Systems and methods for manufacturing wire grid polarizers
Systems and methods for manufacturing wire grid polarizers include a deposition unit for forming a thin metal film layer on a substrate, a coating unit for applying a photoresist on the thin metal film layer and for baking the photoresist, a stamping unit, including a stamp having a pattern formed thereon, for pressing the stamp onto the photoresist and thereby transferring the pattern of the stamp to the photoresist, and a curing unit for curing the photoresist.
1 . A system for manufacturing a wire grid polarizer, comprising:
a deposition unit for forming a thin metal film layer on a substrate;
a coating unit for applying a photoresist on the thin metal film layer and for baking the photoresist;
a stamping unit, including a stamp on which a pattern is formed, for pressing the stamp onto the photoresist of the substrate and thereby transferring a pattern of the stamp to the photoresist; and,
a curing unit for curing the photoresist.
2 . The system of claim 1 , further comprising:
an etching unit for etching the thin metal film layer; and,
an ashing unit for removing the photoresist.
3 . The system of claim 2 , further comprising:
a loading unit for loading the substrate into the system;
a cleaning unit for cleaning the substrate;
an unloading unit for unloading the substrate from the substrate; and,
a plurality of carrying units for carrying the substrate within the system.
4 . The system of claim 3 , wherein the units are arranged in line with each other in the order of the loading unit, the cleaning unit, the deposition unit, the coating unit, the stamping unit, the curing unit, the etching unit, the ashing unit and the unloading unit, and wherein respective ones of the carrying units are disposed between adjacent pairs of the other units.
5 . The system of claim 1 , wherein the stamping unit further comprises:
a stamping chamber;
a first substrate supporting unit provided in the stamping chamber and configured to support the substrate; and,
a pressing unit for applying pressure to the stamp so as to press the stamp onto the photoresist on the substrate.
6 . The system of claim 5 , wherein the stamp comprises:
a base plate;
first and second magnets having opposite polarities arranged in alternating fashion and embedded in a first surface of the base plate; and,
a plurality of unit stamps electrostatically adhered to the first surface of the base plate.
7 . The system of claim 6 , wherein each unit stamp comprises:
a unit stamp substrate having opposite first and second surfaces; and,
a fine pattern extending in one direction on the first surface of the unit stamp substrate.
8 . The system of claim 7 , wherein the unit stamp further comprises a metal conductive layer on the second surface of the unit stamp substrate.
9 . The system of claim 7 , wherein the unit stamp substrate comprises a silicon wafer or a quartz wafer.
10 . The system of claim 5 , wherein the pressing unit comprises:
a pressing chamber; and,
a gas pressure applying unit for injecting gas into the pressing chamber and applying gas pressure to an interior of the pressing chamber.
11 . The system of claim 10 , wherein the pressing unit further comprises a gas pressure correcting unit for maintaining uniformity of the gas pressure applied to the interior of the pressing chamber.
12 . The system of claim 11 , wherein the gas pressure applying unit comprises:
a gas supply source provided outside of the pressing chamber and configured to supply gas for injection into the pressurizing chamber; and,
gas injection holes formed in a wall of the pressing chamber.
13 . The system of claim 11 , wherein the gas pressure correcting unit comprises a plurality of spring members provided inside the pressurizing chamber.
14 . The system of claim 5 , further comprising a stamp storing chamber for storing waiting stamps.
15 . The system of claims 1 or 5 , wherein the curing unit comprises:
a curing chamber;
a second substrate supporting unit provided in the curing chamber and configured to support the substrate; and,
a curing source unit for curing the photoresist.
16 . The system of claim 15 , wherein the photoresist comprises a UV-curable photoresist or a thermosetting photoresist.
17 . The system of claim 16 , wherein the curing source unit comprises a UV light source or a heater.
18 . The system of claim 15 , wherein the photoresist comprises a hybrid photoresist comprising a mixture of a UV-curable photoresist and a thermosetting photoresist.
19 . The system of claim 18 , wherein:
the stamping unit further comprises a UV light source for curing the UV-curable photoresist of the hybrid photoresist; and,
the curing source unit of the curing unit comprises a heater for curing the thermosetting photoresist of the hybrid photoresist.
20 . The system of claim 19 , wherein the stamping unit further comprises a UV light blocking unit for blocking a part of the UV light radiated from the UV light source.
21 . The system of claim 20 , wherein the UV light blocking unit comprises a metal film.
22 . The system of claim 2 , wherein the etching unit dry-etches the thin metal film layer.
23 . A method for manufacturing a wire grid polarizer, the method comprising:
providing a substrate;
forming a thin metal film layer on the substrate;
applying a photoresist to the thin metal film layer;
baking the substrate to which the photoresist has been applied;
providing a stamp having a pattern thereon;
aligning the stamp with the photoresist of the substrate,
pressing the stamp onto the photoresist of the substrate to transfer the pattern of the stamp to the photoresist;
curing the photoresist;
separating the stamp from the substrate; and,
etching the thin metal film layer of the substrate.
24 . The method of claim 23 , wherein applying a photoresist to the thin metal film layer comprises applying a UV-curable photoresist or a thermosetting photoresist to the thin metal film layer.
25 . The method of claim 24 , wherein curing the photoresist comprises radiating UV light on or applying heat to the photoresist.
26 . The method of claim 23 , wherein providing a stamp comprises providing a plurality of stamps.
27 . A method for manufacturing a wire grid polarizer, the method comprising:
providing a substrate;
forming a thin metal film layer on the substrate;
applying a photoresist to the thin metal film layer;
baking the substrate to which the photoresist is applied;
providing a stamp having a pattern thereon;
aligning the stamp with the photoresist of the substrate;
pressing the stamp on the photoresist of the substrate to transfer the pattern of the stamp to the photoresist;
partially curing the photoresist;
separating the stamp from the substrate;
fully curing the photoresist; and,
etching the thin metal film layer of the substrate.
28 . The method of claim 27 , wherein applying a photoresist to the thin metal film layer comprises applying a hybrid photoresist comprising a mixture of a UV-curable photoresist and a thermosetting photoresist to the thin metal film layer.
29 . The method of claim 28 , wherein partially curing the photoresist comprises irradiating the photoresist with UV light.
30 . The method of claim 29 , wherein:
providing a stamp comprises providing a stamp that is smaller than the substrate; and,
partially curing the photoresist comprises irradiating a region of the substrate on which the stamp has been pressed with UV light.
31 . The method of claim 30 , wherein the aligning of the stamp with the substrate, the pressing of the stamp on the photoresist of the substrate, the partially curing of the photoresist, and the separating of the stamp from the substrate are repeated reiteratively until the pattern of the stamp is transferred throughout the region of the photoresist of the substrate.
32 . The method of claim 28 , wherein fully curing the photoresist comprises applying heat to the photoresist.
33 . The method of claims 23 or 27 , wherein providing a stamp comprises providing a plurality of unit stamps.
34 . The method of claim 33 , wherein providing a plurality of unit stamps comprises:
providing a base plate;
embedded first and second magnets in a first surface of the base plate, the magnets having opposite polarities and being arranged in alternating fashion; and,
electrostatically attaching the plurality of unit stamps to the first surface of the base plate.
35 . The method of claim 33 , wherein providing a plurality of unit stamps comprises:
providing a unit stamp substrate having opposite first and second surfaces;
forming a fine pattern on the surface of the unit stamp substrate;
forming a protective layer over the first surface of the unit stamp and the fine pattern thereon;
cutting the unit stamp substrate; and,
removing the protective layer.
36 . The method of claim 35 , wherein forming a protective layer comprises:
applying a layer of an organic material layer comprising a photoresist or a soluble polymer to the first surface of the unit stamp substrate and the fine pattern thereon; and,
baking the organic material layer.
37 . The method of claim 35 , wherein providing a plurality of unit stamps further comprises forming a metal conductive layer on the second surface of the unit stamp substrate.