Systems and methods for contact immersion lithography

Patent metadata

Field	Value
Publication number	US-11892777-B2
Application number	US-202218046403-A
Country	US
Kind code	B2
Filing date	Oct 13, 2022
Priority date	Dec 23, 2019
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

The present application relates to contact immersion lithography exposure units and methods of their use. An example contact exposure unit includes a container configured to contain a fluid material and a substrate disposed within the container. The substrate has a first surface and a second surface, and the substrate includes a photoresist material on at least the first surface. The contact exposure unit includes a photomask disposed within the container. The photomask is optically coupled to the photoresist material by way of a gap comprising the fluid material. The contact exposure unit also includes an inflatable balloon configured to be controllably inflated so as to apply a desired force to the second surface of the substrate to controllably adjust the gap between the photomask and the photoresist material.

First claim

What is claimed is:

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.

2. The exposure unit of claim 1 , wherein the at least one wiper device comprises a pin and bar arrangement, wherein the pin and bar arrangement comprises one or more springs configured to level the at least one wiper device with respect to the photomask.

3. The exposure unit of claim 1 , wherein the at least one wiper device comprises:
a wiper body, wherein the wiper body is at least partially hollow.

4. The exposure unit of claim 3 , wherein the wiper body comprises a fluid inlet configured to accept a fluid.

5. The exposure unit of claim 4 , wherein the at least one wiper device further comprises a sponge wiper, wherein the sponge wiper is configured to come into contact with the at least one surface of the photomask, wherein the sponge wiper is removably fastenable to the wiper body by way of one or more clips.

6. The exposure unit of claim 5 , wherein the at least one wiper device is configured to accept the fluid at a pressure between zero to 100 pounds per square inch, wherein the sponge wiper is configured to be saturated by the fluid.

7. The exposure unit of claim 5 , wherein the sponge wiper comprises polyvinyl acetate (PVA), ethylene-vinyl acetate (EVA), or an open-cell foam.

8. The exposure unit of claim 1 , further comprising a fluid pump, wherein the fluid pump is configured to provide a fluid to at least one wiper device.

9. The exposure unit of claim 1 , wherein the fluid comprises water, glycol, glycerol, or a mixture thereof.

10. The exposure unit of claim 1 , further comprising:
a light source configured to produce illumination light, wherein the light source is optically coupled to the photomask, wherein the light source is a collimated ultraviolet (UV) lamp.

11. The exposure unit of claim 1 , wherein the at least one wiper device is configured to clean both sides of the photomask.

12. The exposure unit of claim 1 , further comprising:
a one- or two-dimensional actuator configured to controllably adjust a position of the at least one wiper device, wherein the operations further comprise adjusting the position of the wiper device so as to clean the at least one surface of the photomask.

13. A photolithography method comprising:
receiving, from a particle- or bubble-detection device, information indicative of particles or bubbles present on a photomask; and
in response to receiving the information indicative of particles or bubbles present on the photomask, controlling at least one wiper device to physically clean a surface of the photomask; and
causing a fluid to flow through a fluid feeding and cleaning unit and the at least one wiper device, 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.

14. The photolithography method of claim 13 , wherein controlling the at least one wiper device to physically clean the surface of the photomask comprises utilizing a pin and bar arrangement having one or more springs to level the at least one wiper device with respect to the photomask.

15. The photolithography method of claim 13 , wherein the at least one wiper device comprises a wiper body with a fluid inlet configured to accept a fluid.

16. The photolithography method of claim 15 , wherein controlling the at least one wiper device to physically clean the surface of the photomask comprises controlling a fluid pump to provide the fluid to the fluid inlet at a pressure between zero and 100 pounds per square inch.

17. The photolithography method of claim 16 , wherein the at least one wiper device comprises a sponge wiper, wherein controlling the at least one wiper device to physically clean the surface of the photomask further comprises saturating the sponge wiper with the fluid.

Assignees

• Waymo Llc

Inventors

• Shi Hongqin
• Tung Yeh-Jiun
• Dunphy James
• Gensoli Cesar

Classifications

• G03F7/70341 Primary

  Details of immersion lithography aspects, e.g. exposure media or control of immersion liquid supply (chemical composition of immersion liquids G03F7/2041) · CPC title

• G03F7/70925

  Cleaning, i.e. actively freeing apparatus from pollutants, e.g. using plasma cleaning · CPC title

• G03F7/7035

  Proximity or contact printers · CPC title