Adjustable dummy fill

Abstract

A method of placing a dummy fill layer on a substrate is disclosed (FIG. 2 ). The method includes identifying a sub-region of the substrate ( 210 ). A density of a layer in the sub-region is determined ( 212 ). A pattern of the dummy fill layer is selected to produce a predetermined density ( 216 ). The selected pattern is placed in the sub-region ( 208 ).

1 . A method of placing a dummy fill layer on a substrate, comprising:
 a) identifying a sub-region of the substrate;   b) determining a density of a layer in the sub-region;   c) selecting a pattern of the dummy fill layer to produce a predetermined density; and   d) placing the pattern of the dummy fill layer in the sub-region.   
     
     
         2 . A method as in  claim 1 , comprising:
 e) partitioning the substrate into plural sub-regions including the sub-region;   f) determining a density of the layer in each respective sub-region;   g) selecting a respective pattern of the dummy fill layer to produce the predetermined density in each respective sub-region; and   h) placing the respective pattern of the dummy fill layer in said each respective sub-region.   
     
     
         3 . A method as in  claim 2 , comprising:
 selecting a global target layer density for the plural of sub-regions;   determining if the dummy fill layer density of the plural sub-regions is within the global target layer density;   selecting a new local target layer density for each of the plural of sub-regions and repeating steps (g) through (h) if the dummy fill layer density of the plural sub-regions is not within the global target layer density; and   placing the respective pattern in said each respective sub-region of the plural sub-regions if the dummy fill layer density of the plural sub-regions is within the global target layer density.   
     
     
         4 . A method as in  claim 1 , comprising:
 identifying a blocking area of the substrate; and   identifying the sub-region of the substrate apart from the blocking area.   
     
     
         5 . A method as in  claim 1 , wherein the predetermined density of each of the plural sub-regions is within 10 percent of the predetermined density of the sub-region. 
     
     
         6 . A method as in  claim 1 , wherein the substrate is a reticle for producing a semiconductor device. 
     
     
         7 . A method as in  claim 1 , wherein the substrate comprises a semiconductor device. 
     
     
         8 . A method as in  claim 1 , wherein the layer comprises a capacitor. 
     
     
         9 . A method as in  claim 8 , wherein the capacitor is a ferroelectric capacitor. 
     
     
         10 . A method as in  claim 1 , wherein the layer comprises metal. 
     
     
         11 . A method as in  claim 1 , wherein most of the substrate is filled with fixed dummy fill patterns. 
     
     
         12 . A pattern of a composite layer of a semiconductor device, comprising:
 a drawn layer pattern having a first density; and   an extracted layer pattern separate from the drawn layer pattern and having a second density,   wherein the first density and the second density form a substantially uniform density of the pattern of the composite layer.   
     
     
         13 . A pattern as in  claim 12 , comprising at least one blocking area of the pattern of the composite layer, wherein the extracted layer pattern is separate from the at least one blocking area. 
     
     
         14 . A pattern as in  claim 12 , wherein the pattern of the composite layer is formed on a reticle for producing a semiconductor device. 
     
     
         15 . A pattern as in  claim 12 , wherein the pattern of the composite layer is formed on a semiconductor device. 
     
     
         16 . A pattern as in  claim 12 , wherein the composite layer comprises a capacitor. 
     
     
         17 . A pattern as in  claim 16 , wherein the capacitor comprises a ferroelectric capacitor. 
     
     
         18 . A pattern as in  claim 12 , wherein the composite layer comprises metal. 
     
     
         19 . A method of placing a dummy fill layer on a substrate, comprising:
 identifying a plurality of sub-regions of the substrate;   determining a density of a layer in each respective sub-region;   selecting a first pattern of the dummy fill layer to place in a first of the plurality of sub-regions; and   selecting a second pattern of the dummy fill layer to place in a second of the plurality of sub-regions.   
     
     
         20 . A method as in  claim 19 , comprising:
 identifying a blocking area of the substrate; and   identifying the sub-region of the substrate apart from the blocking area.   
     
     
         21 . A method as in  claim 19 , comprising:
 partitioning the substrate into plural sub-regions including the first and second sub-region; and   determining a density of the layer in each respective sub-region.   
     
     
         22 . A method as in  claim 19 , wherein a final layer density of the first sub-region is within 10 percent of a final layer density of the second the sub-region. 
     
     
         23 . A method as in  claim 19 , wherein the first pattern of the dummy fill layer is placed in the first of the plurality of sub-regions in a single step. 
     
     
         24 . A method as in  claim 19 , wherein the second pattern is iteratively selected to produce a desired final layer density of the second sub-region. 
     
     
         25 . A method of placing a dummy fill layer on a die, comprising:
 identifying a plurality of super cells of the die;   determining a density of a layer in each respective super cell;   selecting a first pattern of the dummy fill layer to place in a first super cell of the plurality of super cells; and   selecting a second pattern of the dummy fill layer to place in a second of the plurality of super cells.   
     
     
         26 . A method as in  claim 25 , comprising:
 identifying a blocking area of the super cell; and   identifying the sub-region of the super cell apart from the blocking area.   
     
     
         27 . A method as in  claim 25 , wherein a final layer density of the first super cell is within 10 percent of a final layer density of the second the super cell. 
     
     
         28 . A method as in  claim 25 , wherein the second pattern is iteratively selected to produce a desired final layer density of the second super cell. 
     
     
         29 . A method as in  claim 28 , wherein the second super cell is placed a plurality of times with the desired final layer density. 
     
     
         30 . A method as in  claim 25 , wherein the at least one of the super cells comprises repeated cells, and wherein the dummy fill layer pattern is placed in each of the repeated cells. 
     
     
         31 . A method as in  claim 29 , wherein the dummy fill layer pattern is placed in one of the repeated cells and repeated with each subsequent placement of said one of the repeated cells.