Optical beam induced current (OBIC) introduces photons into devices with a focused and scanned laser. The induced photocurrent image at various pins is captured. Differences in this image compared to a reference image can quickly pinpoint short or open circuits, ESD or over-stress damage, or device-level issues. Since OBIC introduces no charge into the circuit, it causes no damage. The technique can be performed from the back and from the front of devices.
A typical OBIC image consists of an overlay of a photo of the circuitry and a photocurrent map. Each is colorized differently for clarity.
OBIC is a powerful failure analysis technique since it localizes failures non-invasively and requires little in the way of sample preparation. Flip-chip devices, difficult to study by other means, can be studied through the die from the back side. It is an efficient and non-invasive optical analysis technique useful in detecting and localizing certain integrated circuit (IC) failures.
LSM with specimen current amplifier