Critical dimension control during template formation
View Patent ↗Thickness of a residual layer may be altered to control critical dimension of features in a patterned layer provided by an imprint lithography process. The thickness of the residual layer may be directly proportional or inversely proportional to the critical dimension of features. Dispensing techniques and material selection may also provide control of the critical dimension of features in the patterned layer.
1. A nanoimprint lithography method for controlling critical dimension variations in patterned features, the method comprising:
determining a dispense pattern for dispensing polymerizable material within a volume defined by an imprint lithography mold when the mold is placed in superimposition with a substrate;
adjusting the dispense pattern to provide for a residual layer having variations in thickness when a patterned layer of polymerizable material is formed using the imprint lithography mold;
dispensing the volume of polymerizable material on the substrate according to the adjusted dispense pattern;
positioning the imprint lithography mold in superimposition with the dispensed polymerizable material on the substrate and contacting the dispensed polymerizable material;
solidifying the polymerizable material to form a patterned layer having a residual layer and a plurality of features, the residual layer having the variations in thickness;
determining thickness of residual layer as a function of location;
applying a first etching composition to the formed patterned layer in a first etching process, wherein the magnitude of and variations in the thickness of the residual layer control the magnitude of variation in the critical dimension of the features; and,
subsequent to applying the first etching composition, applying a second etching composition to the patterned layer to transfer the features into the substrate.
2. The method of claim 1 , wherein the first etching composition is a descum etching composition.
3. The method of claim 1 , wherein the first etching composition is a polymerizing etching composition.
4. The method of claim 1 , where in the first etching composition and the second etching composition are the same.
5. The method of claim 1 , wherein the thickness of the residual layer is greater at the edges of the substrate than at the center of the substrate.
6. The method of claim 1 , wherein the thickness of the residual layer is greater at the center of the substrate than at least one edge of the substrate.
7. The method of claim 1 , wherein applying a second etching composition to the patterned layer to transfer the features into the substrate forms a sub-master template.
8. The method of claim 1 , wherein the imprint mold is included in a sub-master template and applying a second etching composition to the patterned layer to transfer the features into the substrate forms a working template.
9. The method of claim 1 , wherein the imprint mold is included in a master template and applying a second etching composition to the patterned layer to transfer the features into the substrate to form a working template.
10. The method of claim 1 , wherein the polymerizable material comprises a first polymerizable material and a second polymerizable material, the first polymerizable material having a first erosion rate that is greater than the second polymerizable material.
11. The method of claim 1 , wherein the residual layer thickness is proportional to the desired critical dimension.
12. The method of claim 11 , wherein the residual layer thickness is inversely proportional to the desired critical dimension.
13. The method of claim 11 , wherein the residual layer thickness is directly proportional to the desired critical dimension.