Photolithography process for semiconductor device

Abstract

Provided is a non-transitory computer readable medium including instructions to generate a level sensor map and create a compensation map from the level sensor map. The level sensor map includes a first determination of a first height above a reference plane of a feature disposed on a semiconductor substrate, and a second determination of a second height above the reference plane of a second feature disposed on a semiconductor substrate. The first and second feature are in a single exposure field. The compensation map includes a determination of at least one parameter to be used during exposure of a single field during an exposure process for the semiconductor substrate.

1 . A non-transitory computer readable medium, comprising computer-readable instructions to determine a photolithography parameter, the computer-readable instructions comprising instructions to:
 generate a level sensor map, wherein the level sensor map includes a first determination of a first height above a reference plane of a feature disposed on a semiconductor substrate, and a second determination of a second height above the reference plane of a second feature disposed on a semiconductor substrate, wherein the first and second feature are in a single exposure field; and   create a compensation map based on generated level sensor map, wherein the compensation map includes a determination of at least one parameter to be used during exposure of a single field during an exposure process for the semiconductor substrate.   
     
     
         2 . The non-transitory computer readable medium of  claim 1 , wherein the at least one parameter includes a determination of a first focus length for a first region of the semiconductor substrate and a determination of a second focus length for a second region of the semiconductor substrate, wherein the first and second regions are within the single exposure field. 
     
     
         3 . The non-transitory computer readable medium of  claim 1 , wherein the at least one parameter includes a determination of a first electrical field to apply to a variable focusing device while exposing a first region of the semiconductor substrate and a determination of a second electrical field to apply to the variable focusing device while exposing a second region of the semiconductor substrate, wherein the first and second regions are within the single exposure field. 
     
     
         4 . The non-transitory medium of  claim 1 , wherein the at least one parameter includes a determination of a first distance to apply between the semiconductor substrate and a lens while exposing a first region of the semiconductor substrate and a determination of a second distance to apply between the semiconductor substrate and the lens while exposing a second region of the semiconductor substrate, wherein the first and second regions are within the single exposure field. 
     
     
         5 . The non-transitory computer readable medium of  claim 1 , wherein the at least one parameter includes a determination of a first configuration of a retical edge mask assembly (REMA) to while exposing a first region of the semiconductor substrate and a determination of a second configuration of the REMA while exposing a second region of the semiconductor substrate, wherein the first and second regions are within the single exposure field. 
     
     
         6 . A method of photolithography, including:
 determining a first level of the substrate and a second level of the substrate using a level sensor, wherein the first and second levels are a single exposure field of a step-and-scan process;   generating a level map including the first level and the second level; and   using the generated level map to determine a first parameter and a second parameter setting during an exposure process of the single exposure field; and   using the determined first parameter and the second parameter to expose the single exposure field of the substrate.   
     
     
         7 . The method of  claim 6 , wherein the first level includes determinations of a slope of a feature disposed on the substrate. 
     
     
         8 . The method of  claim 6 , wherein first parameter is a first focus length for exposing the substrate and the second parameter is a second focus length for exposing the substrate in the single exposure field. 
     
     
         9 . The method of  claim 8 , wherein the using the determined first and second parameters includes:
 using the first parameter to determine a first deformation of a membrane;   deforming a transparent membrane according to the first deformation, thereby providing a first deformed membrane;   passing the provided radiation beam through the first deformed membrane to provide the first focus length; and   exposing the substrate to the radiation beam, after the radiation beam has passed through the first deformed membrane.   
     
     
         10 . The method of  claim 9 , further comprising:
 thereafter, deforming the transparent membrane according to the second parameter, thereby providing a second deformed membrane to provide the second focus length;   passing the provided radiation beam through the second deformed membrane; and   exposing the substrate to the radiation beam after the radiation beam has passed through the second deformed membrane, wherein the exposing the substrate to the radiation beam after the radiation beam has passed through the first deformed membrane and the exposing the substrate to the radiation beam after the radiation beam has passed through the second deformed membrane is performed in a single exposure field.   
     
     
         11 . The method of  claim 6 , further comprising:
 wherein the using the determined first parameter and the second parameter to expose the single exposure field of the substrate is performed as one of a plurality of shots of the step-and-scan process used to expose a horizontal path across of the substrate.   
     
     
         12 . A method, comprising:
 using a level sensor to identify a first height of a first feature on the substrate and a second height of a second feature on the substrate, wherein the first and second height are in a single exposure field of a photolithography tool;   sending the first height and the second height to a controller,   using the controller to determine a first focus length and a second focus length for a variable focusing device of the photolithography tool; and   using the photolithography tool to perform a step-and-scan process to expose the single exposure field of the substrate using the first focus length and the second focus length.   
     
     
         13 . The method of  claim 12 , wherein the variable focusing device includes a membrane. 
     
     
         14 . The method of  claim 13 , wherein the variable focusing device is configured to provide the first focus length when a first electric field is applied to the membrane and provide the second focus length with a second electric field is applied to the membrane. 
     
     
         15 . The method of  claim 12 , wherein the using the level sensor includes generating a level sensor map including the first height and the second height. 
     
     
         16 . The method of  claim 15 , wherein the level sensor map further includes a plurality of additional heights in addition to the first height and the second height. 
     
     
         17 . The method of  claim 12 , further comprising:
 using the level sensor to determine a slope of the first feature.   
     
     
         18 . The method of  claim 12 , wherein the using the controller to determine the first focus length and the second focus length includes creating a compensation map based on the received first and second heights, wherein the compensation map includes the first focus length to be used to expose the first feature and the second focus length to be used to expose the second feature. 
     
     
         19 . The method of  claim 12 , further comprising:
 using the level sensor to identify a third height of a third feature on the substrate and a fourth height of a fourth feature on the substrate, wherein the third and fourth height are in a second exposure field of the photolithography tool;   sending the third height and the fourth height to the controller,   using the controller to determine a third focus length and a fourth focus length for the variable focusing device of the photolithography tool; and   using the photolithography tool to expose, using the step-and-scan process, the second exposure field using the third focus length and the fourth focus length.   
     
     
         20 . The method of  claim 19 , wherein the single exposure field and the second exposure field are each one of a plurality of shots of the step-and-scan process used to expose a horizontal path across of the substrate.