公开(公告)号：US11275312B1

公开(公告)日：2022-03-15

申请号：US17107072

申请日：2020-11-30

Applicant: Waymo LLC

Inventor： James Dunphy ,  Hongqin Shi ,  David Hutchison ,  Yeh-Jiun Tung ,  Eric Copenhaver ,  Nao Chuei

IPC: G03F7/20

Abstract: The present application relates to contact immersion lithography systems and methods of their use. An example immersion lithography system includes a photomask substrate and at least one sensor disposed along a surface of the photomask substrate. The immersion lithography system also includes a controller having at least one processor and a memory. The at least one processor is configured to execute program instructions stored in the memory so as to carry out operations. The operations include receiving, from the at least one sensor, information indicative of an electric field proximate to the at least one sensor. The operations also include determining, based on the received information, at least one of: a thickness of a liquid layer adjacent to the photomask substrate or a distance to a further substrate adjacent to the photomask substrate.