Apparatus for removing liquid in immersion lithography process and method of immersion lithography
View Patent ↗An apparatus for removing an immersion lithography liquid and a method of immersion lithography are disclosed, that rapidly and easily remove liquid from a wafer before development and after exposure. The apparatus includes a housing device configured to prevent the exposure chamber from being contaminated with a scattered liquid; a (rotatable) stage inside the housing device, configured to support a substrate; and (i) a motor configured to rotate the stage or (ii) a gas-spraying device or nozzle above the stage, configured to spray the substrate with an inert gas. The method generally includes coating a photoresist on a substrate; immersing the substrate in a liquid; exposing the substrate; removing the liquid from the substrate by (i) rotating the stage and/or substrate or (ii) spraying the substrate with an inert gas; and developing the photoresist.
1. A method of immersion lithography comprising:
coating a photoresist on a substrate;
immersing the substrate in a liquid having a refractive index greater than or equal to 1.4;
exposing the substrate;
removing the liquid from the substrate by rotating the stage and/or substrate at high speed; and
developing the photoresist.
2. The method of claim 1 , wherein the substrate is rotated at 3000 rpm or more.
3. The method of claim 1 , further comprising spraying the substrate with an inert gas when removing the liquid from the substrate.
4. The method of claim 1 , wherein the step of removing the liquid from the substrate is performed in an exposure device or chamber.
5. The method of claim 1 , wherein the step of removing the liquid from the substrate is performed in a development device or chamber.
6. The method of claim 1 , wherein the liquid comprises one or more salts.
7. The method of claim 1 , wherein the liquid comprises an organic compound.
8. The method of claim 1 , wherein the liquid has a refractive index greater than or equal to 1.6.
9. A method of immersion lithography comprising:
coating a photoresist on a substrate;
immersing the substrate in a liquid having a refractive index greater than or equal to 1.4;
exposing the substrate;
removing the liquid from the substrate by spraying the substrate with an inert gas; and
developing the photoresist.
10. The method of claim 9 , wherein the inert gas comprises nitrogen (N 2 ).
11. The method of claim 10 , wherein the inert gas consists essentially of nitrogen (N 2 ).
12. The method of claim 9 , wherein the step of removing the liquid from the substrate is performed in an exposure device or chamber.
13. The method of claim 9 , wherein the step of removing the liquid from the substrate is performed in an development device or chamber.
14. The method of claim 9 , wherein the liquid comprises one or more salts.
15. The method of claim 9 , wherein the liquid comprises an organic compound.
16. The method of claim 9 , wherein the liquid has a refractive index greater than or equal to 1.6.