Optical Beam Induced Resistance Change (OBIRCH) uses imaging technique via laser beam to induce a thermal change within a test specimen. By laser stimulation, defect area will be highlighted differently in thermal characteristics within the defect-free. The technique is by using the laser heating the defective area locally and the resulting changes in resistance can be detected by monitoring the input current to the device. OBIRCH is particularly useful for detecting electro-migration effect occur in open metal gaps.
OBIRCH is commonly used together with Photon Emission Microscope (PEM) for defect localization and fault characterization in failure analysis due to today's increasing integration and complexity of microelectronic devices in the industries.