US Patent 7718962 Defect imaging device and method

The present invention is directed to a defect imaging device that has an energy beam that is directed at a device under test. The energy beam creates positrons deep within the material of the device under test. When the positrons combine with electrons in the material they produce a pair of annihilation photons. The annihilation photons are detected. The Doppler broadening of the annihilation photons is used to determine if a defect is present in the material. Three dimensional images of the device under test are created by directing the energy beam at different portions of the device under test.