Superstrate and a method of using the same
A body of a superstrate can be used to form an adaptive planarization layer over a substrate that has a non-uniform topography. A body of a superstrate can have bending characteristics that are well suited to achieve both conformal and planarization behavior. The body can have a surface and a thickness in a range of t 1 to t 2 , t 1 =(Pd 4 /2Eh) 1/3 ; t 2 =(5Pd 4 /2Eh) 1/3 ; P is a pressure corresponding to a capillary force between the body and a planarization precursor material; d is a bending distance; E is Young's modulus for the body; and h is a step height difference between two adjacent regions of a substrate. In an embodiment, a thickness can be selected and used to determine the maximum out-of-plane displacement, w max , for conformal behavior is sufficient and that w max for planarization behavior is below a predetermined threshold.
1. A superstrate for forming a planarization layer on a substrate comprising:
a body having a surface and a thickness in a range of t 1 to t 2 , wherein:
t 1 =( Pd 4 /2 Eh ) 1/3 ,
t 2 =(5 Pd 4 /2 Eh ) 1/3 ,
P is a pressure corresponding to a sum of contributions from a capillary force between the body and formable precursor material, and a gas pressure applied to the superstrate,
d is a bending distance,
E is Young's modulus for the body, wherein 0<E≤70×10 9 N/m 2 and
h is a step height difference between two adjacent regions of the substrate and wherein t 1 is between 0.2 mm and 0.95 mm and t 2 is between 0.25 mm and 1.1 mm.
2. The superstrate of claim 1 , wherein the superstrate has a conformal behavior area that has an out-of-plane displacement of at least 5 nm.
3. The superstrate of claim 2 , wherein the conformal behavior area has a length of at least 0.20 mm.
4. The superstrate of claim 1 , wherein the superstrate has a planarizing behavior area that has an out-of-plane displacement of at most 1 nm.
5. The superstrate of claim 4 , wherein the planarizing behavior area has a bending distance of at most 0.1 mm.
6. The superstrate of claim 1 , wherein the body includes a glass.
7. The superstrate of claim 1 , wherein the body includes a polymer.
8. The superstrate of claim 1 , wherein the body has a transmittance greater than 70% for radiation used to polymerize a planarization precursor material that is used to form a planarization layer.
9. A superstrate for forming a planarization layer on a substrate comprising:
a body made from a single glass material, wherein the body has a thickness within a range of 0.20 mm to 0.95 mm, and wherein the thickness is further within a range of t 1 to t 2 , wherein:
t 1 =( Pd 4 /2 Eh ) 1/3 ,
t 2 =(5 Pd 4 /2 Eh ) 1/3 ,
P is a pressure corresponding to a sum of contributions from a capillary force between the body and formable precursor material, and a gas pressure applied to the superstrate,
d is a bending distance,
E is Young's modulus for the body, and
h is a step height difference between two adjacent regions of the substrate.
10. A superstrate for forming a planarization layer on a substrate comprising:
a body made from a single polyethylene material, wherein the body has a thickness within a range of 0.25 mm to 1.1 mm, and wherein the thickness is further within a range of t 1 to t 2 , wherein:
t 1 =( Pd 4 /2 Eh ) 1/3 ,
t 2 =(5 Pd 4 /2 Eh ) 1/3 ,
P is a pressure corresponding to a sum of contributions from a capillary force between the body and formable precursor material, and a gas pressure applied to the superstrate,
d is a bending distance,
E is Young's modulus for the body, and
h is a step height difference between two adjacent regions of the substrate.