公开(公告)号：US11662669B2

公开(公告)日：2023-05-30

申请号：US17625466

申请日：2020-06-15

Applicant: ASML Netherlands B.V.

Inventor： Andrey Valerievich Rogachevskiy ,  Martin Jules Marie-Emile De Nivelle ,  Arjan Gijsbertsen ,  Willem Richard Pongers ,  Viktor Trogrlic

IPC: G03F9/00 ,  G03F7/20

CPC classification number: G03F9/7092 ,  G03F7/7085 ,  G03F9/7026 ,  G03F9/7034

Abstract: An apparatus for measuring a height of a substrate for processing in a lithographic apparatus is disclosed. The apparatus comprises a first sensor for sensing a height of the substrate over a first area. The apparatus also comprises a second sensor for sensing a height of the substrate over a second area. The apparatus further comprises a processor adapted to normalize first data corresponding to a signal from the first sensor with a second sensor footprint to produce a first normalized height data, and to normalize second data corresponding to a signal from the second sensor with a first sensor footprint to produce a second normalized height data. The processor is adapted to determine a correction to a measured height of the substrate based on a difference between the first and second normalized height data.