Method of manufacturing a master for a replication process
A method of manufacturing a master for use in a wafer-scale replication process is disclosed. The method comprises at least one step of forming a layer of photoresist on a substrate and exposing the layer of photoresist to a radiation pattern to form at least one patterned layer. The method also comprises a step of developing the at least one patterned layer to provide one or more structures defining the master. In an embodiment, the at least one step of forming the layer of photoresist comprises a process of dry film lamination.
1. A method of manufacturing a master for use in a wafer-scale replication process, the method comprising:
(a) at least one step of forming a layer of photoresist on a substrate and exposing the layer of photoresist to a radiation pattern to form at least one patterned layer; and
(b) a step of developing the at least one patterned layer to provide one or more structures defining the master;
wherein step (b) comprises spraying and/or spin coating the at least one patterned layer with a developer,
wherein a/the process of dry film lamination is used to form one or more layers having a thickness of 5 to 10 micrometers and/or a/the process of spaying/spin-coating a liquid photoresist is used to form one or more layers having a thickness of 5 to 10 micrometers.
2. The method of claim 1 wherein the at least one step of forming the layer of photoresist comprises a process of dry film lamination.
3. The method of claim 1 wherein the at least one step of forming a layer of photoresist comprises a process of spaying and/or spin-coating a liquid photoresist.
4. The method of claim 1 , wherein exposing the layer(s) of photoresist to a radiation pattern comprises projecting one or more radiation patterns onto the/each layer of photoresist directly and/or through a mask.
5. The method of claim 1 wherein step (a) comprises forming a plurality of patterned layers of photoresist on the substrate, and wherein a pattern formed on each consecutive layer of photoresist at least partly corresponds to and/or overlaps a pattern formed on a preceding layer of photoresist.
6. The method of claim 1 , wherein step (a) comprises a step of baking the substrate before and/or after exposing the/each layer of photoresist to the radiation pattern.
7. A method of manufacturing a sub-master for use in a replication process, the method comprising a step of forming a sub-master by a process of replication using a master manufactured according to claim 1 .
8. A method of manufacturing a tool for use in a wafer-scale replication process, the method comprising the steps of:
(c) forming a conformal layer of hardenable material over one or more structures of a master or sub-master manufactured according to claim 1 ; and
(d) separating the conformal layer from the one or more structures of the master or sub-master after hardening of the conformal layer, wherein the hardened conformal layer is the tool.
9. The method of claim 8 , wherein step (c) is preceded by a process of forming a mould-release layer over the one or more structures of the master or sub-master.
10. The method of claim 8 wherein step (c) comprises moulding the hardenable material between the substrate of the master or sub-master and a backing.
11. The method of claim 8 , wherein the hardenable material comprises Polydimethylsiloxane (PDMS).
12. A master manufactured according to the method of claim 1 .
13. A method of fabricating at least one element for a micro-optical device, the method comprising a process of replication employing a tool manufactured according to the method of claim 1 .
14. The method of claim 13 , wherein the at least one element comprises a spacer and/or an optical baffle.
15. A micro-optical device comprising at least one element manufactured according the method of claim 13 .
16. A sub-master manufactured according to the method of claim 7 .
17. A tool manufactured according to the method of claim 8 .