Apparatus for detecting wafer edge defects and method of using

Abstract

An apparatus for detecting defects in a wafer edge and a method for detecting are disclosed. In the apparatus, an ultrasonic detection unit is used to detect crazing or micro-cracks in a wafer edge, while a laser detection unit is used for detecting cracks in the wafer edge. The ultrasonic detection unit and the laser detection unit may be positioned in a detection module together with a wafer platform for holding and rotating a wafer positioned thereon. The detection module is placed in a mini-environment of clean room conditions which also include a robot transport device and a wafer storage cassette. The present invention novel apparatus is compact in size and can be moved to any location in a fab plant such that it is positioned adjacent to a process machine. The present invention novel apparatus can be used to detect crazing (or micro-cracks) and cracks that are present in an edge portion of a wafer which may be caused by external stresses during various processing steps such as polishing, cleaning and edge bead rinsing.

Dependencies are inferred from the claim text.