Method and apparatus for ultrasonic scanning of a fabrication wafer

摘要

A method and apparatus for ultrasonic scanning of a wafer assembly is disclosed. The wafer assembly is held in a wafer chuck and rotated. A transducer generates ultrasound in the wafer assembly and the ultrasound emitted from the wafer assembly is sensed. A controller adjusts the relative positions of the wafer and the transducer and controls the transducer to generate ultrasound at a number of scan points.