According to various examples, a method for non-destructive detection of defects in a semiconductor die is described. The method may include positioning an emitter above the semiconductor die. The method may include generating an emitted wave using the emitter that is directed to a focal point on a surface of the die. The method may include generating a reflected wave from the focal point. The focal point may act as a point source reflecting the emitted wave. The method may include positioning a receiver above the die to receive the reflected wave. The method may also include measuring the reflected wave to detect modulations in amplitude in the reflected wave.