Applied Materials, Inc.
INTERFERENCE IN-SENSITIVE LITTROW SYSTEM FOR OPTICAL DEVICE STRUCTURE MEASUREMENT

Abstract:

Embodiments described herein provide for devices and methods of measuring a pitch P of optical device structures and an orientation angle .PHI. of the optical device structures. One embodiment of the system includes an optical arm coupled to an arm actuator. The optical arm includes a light source. The light source emits a light path operable to be diffracted to the stage. The optical arm further includes a first beam splitter and a second beam splitter positioned in the light path. The first beam splitter directs the light path through a first lens and the second beam splitter directs the light path through a first dove prism and a second lens. The optical arm further includes a first detector operable to detect the light path from the first lens and second detector operable to detect the light path from the second lens.