Abstract: A method for reliability testing of wafer stage integrated circuit devices wherein a hardness factor is established relating device substrate currents to device lifetimes attributable to interface trap degradation. A beam of ionizing radiation is then directed onto the device until a critical dose is reached, at which time the device fails. The critical dose is plotted against hardness factors so that device lifetimes may be predicted.

Abstract: A test apparatus for electron devices, such as integrated circuits, at the wafer stage of fabrication, wherein a beam of ionizing radiation is directed through an electrical probe card and onto the wafer under test. The probe card and the radiation beam share a common port through which a selected device or group of devices is exposed, but other devices on the wafer are not similarly exposed. A microscope, supported on a frame, is interchangeable with the radiation beam source, sharing the common port, so that a tested device may be observed.