Embossed mask lithography
View Patent ↗Disclosed are layered groupings and methods for constructing digital circuitry, such as memory known as Permanent Inexpensive Rugged Memory (PIRM) cross point arrays which can be produced on flexible substrates by patterning and curing through the use of a transparent embossing tool.
1. A method for producing digital circuitry by an emboss and lift off process, said process comprising the steps of:
coating a surface of a flexible substrate with at least one film;
coating said film on said flexible substrate with a photo curable polymer, so as to form a first layered grouping having a top side and a bottom side, said bottom side being substantially in contact with said flexible substrate;
embossing a plurality of substantially parallel depressions having trench portions and peak portions on said polymer by use of a substantially transparent embossing tool;
curing said photo curable polymer with light energy directed through said substantially transparent embossing tool;
patterning said first layered grouping by etching of an area comprising said plurality of depressions through to said surface of said substrate substantially contiguous with the trench portions of said depressions within said first layered grouping
applying a transfer polymer layer to said top side of said first layered grouping;
inverting said first layered grouping;
lifting off said flexible substrate so as to expose a substantially planar surface on said bottom side of said first layered grouping;
providing a second layered grouping substantially in accordance with said coating, forming, embossing, curing and patterning steps of the first layered grouping;
applying said second layered grouping on said exposed substantially planar surface of said bottom side of said first layered grouping in such a way that said substantially parallel linear depressions of said first and second layered groupings are in a substantially orthogonal juxtaposition to each other.
2. A method for producing digital circuitry as claimed in claim 1 , wherein said process of embossing utilizes at least one stamper substantially formed from at least one material from the group comprising UV curable silicone rubbers.
3. A method for producing digital circuitry as claimed in claim 1 , wherein said etching of said patterning process comprises an antistrophic etch so that a lateral definition of said trench partitions may be preserved.
4. A method for producing digital circuitry as claimed in claim 1 , wherein said etching of said patterning process comprises a reactive ion etch.
5. A method for producing digital circuitry as claimed in claim 1 , wherein said films of said first and second layered groupings may be thin films formed from at least one material from the group of materials comprising metals, dielectrics, and semiconductors.
6. A method for producing digital circuitry as claimed in claim 1 , wherein said photo polymer is a UV curable polymer and said light energy comprises UV light.
7. A method for producing circuitry as claimed in claim 2 , wherein said process of embossing utilizes at least one stamper substantially formed from at least from poly dimethyl siloxane.