Residual Layer Thickness Measurement and Correction

Abstract

In nano-imprint lithography it is important to detect thickness non-uniformity of a residual layer formed on a substrate. Such non-uniformity is compensated such that a uniform residual layer may be formed. Compensation is performed by calculating a corrected fluid drop pattern.

1 . In an imprint lithography system, a method comprising: 
 a) depositing a plurality of drops of imprint fluid on a substrate, the plurality of drops having a drop pattern in which each of the plurality of drops has an assigned size and position on the substrate;    b) performing an imprint of the plurality of drops of imprint fluid by patterning the imprint fluid between a mold and the substrate resulting in an imprinted layer;    c) measuring a thickness of a residual layer of the imprinted layer;    d) calculating a new drop pattern that compensates for nonuniformities in the thickness of the residual layer by adjusting the assigned size and position of certain ones of the plurality of drops; and    e) repeating step b).    
     
     
         2 . The method as recited in  claim 1 , further comprising repeating step c) after step e).  
     
     
         3 . The method as recited in  claim 2 , wherein steps b), c), and d) are repeated until a desired uniformity of the thickness of the residual layer is achieved.  
     
     
         4 . An imprint lithography system, comprising: 
 a fluid dispense system for depositing a plurality of drops of imprint fluid on a substrate, the plurality of drops having a drop pattern in which each of the plurality of drops has an assigned size and position on the substrate;    an imprint mold for performing an imprint of the plurality of drops of imprint fluid by patterning the imprint fluid between the imprint mold and the substrate resulting in an imprinted layer;    a film thickness measurement tool for measuring a thickness of a residual layer of the imprinted layer;    circuitry for calculating a new drop pattern that compensates for nonuniformities in the thickness of the residual layer by adjusting the assigned size and position of certain ones of the plurality of drops.