Laser scanning of active semiconductor devices

A laser scanner is described which can nondestructively explore electrical characteristics of semiconductor devices on a point-by-point basis. The results of applying the scanner to electronically map temperature distributions and hot spots in a power transistor are given. The results of mapping localized nonlinearities in electrical operation and 0.5 GHz response are also presented. Pictures show the progress of logic in a MOS shift register and demonstrate the ability to change at will the logical state of an embedded active cell with the laser.