Resist reflow measurement key and method of forming a fine pattern of a semiconductor device using the same

Abstract

In a resist reflow measurement key, and method of fabricating a fine pattern of a semiconductor device using the same, the resist reflow measurement key includes a first reflow key including a plurality of first pattern elements each having a first pattern with a first radius of curvature located on a first side of a first center line and a second pattern with a second radius of curvature located on a second side of the first center line, and a second reflow key including a plurality of second pattern elements each having a third pattern with a third radius of curvature located on a first side of a second center line and a fourth pattern with a fourth radius of curvature located on a second side of the second center line, the second reflow key being formed on a same plane of a substrate as the first reflow key.

1 . A resist reflow measurement key, comprising: 
 a first reflow key disposed on a substrate around a first center point, the first reflow key including a plurality of first pattern elements each having a first pattern with a first radius of curvature located on a first side of a first center line extending in a lengthwise direction of each of the plurality of first pattern elements and a second pattern with a second radius of curvature located on a second side of the first center line, which is opposite to the first side of the first center line; and    a second reflow key disposed on the substrate around a second center point, the second reflow key including a plurality of second pattern elements each having a third pattern with a third radius of curvature located on a first side of a second center line extending in a lengthwise direction of each of the plurality of second pattern elements and a fourth pattern with a fourth radius of curvature located on a second side of the second center line, which is opposite to the first side of the second center line, the second reflow key being formed on a same plane as the first reflow key.    
     
     
         2 . The resist reflow measurement key as claimed in  claim 1 , wherein the first reflow key has a rectangular shape and the plurality of first pattern elements is four first pattern elements, each one of the four first pattern elements constituting a side of the rectangular shaped first reflow key.  
     
     
         3 . The resist reflow measurement key as claimed in  claim 1 , wherein the second reflow key has a rectangular shape and the plurality of second pattern elements is four second pattern elements, each one of the four second pattern elements constituting a side of the rectangular shaped second reflow key.  
     
     
         4 . The resist reflow measurement key as claimed in  claim 1 , wherein 
 the first pattern of each of the plurality of first pattern elements is a plurality of first pattern shape portions positioned at the first side of the first center line and having the first radius of curvature, and the second pattern of each of the plurality of first pattern elements is a plurality of second pattern shape portions positioned at the second side of the first center line and having the second radius of curvature, which is larger than the first radius of curvature, and    the third pattern of the plurality of second pattern elements is a plurality of third pattern shape portions positioned at the first side of the second center line and having the third radius of curvature, and the fourth pattern of the plurality of second pattern elements is a plurality of fourth pattern shape portions positioned at the second side of the second center line and having the fourth radius of curvature, which is larger than the third radius of curvature.    
     
     
         5 . The resist reflow measurement key as claimed in  claim 4 , wherein 
 the plurality of first pattern elements are respectively arranged such that the plurality of second pattern shape portions is disposed facing a first direction of a line extending diagonally through the first center point, and    the plurality of second pattern elements are respectively arranged such that the plurality of fourth pattern shape portions is disposed facing a second direction, which is opposite to the first direction, of a line extending diagonally through the second center point.    
     
     
         6 . The resist reflow measurement key as claimed in  claim 4 , wherein the first and second reflow keys are respectively arranged such that at least one of the plurality of first pattern shape portions of the plurality of first pattern elements faces a corresponding one of the plurality of third pattern shape portions of the plurality of second pattern elements.  
     
     
         7 . The resist reflow measurement key as claimed in  claim 4 , wherein the first reflow key and the second reflow key are respectively arranged such that at least one of the plurality of second pattern shape portions of the plurality of first pattern elements faces a corresponding one of the plurality of fourth pattern shape portions of the plurality of second pattern elements.  
     
     
         8 . The resist reflow measurement key as claimed in  claim 6 , wherein the first reflow key and the second reflow key are respectively arranged such that at least one of the plurality of first pattern shape portions of the plurality of first pattern elements faces a corresponding one of the plurality of third pattern shape portions of the plurality of second pattern elements and at least one of the plurality of second pattern shape portions of the plurality of first pattern elements faces a corresponding one of the plurality of fourth pattern shape portions of the plurality of second pattern elements concurrently.  
     
     
         9 . The resist reflow measurement key as claimed in  claim 4 , wherein the first radius of curvature and the third radius of curvature are the same.  
     
     
         10 . The resist reflow measurement key as claimed in  claim 4 , wherein the second radius of curvature and the fourth radius of curvature are the same.  
     
     
         11 . The resist reflow measurement key as claimed in  claim 1 , wherein the second reflow key has a size smaller than a size of the first reflow key.  
     
     
         12 . The resist reflow measurement key as claimed in  claim 11 , wherein the second reflow key is formed in a region defined by the first reflow key.  
     
     
         13 . The resist reflow measurement key as claimed in  claim 1 , wherein the first and second reflow keys are each of a trench type pattern.  
     
     
         14 . The resist reflow measurement key as claimed in  claim 1 , wherein the first and second reflow keys are each of a mesa type pattern.  
     
     
         15 . The resist reflow measurement key as claimed in  claim 1 , wherein the first reflow key and the second reflow key are formed of a material selected from positive photoresist and negative photoresist.  
     
     
         16 . A method of forming a fine pattern of a semiconductor device, the method comprising: 
 forming a resist pattern on a semiconductor substrate to form a pattern having a predetermined shape;    forming a resist reflow measurement key on the semiconductor substrate while forming the resist pattern;    reflowing the resist pattern and the resist reflow measurement key at the same time;    measuring a variation in a position of a first center point of the reflowed resist reflow measurement key and a variation in a position of a second center point of the reflowed resist reflow measurement key by using an optical overlay measurement apparatus; and    determining a critical dimension of the reflowed resist pattern from measurement values of the variation in the position of the first center point and the variation in the position of the second center point.    
     
     
         17 . The method as claimed in  claim 16 , wherein the pattern having the predetermined shape is a contact hole pattern or a line and space pattern.  
     
     
         18 . The method as claimed in  claim 16 , wherein the optical overlay measurement apparatus is a laser scan alignment (LSA) type overlay measurement apparatus or a field image alignment (FIA) type overlay measurement apparatus.  
     
     
         19 . The method as claimed in  claim 16 , wherein the resist pattern and the resist reflow measurement key are formed of an identical material.  
     
     
         20 . The method as claimed in  claim 16 , wherein the semiconductor substrate comprises a device region where an actual device is formed, and a test element group (TEG) region where a test device for measuring an electrical property of the actual device is formed, 
 the resist pattern being formed in the device region, and    the resist reflow measurement key being formed in the TEG region.