3D Mold For Manufacturing Of Sub-Micron 3D Structures Using 2-D Photon Lithography And Nanoimprinting And Process Thereof

• US 20110046764A1
• Filed: 11/23/2009
• Published: 02/24/2011
• Est. Priority Date: 12/22/2008
• Status: Active Grant

• Current Assignee: Helios Applied Systems Pte Limited
• Original Assignee: Helios Applied Systems Pte Limited
• Inventors: Kan, Shyi-Herng
• Granted Patent: US 9,358,737 B2
• Time in Patent Office: Days
• US Class Current: 700/98
• CPC Class Codes: B29D 11/00365 Production of microlenses lenticular sheets B29D11/00278
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G02B 3/04 with continuous faces that are rotationally symmetrical but deviate from a true sphere , e.g. so called "aspheric" lenses
• CPC Class Codes: G02B 3/12 Fluid-filled or evacuated lenses
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
• CPC Class Codes: G03F 7/2053 using a laser ablative removal B41C
• CPC Class Codes: G03F 7/70375 Multiphoton lithography or multiphoton photopolymerization; Imaging systems comprising means for converting one type of radiation into another type of radiation

Abstract

A process to manufacture a 3D mold to fabricate a high-throughput and low cost sub-micron 3D structure product is disclosed. The process integrates use of 2-photon laser lithography and 3D write technology to make a 3D mold of each layer of the 3D structure product, and then use nanoimprinting to form a sheet of polymer film of each layer of the 3D structure from the said 3D mold of that layer. Each layer of the sheet of polymer film is then fabricated into the sub-micron 3D structure product. The 3D mold of each layer of a high-throughput and low cost sub-micron 3D structure product, is further used to make master molds which is then used to form a sheet of polymer film of each layer of the 3D structure to fabricate the sub-micron 3D structure product. Applications using this process are also disclosed.

Claims

1. A process of manufacturing a 3D mold to fabricate a high-throughput and low cost sub-micron 3D structure product, said process integrating 2-photon lithography and nanoimprinting, comprising using 2-photon laser lithography and 3D write technology to make a 3D mold of each layer of the 3D structure product, using nanoimprinting to form a sheet of polymer film of each layer of the 3D structure from said 3D mold of that layer, and fabricating each layer to make the sub-micron 3D structure product.

25. A process of manufacturing a 3D mold as claimed in claim 1, wherein the process follows the NIL process flow, and comprises:

Using improved designs in mold manufacturing with library of shapes to establish design rules for mass manufacturing of 3D devices, making molds with these 3D templates and

using stamp on NIL thermal, UV, stamping and roll-to-roll technology.

2. A 3D mold of a layer of a high-throughput and low cost sub-micron 3D structure product, wherein the 3D mold of the layer is created by a process comprising using 2-photon laser lithography and 3D write technology to make a 3D mold of each layer of the 3D structure product and using nanoimprinting to form a sheet of polymer film of each layer of the 3D structure to make the 3D mold of that layer of the sub-micron 3D structure product.

21. A 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 2, wherein the mold made of flexible polymer is attached onto the surface of a cylinder to form a roller of flexible polymer mold, for nanoimprinting.

22. A 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 2, wherein the mold made of sheet metal is attached onto the surface of a cylinder to form a roller of sheet metal mold with polymer features, for nanoimprinting.

23. A 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 2, wherein the mold made of sheet aluminum is attached onto the surface of a cylinder to form a roller of sheet aluminum mold with metal features stamped on using a nickel master mold, for nanoimprinting.

24. A 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 2, wherein the mold made of sheet metal having metal features electroplated onto its surface is attached onto the surface of a cylinder to form a roller of sheet metal mold with metal features, for nanoimprinting.

28. A process to manufacture a 3D mold used to fabricate a high-throughput and low cost sub-micron 3D structure products as claimed in claim 22, wherein nanoimprinting comprises Thermal NIL thermal, UV NIL or Roll-to-Roll nanoimprinting.

29. A plurality of 3D molds as claimed in claim 2, used to create a plurality of layers of 3D structures, said structures selected from the group consisting of:

a. Organ/tissue scaffolds fabricated by slicing a 3D CAD design of the scaffold into multiple layers, each layer being individually fabricated using nanoimprint to overlay and bond all layers to form the final scaffolds, creating such scaffolds which are anatomically similar to those created in vivo physical environment.

b. Tissue engineering scaffolds; and

c. medical implantable devices

30. A 3D mold as claimed in claim 2, to fabricate simple 3D structures, wherein a single stamping nanoimprinting process is used.

31. A 3D mold as claimed in claim 2, to fabricate simple 3D structures, wherein the material used in the NIL process comprises either synthetic or biological material.

3. A 3D mold of a layer of a high-throughput and low-cost sub-micron 3D structure product using a process which integrates 2-photon lithography and nanoimprinting, wherein the 3D mold of the layer is manufactured by a process comprising:

creating a design of a 3D layer of the 3D structure;

setting up a writing process to produce an 3D image of the layer of the 3D structure product using a 2-photon lithography tool;

developing a photo resist/polymer of the 3D image of the layer on a substrate;

sputtering one or more layers of metal onto the surface of the photoresist/polymer of the 3D image of the layer to form a seed metal layer; and

transferring the 3D polymer image coated with the seed metal layer by an electroplating process to form a 3D metal mold;

wherein the 3D metal mold is used to manufacture a copy of the 3D image of the same layer of the 3D structure product.

4. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the step of creating a design of a 3D layer includes anchoring the base of 3D CAD at the surface of the substrate, compensating for polymer shrinking and making it mechanically strong to prevent the sub micron 3D structure from collapsing during the rinsing and drying process.

5. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the 3D image of said layer produced by said writing process comprises an image from 0.01 micron to 150 microns in thickness.

6. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the 3D image of said layer produced by said writing process comprises an image of 100 microns thickness.

7. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the parameters of said layer is used as input for the manufacture of a mold of that layer and wherein said layer is from 0.01 microns to 100 microns in thickness.

8. The 3D mold of a layer of the sub-micron 3D structure product layer as claimed in claim 3, wherein the parameters of said layer is used as input for the manufacture of a mold of that layer and wherein said layer is 100 microns in thickness.

9. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein said layer of the 3D image is from 0.01 microns to 150 microns in thickness.

10. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the step of developing a photo resist/polymer of the 3D image comprises cleaning the substrate, applying a spin coat resist onto the substrate, removing any photo resist on the back of the substrate with a solvent, pre-baking the substrate, placing the substrate on a vacuum chuck, turning on the vacuum, aligning a wafer, inputting the process parameters, marking and checking the substrate to ensure that every device is correctly positioned and removing the photo resist/polymer of the slice of the image of that layer of the substrate.

11. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the step of forming a seed metal layer by sputtering one or more layers of metal onto the surface of the resist/polymer of the image comprises checking there are no residues of photoresist or other materials left on the substrate, placing the wafer in a sputtering tool, pumping the chamber down to base pressure, performing a short plasma clean process to ensure the surface is clean, depositing one or more metallic layers, layer by layer to form the seed metal layer and removing the wafer from the chamber.

12. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the step of transferring of the polymer image formed from the seed metal layer by an electroplating process to form a metal mold comprises placing the substrate with the seed metal layer in an electroplating bath, setting the electroplating parameters, plating until the desired thickness is achieved, removing the wafer from the holder, removing the resist from the 3D mold, rinsing the mold thoroughly with de ionized water, grinding the back and edges of the 3D mold to size, rinsing the 3D mold in de ionized water, performing O₂ plasma cleaning on the surface of the 3D mold.

13. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the step of transferring of the polymer image formed from the seed metal layer by an electroplating process to form a metal mold comprises placing the substrate with the seed metal layer in an electroplating bath, setting the electroplating parameters, plating until the desired thickness is achieved, removing the wafer from the holder, removing the resist from the 3D mold, rinsing the mold thoroughly with de ionized water, cutting the back and edges of the 3D mold to size, rinsing the 3D mold in de ionized water, and performing O₂ plasma cleaning on the surface of the 3D mold.

14. The 3D mold of a layer of the sub-micron 3D structure product mold as claimed in claim 3, wherein the step of transferring of the polymer image formed from the seed metal layer by an electroplating process to form a metal mold comprises placing the substrate with the seed metal layer in an electroplating bath, setting the electroplating parameters, plating until the desired thickness is achieved, removing the wafer from the holder, removing the resist from the 3D mold, rinsing the mold thoroughly with de ionized water, punching the back and edges of the 3D mold to size, rinsing the 3D mold in de ionized water, and performing O₂ plasma cleaning on the surface of the 3D mold.

15. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the step of fabricating a mold comprises coating a substrate with photoresist, setting the process parameters for the stamping tool, transferring the 3D image from the metal mold onto a large substrate through a series of stamp and step sequence, developing the resist after processing, de-laminating the resist/polymer from the substrate, wrapping the substrate over a jig to form a cylinder, electroplating the cylinder until the desired thickness is achieved, grinding and polishing the cylinder to the correct finish and thickness.

16. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the mold comprises a master mold and secondary molds.

17. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, comprising making 2 roller molds, wherein a mold is made for an upper surface of a layer of a 3D structure and another mold is made for a lower surface of the same layer of a 3D structure, wherein each layer is then aligned and zipped together to adhere together to form multiple layer structures.

18. The 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the nanoimprinting process includes Thermal NIL or UV NIL or Roll-to-roll NIL.

19. A 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the 2-photon lithography comprises software to fabricate 3D molds of any shape and molds of different shapes which can be combined to form complex molds.

20. A 3D mold of a layer of the sub-micron 3D structure product as claimed in claim 3, wherein the initial template is 3D in shape having curved side walls compared to grayscale structures, which have vertical or sloping side walls.

26. A process to manufacture a 3D mold used to fabricate a high-throughput and low cost sub-micron 3D structure product, integrating 2-photon lithography and nanoimprinting, comprising using 2 photon laser lithography and 3D write technology to make a 3D mold of each layer of the 3D structure, using nanoimprinting to form a sheet of polymer film of each layer of the 3D structure from the 3D mold, and stacking each layer of the 3D structure to fabricate the sub-micron 3D structure product.

27. The process to manufacture a 3D mold used to fabricate a high-throughput and low cost sub-micron 3D structure product as claimed in claim 26, using 3D write technology to pattern a template for the 3D mold.

32. A process for the manufacture of scaffolds for tissue engineering, comprising the following steps:

—

a. creating a 3D template using 2-photon lithography;

b. transferring the 3D image onto a 3D mold;

c. designing the structures with a computer aided design program (CAD);

d. using software with the 3D CAD drawing as input to automatically sliced the said structures into multiple layers;

e. eliminating layers with repeated patterns;

f. fabricating templates for mold making;

g. fabricating a master mold for each layer to produce a hard/flexible mold for a stamping/roll-to-roll nanoimprint tool; and

h. sandwiching each layer produced onto each other to form a complete organ scaffold with physical dimensions close to an actual natural scaffold.

33. A process used in the manufacture of medical devices such as bridges for nerves and bones requiring physical cues to guide growth of nerves and bones, comprising the following steps:

—

a. creating a 3D template using 2-photon lithography;

b. transferring the 3D image onto a mold;

c. designing the structures with a computer aided design program (CAD);

d. using software with the 3D CAD drawing as input to automatically sliced the said structures into multiple layers;

e. eliminating layers with repeated patterns;

f. fabricating templates for mold making;

g. fabricating a master mold for each layer to produce a hard/flexible mold for a stamping/roll-to-roll nanoimprint tool; and

h. sandwiching each layer produced onto each other to form a complete organ scaffold with physical dimensions close to an actual natural scaffold.

34. A process for the manufacture of customized micro-lens to form a more functional optical film, comprising the following steps:

—

a. creating a 3D template using 2-photon lithography;

b. transferring the 3D image onto a mold;

c. designing the structures with a computer aided design program (CAD);

d. using software with the 3D CAD drawing as input to automatically sliced the said structures into multiple layers;

e. eliminating layers with repeated patterns;

f. fabricating templates for mold making;

g. fabricating a master mold for each layer to produce a hard/flexible mold for a stamping/roll-to-roll nanoimprint tool; and

h. sandwiching each layer produced onto each other to form a complete optical film made entirely of compound micro-lens with custom designed curvatures;

wherein the optical film is incorporated onto the surface of a thin film or a thin layer of glass to reduce reflection, total internal reflection, collect light and focus the light collected onto active devices.