Search

EP-4735956-A1 - METHOD FOR USING A HARD STAMP TO PRODUCE A SOFT STAMP

EP4735956A1EP 4735956 A1EP4735956 A1EP 4735956A1EP-4735956-A1

Abstract

The invention relates to a method and a device for embossing a soft stamp and also to an embossing device and to a soft stamp. During the embossing with the hard stamp, structures are produced on the soft stamp, and a coating for reducing the adhesive properties is provided on the soft stamp.

Inventors

  • ZORBACH, Walter
  • KHAN, Jonas

Assignees

  • EV Group E. Thallner GmbH

Dates

Publication Date
20260506
Application Date
20230629

Claims (15)

  1. 1. Method for embossing a soft stamp (6) with the following steps: i) providing a hard stamp (4) with a first layer (3), ii) applying a second layer (2) directly on the first layer (3), iii) embossing the soft stamp (6) with the hard stamp (4), wherein the second layer (2) is fixed to the soft stamp (6), iv) separating the soft stamp (6) from the hard stamp (4) so that the second layer (2) is transferred to the soft stamp (6).
  2. 2. The method according to claim 1, wherein during the embossing in step iii) a soft stamp embossing compound (6) of the soft stamp (6) is applied directly to the second layer (2).
  3. 3. Method according to one of the preceding claims, wherein the embossing in step iii) further comprises hardening the soft stamp (6).
  4. 4. Method according to one of the preceding claims, wherein during the application in step ii) the first layer (3) is completely wetted by the second layer (2).
  5. 5. Method according to one of the preceding claims, wherein the first layer (3) and the second layer (2) are anti-adhesion layers (2, 3, 93) for reducing adhesive forces between interfaces.
  6. 6. The method according to claim 5, wherein the anti-adhesive layers (2, 3, 93) at least partially comprise tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane [CF3-(CF2)5-(CH2)2-SiC13], and/or 1,1,2,2-perfluorodecyltrichlorosilane [CF3-(CF2)7-(CH2)2-SiC13], and/or 1H,1H,2H,2H-perfluorooctyltrimethoxysilane [CF3-(CF2)5-(CH2)2-SiO(CH3)3, F13-TMS], and/or perfluoropolyether molecules.
  7. 7. Method according to one of the preceding claims, wherein the respective materials of the first layer (3) and the second layer (2) are different.
  8. 8. Method according to one of the preceding claims, wherein the first Layer (3) and the second layer (2), in particular along a structured surface of the hard stamp (4), each have a uniform thickness of less than 5 nm, preferably less than 3 nm, particularly preferably less than 1 nm, most preferably less than 0.3 nm.
  9. 9. Method according to one of the preceding claims, wherein the first layer (3) and/or the second layer (2) are applied by spin coating, spray coating, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), dip coating, doctor blade coating or molecular beam deposition (MBE, molecular beam epitaxy).
  10. 10. Method according to one of the preceding claims, wherein the soft stamp (6) at least partially comprises polydimethylsiloxane (PDMS), and/or perfluoropolyether (PFPE), polyhedral oligomeric silsesquioxane (POS S) and/or polydimethylsiloxane (PDMS) and/or tetraethylorthosilicate (TEOS) and/or poly(organo)siloxanes (silicone) and/or thermoplastics and/or thermosets.
  11. 1 1. Method according to one of the preceding claims, wherein a first adhesion force between the second layer (2) and the first layer (3) is lower than a second adhesion force between the second layer (2) and the soft stamp (6).
  12. 12. Method according to one of the preceding claims, wherein the hard stamp (4) is formed from at least one of the following materials: glass, metal, metal alloy, ceramic or semiconductor material, preferably silicon, cured polymer.
  13. 13. Device for embossing a soft stamp (6) with a hard stamp (4) according to the embossing method according to at least one of the preceding claims, at least comprising: - a hard stamp (4) with a first layer (3), - coating agent for applying a second layer (2) to the first layer (3), - embossing means for embossing the soft stamp (6) with the hard stamp (4), wherein the second layer (2) can be fixed on the soft stamp (6), - Separating means for separating the soft stamp (6) from the hard stamp (4), wherein the second layer (2) is transferable to the soft stamp (6).
  14. 14. Device according to claim 13, wherein the device further comprises hardening means for solidifying the soft stamp (6), wherein the hardening means are adapted to harden the soft stamp during embossing before the release means act.
  15. 15. Soft stamp (6) manufactured according to the method according to at least one of claims 1 - 12, wherein the soft stamp (6) has the second layer (2).

Description

Description Method for producing a soft stamp with a hard stamp The present invention relates to a method for producing, in particular for embossing, a soft stamp or a soft stamp embossing compound with a master stamp. These master stamps or hard stamps have structures to be molded, which are transferred to the soft stamp during embossing. In the prior art, micro and/or nanostructures are regularly produced either photolithographically and/or with the help of imprint lithography. Imprint lithography is a process in which micro and/or nanometer sized structures are embossed into a material using a stamp. The material is in particular an embossing material applied to a substrate. Imprint processes of this type have become increasingly important in recent years because they can be carried out more quickly, more effectively and more cost-effectively than many photolithographic processes. Furthermore, it has been shown that the resolution achievable using imprint lithography processes is in no way inferior to the resolution that can be achieved with photolithography. In some cases, such as in the so-called “first print”, better resolution can be achieved with imprint lithography than with conventional lithography. Most embodiments of the known devices for imprint lithography are built into so-called mask aligners or designed as stand-alone systems, which, however, usually cannot process substrates larger than 300 mm. Aligners are particularly suitable for special imprint systems, as they have already been widely used in the semiconductor industry for photolithography. This made it useful for suppliers to offer extensions and attachments that were based on or could extend the already known mask aligner technology. The main advantage of mask aligners is that in most cases they already have optical systems, in particular lamp housings, for illuminating the substrates, and thus the embossed materials, in particular over the entire surface. In addition to modified or extended mask aligners, there are also special imprint systems that are made for and based on special designs. These systems are usually alignment systems that can align a stamp to the substrate with high precision. These systems also have the option of generating a vacuum, special dispensing systems and other modules. Such imprint systems also rarely have the option of embossing an embossing material on a substrate of more than 300 mm. There are imprinting systems that enable the production of structures for display devices, i.e. displays, especially curved or flat screens. There are five known techniques of imprint lithography: • Micro- and/or nanocontact printing (p/nCP) • Replica casting (REM) • Micro-transfer molding (pTM) or nanoimprint lithographic (NIL), • Microforming in capillaries (MIMIC) • solvent assisted microforming (SAMIM). It is known that imprint stamps can be divided into two large families: hard stamps (made of metal, ceramic materials or voluminous glass or plastic) and so-called soft stamps (made of polymers, silicones, etc.) can be used. All imprint stamps have a structured stamp surface, which usually shows the negative of the structure to be created and is molded into the embossing compound. Soft stamps are produced as a negative of a master stamp. Master stamps are stamps that are used to form the original soft stamp. In other words, master stamps are templates for replication. The master stamp is either a hard stamp made of metal, glass, especially quartz glass, plastic or ceramic, which is produced once through correspondingly complex processing, or a soft stamp that is to be molded, especially a soft stamp with an elastic, stiffened carrier. Any number of soft stamps can then be produced from the master stamp. The soft stamps are known to enable conformal, uniform contact over large surfaces. Both the master stamp from the soft stamp and the soft stamp from the embossed surface of the substrate can be separated from each other without damage. Error-free separation of the soft stamp from the master stamp is essential for the production of functioning products. The separability can be the result of a low surface energy of a soft stamp, which is achieved by functionalization, in particular coating. Therefore, after embossing with the master stamp and hardening of the soft stamp embossing compound, soft stamps are coated with a non-stick layer (so-called anti-sticking layer, non-adhesive layer, ASL layer). The soft stamps are easier to separate from the substrate than hard stamps. For automated implementation of soft lithographic processes, it is preferable to support the soft stamp with a carrier. Currently, glass carrier substrates of various thicknesses are widely used. However, the use of thick glass substrates causes the soft stamp to lose at least some of its flexibility. The glass supports are sufficiently thin glass supports that provide the necessary stability for the soft stamp, but are flexible enough to achieve the