Patent ID: 11965834
Assignee: UNITY SEMICONDUCTOR
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 12:
13. A reflecting optical device for reflecting diffuse light radiation from a dark-field optical inspection device, the reflecting optical device comprising a first reflecting optical part and second reflecting optical part, the reflecting optical device comprising a reflective surface configured according to a first reflective zone made on the first optical part to direct a first portion of the diffuse radiation originating from an optical focal point of collection toward a first optical focal point of detection that is optically conjugated with the optical focal point of collection, and according to a second reflective zone made on the second optical part to direct a second portion of the diffuse radiation originating from the optical focal point of collection toward a second optical focal point of detection that is optically conjugated with the optical focal point of collection and distinct from the first optical focal point of detection wherein the first and the second reflective zones correspond to portions of distinct ellipses whose respective main axes form a non-zero angle between them, a first focal point of the ellipses corresponding to the optical focal point of collection, and a second focal point of the ellipses corresponding, respectively, to the first optical focal point of detection and to the second optical focal point of detection of the reflecting optical device.