公开(公告)号：US20210349403A1

公开(公告)日：2021-11-11

申请号：US17383086

申请日：2021-07-22

Applicant: ASML Netherlands B.V.

Inventor： Johannes Fitzgerald De Boer ,  Vasco Tomas Tenner ,  Arie Jeffrey Den Boef ,  Christos Messinis

IPC: G03F7/20 ,  G01N21/88

Abstract: Methods and apparatus are disclosed for determining a characteristic of a structure. In one arrangement, the structure is illuminated with first illumination radiation to generate first scattered radiation. A first interference pattern is formed by interference between a portion of the first scattered radiation reaching a sensor and first reference radiation. The structure is also illuminated with second illumination radiation from a different direction. A second interference pattern is formed using second reference radiation. The first and second interference patterns are used to determine the characteristic of the structure. Azimuthal angles of the first and second reference radiations onto the sensor are different.

公开(公告)号：US11119415B2

公开(公告)日：2021-09-14

申请号：US16376639

申请日：2019-04-05

Applicant: ASML Netherlands B.V.

Inventor： Johannes Fitzgerald De Boer ,  Vasco Tomas Tenner ,  Arie Jeffrey Den Boef ,  Christos Messinis

IPC: G03F7/20 ,  G01N21/88

Abstract: Methods and apparatus are disclosed for determining a characteristic of a structure. In one arrangement, the structure is illuminated with first illumination radiation to generate first scattered radiation. A first interference pattern is formed by interference between a portion of the first scattered radiation reaching a sensor and first reference radiation. The structure is also illuminated with second illumination radiation from a different direction. A second interference pattern is formed using second reference radiation. The first and second interference patterns are used to determine the characteristic of the structure. Azimuthal angles of the first and second reference radiations onto the sensor are different.