Patent ID: 11892777
Assignee: WAYMO LLC
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An exposure unit comprising:
a photomask;
at least one wiper device, wherein the at least one wiper is configured to clean at least one surface of the photomask;
a particle- or bubble-detection device;
a fluid feeding and cleaning unit configured to provide a fluid, wherein the fluid feeding and cleaning unit comprises one or more filters, wherein the one or more filters comprise: a 0.2 micron filter, a 0.1 micron filter, and a 0.04 micron filter; and
a controller having at least one processor and a memory, wherein the at least one processor executes program instructions stored in the memory so as to carry out operations, the operations comprising:
receiving, from the particle- or bubble-detection device, information indicative of particles or bubbles present on the photomask; and
in response to receiving the information indicative of particles or bubbles present on the photomask, controlling the at least one wiper device to clean at least one surface of the photomask.