Immersion photolithography system and method using microchannel nozzles

Abstract

A liquid immersion photolithography system includes an exposure system that exposes a substrate with electromagnetic radiation and includes a projection optical system that focuses the electromagnetic radiation on the substrate. A liquid supply system provides liquid flow between the projection optical system and the substrate. An optional plurality of micronozzles are arranged around the periphery of one side of the projection optical system so as to provide a substantially uniform velocity distribution of the liquid flow in an area where the substrate is being exposed.

What is claimed is: 
     
         1 . A liquid immersion photolithography system comprising:
 an exposure system that exposes a substrate with electromagnetic radiation and includes a projection optical system that focuses the electromagnetic radiation on the substrate;   a liquid supply system that provides liquid flow between the projection optical system and the substrate; and   a plurality of micronozzles arranged in two-dimensional array around a periphery of the projection optical system so as to provide the liquid flow between the substrate and the projection optical system.   
     
     
         2 . The liquid immersion photolithography system of  claim 1 , wherein the plurality of micronozzles include a plurality of tubes of varying lengths. 
     
     
         3 . The liquid immersion photolithography system of  claim 1 , wherein the varying lengths of the tubes provide a velocity profile that compensates for non-uniformities. 
     
     
         4 . The liquid immersion photolithography system of  claim 1 , wherein the liquid supply system includes:
 an input channel for delivering the liquid into a first plenum;   a first diffuser screen through which the liquid can flow into a second plenum, wherein the liquid can then flow into the micronozzles.   
     
     
         5 . The liquid immersion photolithography system of  claim 4 , wherein the liquid supply system further comprises:
 a second plurality of micronozzles removing the liquid from the exposure area into a third plenum;   a second diffuser screen through which the liquid flows into a fourth plenum; and an output channel through which the liquid is circulated.   
     
     
         6 . The liquid immersion photolithography system of  claim 1 , wherein the projection optical system includes a housing with a gas seal between the housing and the substrate. 
     
     
         7 . The liquid immersion photolithography system of  claim 6 , wherein the housing includes a plurality of annular channels connected to the gas seal through which negative pressure is maintained around the exposure area so as to remove stray liquid. 
     
     
         8 . The liquid immersion photolithography system of  claim 1 , wherein the micronozzles are between 5 microns and 5 millimeters in diameter. 
     
     
         9 . The liquid immersion photolithography system of  claim 1 , wherein the micronozzles are slit-shaped. 
     
     
         10 . The liquid immersion photolithography system of  claim 1 , wherein at least some of the micronozzles include a portion that flares out into an area between the substrate and the projection optical system. 
     
     
         11 . The liquid immersion photolithography system of  claim 1 , wherein a direction of the liquid flow is reversible. 
     
     
         12 . The liquid immersion photolithography system of  claim 1 , wherein the liquid supply system includes at least three channels through which liquid can flow. 
     
     
         13 . The liquid immersion photolithography system of  claim 1 , wherein the liquid supply system compensates for non-uniformities in a velocity profile. 
     
     
         14 . A liquid immersion photolithography system comprising:
 an exposure system that exposes an exposure area on a substrate with electromagnetic radiation and includes a projection optical system;   means for providing a liquid flow between the projection optical system and the exposure area; and   a first microshower having a two-dimensional array of nozzles at one side of the projection optical system that provides the liquid flow in the exposure area.   
     
     
         15 . The liquid immersion photolithography system of  claim 14 , wherein the microshower includes a plurality of tubes of varying lengths. 
     
     
         16 . The liquid immersion photolithography system of  claim 15 , wherein the varying lengths of the tubes provide a velocity profile that compensates for non-uniformities. 
     
     
         17 . The liquid immersion photolithography system of  claim 14 , further comprising a liquid supply system that includes:
 an input channel for delivering the liquid into a first plenum;   a first diffuser screen through which the liquid can flow into a second plenum,   wherein the liquid flows into the exposure area through the microshower.   
     
     
         18 . The liquid immersion photolithography system of  claim 15 , wherein the liquid supply system further comprises:
 a second microshower for removing the liquid from the exposure area into a third plenum;   a second diffuser screen through which the liquid can flow into a fourth plenum; and   an output channel through which the liquid can circulate out of the exposure area.   
     
     
         19 . The liquid immersion photolithography system of  claim 14 , wherein the projection optical system includes a housing with a gas seal between the housing and the substrate. 
     
     
         20 . A liquid immersion photolithography system comprising:
 an exposure system that exposes an exposure area on a substrate with electromagnetic radiation and includes a projection optical system; and   a two-dimensional array of nozzles around a periphery of a lens of the projection optical system that provide a liquid flow in the exposure area.