1. A system comprising: a light source configured to direct collimated light at an edge of a stacked wafer; a detector disposed opposite the light source, wherein the detector is configured to acquire a shadow-gram image of the edge of the stacked wafer; and a controller operatively connected to the detector, wherein the controller is configured to: receive the shadow-gram image; and compare characteristics of the shadow-gram image with predetermined measurements to inspect an edge profile of the stacked wafer.