Reticles, And Methods Of Mitigating Asymmetric Lens Heating In Photolithography

Abstract

A method of mitigating asymmetric lens heating in photolithographically patterning a photo-imageable material using a reticle includes determining where first hot spot locations are expected to occur on a lens when using a reticle to pattern a photo-imageable material. The reticle is then fabricated to include non-printing features within a non-printing region of the reticle which generate additional hot spot locations on the lens when using the reticle to pattern the photo-imageable material. Other implementations are contemplated, including reticles which may be independent of method of use or fabrication.

1 . A reticle comprising:
 a focal plane and a reticle field area within the reticle focal plane upon which incident radiation is projected, the reticle field area comprising a live pattern area within the reticle focal plane from which patterned radiation is emitted, the reticle field area comprising a non-printing border area within the reticle focal plane upon which incident radiation is projected, the non-printing border area being transmissive of some of the incident radiation; and   patterned non-printing features within the non-printing border area.   
     
     
         2 . The reticle of  claim 1  wherein the non-printing features are sized, shaped, and positioned to generate hot spot locations on a lens of an optic system with which the reticle is used. 
     
     
         3 . The reticle of  claim 2  wherein the non-printing features are sized, shaped, and positioned to generate the hot spot locations on the lens within areas which contribute to more uniform heat distribution across the lens. 
     
     
         4 . The reticle of  claim 1  wherein the reticle is a dark field reticle and comprises opaque material, the non-printing features comprising openings through the opaque material. 
     
     
         5 . The reticle of  claim 1  wherein the non-printing border area surrounds the live pattern area. 
     
     
         6 . The reticle of  claim 1  wherein the patterned non-printing features are substantially incident radiation transparent. 
     
     
         7 . The reticle of  claim 1  wherein the patterned non-printing features are substantially incident radiation opaque. 
     
     
         8 . A reticle comprising:
 a focal plane within which a plurality of printing features are received;   a reticle field area within the reticle focal plane upon which incident radiation is projected, the reticle field area comprising a live pattern area within which the plurality of printing features are received within the reticle focal plane and from which patterned radiation is emitted; and   a non-printing region outside of the focal plane and over the reticle field area, the non-printing region comprising patterned non-printing features therein.   
     
     
         9 . The reticle of  claim 8  wherein the non-printing features are sized, shaped, and positioned to generate hot spot locations on a lens of an optic system with which the reticle is used. 
     
     
         10 . The reticle of  claim 9  wherein the non-printing features are sized, shaped, and positioned to generate the hot spot locations on the lens within areas which contribute to more uniform heat distribution across the lens. 
     
     
         11 . The reticle of  claim 8  wherein closest surfaces of material from which the patterned non-printing features are fabricated are spaced at least 0.75 micron perpendicularly away from the reticle focal plane. 
     
     
         12 . The reticle of  claim 8  wherein closest surfaces of material from which the patterned non-printing features are fabricated are spaced at least 1.0 micron perpendicularly away from the reticle focal plane 
     
     
         13 . The reticle of  claim 8  wherein the patterned non-printing features are of a sub-resolution size if such were received within the focal plane in the live pattern area. 
     
     
         14 . The reticle of  claim 8  wherein the reticle comprises a radiation transmissive core, the patterned non-printing features being formed with projections from a surface of the radiation transmissive core. 
     
     
         15 . A reticle comprising:
 a focal plane within which a plurality of printing features are received; and   a pellicle spaced from the focal plane and comprising patterned non-printing features.   
     
     
         16 . The reticle of  claim 15  wherein the non-printing features are sized, shaped, and positioned to generate hot spot locations on a lens of an optic system with which the reticle is used. 
     
     
         17 . The reticle of  claim 16  wherein the non-printing features are sized, shaped, and positioned to generate the hot spot locations on the lens within areas which contribute to more uniform heat distribution across the lens. 
     
     
         18 . The reticle of  claim 15  wherein the reticle is a dark field reticle and comprises opaque material, the non-printing features comprising openings through the opaque material. 
     
     
         19 . The reticle of  claim 15  wherein the pellicle has an incoming radiation side and an outgoing radiation side, the patterned non-printing features being formed on both the incoming radiation side and the outgoing radiation side. 
     
     
         20 . The reticle of  claim 15  wherein the pellicle comprises radiation transmissive core material, the patterned non-printing features being received within the radiation transmissive core material.