vertically in the direction of the contact tip to an ending position at which a contact of the contact needle or tip with the contact area is established by direct observation of the vertical spacing between the contact area and the contact needle or tip wherein the latter step comprises: directly observing the contact needle or tip along a horizontal observation axis in a plane which is at a distance from an expected end position of the free surface of the test semiconductor wafer; and determining the actual ending position of the free surface of the test semiconductor wafer based on an observed vertical deflection of the contact needle or tip.