Lithographic apparatus, device manufacturing method and a substrate

Abstract

A substrate is provided with a coating of material which is substantially transparent to the wavelength of the projection beam. The coating may be thicker than the wavelength of the projection beam and have a refractive index of the coating such that the wavelength of the projection beam is shortened as it passes through it. This allows the imaging of smaller features on the substrate. Alternatively, the coating may be used with a liquid supply system and act to keep bubbles away from a radiation sensitive layer of the substrate.

1 .- 20 . (canceled) 
   
   
       21 . A device manufacturing method, comprising projecting a patterned beam of radiation through a liquid onto a target portion of a substrate, a surface of the substrate having a contact angle with the liquid of less than or equal 70°. 
   
   
       22 . The method of  claim 21 , wherein the contact angle is in the range of from 50 to 70°. 
   
   
       23 . The method of  claim 21 , wherein the substrate has a resist and the surface of the substrate is a surface above the resist. 
   
   
       24 . The method of  claim 21 , wherein the substrate has a resist and a topcoat having the contact angle is provided on the resist. 
   
   
       25 . The method of  claim 24 , wherein the topcoat comprises a fluorinated polymer in an amount sufficient to provide the contact angle. 
   
   
       26 . The method of  claim 24 , wherein the topcoat is insoluble in the liquid. 
   
   
       27 . The method of  claim 24 , wherein the topcoat prevents bubbles sticking to a resist layer or a resist stack provided on the substrate. 
   
   
       28 . A substrate for use in liquid immersion lithography, the substrate having a resist provided on a surface thereof and having a contact angle to the liquid of less than 70°. 
   
   
       29 . The substrate of  claim 28 , wherein the contact angle is in the range of 50 to 70°. 
   
   
       30 . The substrate of  claim 28 , wherein the substrate has a resist and the surface of the substrate is a surface above the resist. 
   
   
       31 . The substrate of  claim 28 , wherein the substrate has a resist and a topcoat having the contact angle is provided on the resist. 
   
   
       32 . The substrate of  claim 31 , wherein the topcoat comprises a fluorinated polymer in an amount sufficient to provide the contact angle. 
   
   
       33 . The substrate of  claim 31 , wherein the topcoat is insoluble in the liquid. 
   
   
       34 . A device manufacturing method comprising:
 providing a liquid between a projection system of a lithographic projection apparatus and a substrate, the substrate comprising a non-radiation sensitive material being at least partially transparent to radiation, being of a different material than the liquid, and being provided over a part of a radiation sensitive layer of the substrate; and   projecting a patterned beam of radiation, through the liquid, onto a target portion of the substrate using the projection system.   
   
   
       35 . The method according to  claim 34 , wherein the non-radiation sensitive material has a thickness, the radiation has a wavelength and the thickness is greater than the wavelength. 
   
   
       36 . The method according to  claim 34 , wherein the non-radiation sensitive material has a thickness of at least 5 μm. 
   
   
       37 . The method according to  claim 34 , wherein the non-radiation sensitive material has a thickness that is at least 10 μm or at least 20 μm. 
   
   
       38 . The method according to  claim 34 , wherein the non-radiation sensitive material has a first refractive index, the liquid has a second refractive index, and the first refractive index is within 0.2 of the second refractive index. 
   
   
       39 . The method according to  claim 38 , wherein the first refractive index is one of within 0.1 of and substantially the same as the second refractive index. 
   
   
       40 . The method according to  claim 34 , wherein the non-radiation sensitive material has a refractive index in the range of 1.0 to 1.9. 
   
   
       41 . The method according to  claim 34 , wherein the non-radiation sensitive material is substantially insoluble in and unreactive with the liquid. 
   
   
       42 . The method according to  claim 34 , wherein a further protective material is present between the radiation sensitive layer and the non-radiation sensitive material. 
   
   
       43 . The method according to  claim 34 , wherein the non-radiation sensitive material is of a thickness effective to substantially reduce the effect of bubbles in the liquid, of particles in the liquid, or both on the quality of the patterned beam impinging on the radiation sensitive layer. 
   
   
       44 . The method according to  claim 34 , further comprising at least partly coating the radiation sensitive layer of the substrate with the non-radiation sensitive material. 
   
   
       45 . A device manufacturing method comprising:
 providing a liquid, between a projection system of a lithographic projection apparatus and a substrate, to a non-radiation sensitive material on the substrate, the non-radiation sensitive material, which is at least partially transparent to radiation, provided over at least a part of a radiation sensitive layer of the substrate and having a thickness effective to substantially reduce the effect of bubbles in the liquid, of particles in the liquid, or both on the quality of a patterned beam impinging on the radiation sensitive layer; and   projecting a patterned beam of radiation, through the liquid, onto a target portion of the substrate using the projection system.