Durable, high performance wire grid polarizer having barrier layer

Patent metadata

Field	Value
Publication number	US-11714221-B2
Application number	US-202117220370-A
Country	US
Kind code	B2
Filing date	Apr 1, 2021
Priority date	Aug 16, 2016
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

A method for making a wire grid polarizer (WGP) can provide WGPs with high temperature resistance, robust wires, oxidation resistance, and corrosion protection. In one embodiment, the method can comprise: (a) providing an array of wires on a bottom protection layer; (b) applying a top protection layer on the wires, spanning channels between wires; then (c) applying an upper barrier-layer on the top protection layer and into the channels through permeable junctions in the top protection layer. In a variation of this embodiment, the method can further comprise applying a lower barrier-layer before applying the top protection layer. In another variation, the bottom protection layer and the top protection layer can include aluminum oxide. In another embodiment, the method can comprise applying on the WGP an amino phosphonate then a hydrophobic chemical.

First claim

What is claimed is:

1. A wire grid polarizer (WGP) comprising:
an array of wires sandwiched between a bottom protection layer and a top protection layer;
channels between adjacent wires, the channels being air filled;
the top protection layer spans the channels; forms a continuous layer with the top protection layer on adjacent wires touching; and has permeable junctions, including a permeable junction between the top protection layer on adjacent wires;
a lower barrier-layer: located on the wires and the bottom protection layer inside of the channels in a conformal layer; not located between the bottom protection layer and the wires; not located at an outermost surface of the top protection layer; and including a metal oxide; and
an upper barrier-layer: located on surfaces of the channels as an outermost layer of solid material; located on an outermost surface of the top protection layer as an outermost layer of solid material; and including a hydrophobic chemical; and
the upper barrier-layer further comprises an amino phosphonate and the amino phosphonate is a lower layer in the upper barrier-layer.

2. A wire grid polarizer (WGP) comprising:
an array of wires sandwiched between a bottom protection layer and a top protection layer;
channels between adjacent wires, the channels being air filled;
the top protection layer spans the channels; forms a continuous layer with the top protection layer on adjacent wires touching; and has permeable junctions, including a permeable junction between the top protection layer on adjacent wires;
a lower barrier-layer: located on the wires and the bottom protection layer inside of the channels in a conformal layer; not located between the bottom protection layer and the wires; not located at an outermost surface of the top protection layer; and including a metal oxide;
an upper barrier-layer: located on surfaces of the channels as an outermost layer of solid material; located on an outermost surface of the top protection layer as an outermost layer of solid material; and including a hydrophobic chemical;
each wire of the array of wires includes a proximal end closest to the bottom protection layer and a distal end closest to the top protection layer;
each channel extends beyond the proximal end into the bottom protection layer for a depth of between 10 nm and 200 nm;
each channel extends beyond the distal end into the top protection layer for a depth of between 10 nm and 200 nm; and
a ratio of the depth into the bottom protection layer to the depth into the top protection layer is between 0.5 and 2.

3. The WGP of claim 2 , wherein the upper barrier-layer is an outermost layer of solid material.

4. The WGP of claim 2 , wherein:
the hydrophobic chemical includes a silane chemical, a phosphonate chemical, or both;
the silane chemical has chemical formula (1), chemical formula (2), or combinations thereof, and the phosphonate chemical has chemical formula (3):

where r is a positive integer, each R 1 independently is a hydrophobic group, each X and Z is a bond to the wires, and each R 3 and R 5 is independently a chemical element or a group.

5. The WGP of claim 2 , wherein the upper barrier-layer further comprises an amino phosphonate, the amino phosphonate is a lower layer in the conformal coating, and the amino phosphonate is sandwiched between the hydrophobic chemical and the wires.

6. The WGP of claim 5 , wherein the amino phosphonate is nitrilotri(methylphosphonic acid).

7. A wire grid polarizer (WGP) comprising:
an array of wires sandwiched between a bottom protection layer and a top protection layer;
channels between adjacent wires, the channels being air filled;
the top protection layer spans the channels; forms a continuous layer with the top protection layer on adjacent wires touching; and has permeable junctions, including a permeable junction between the top protection layer on adjacent wires;
a lower barrier-layer: located on the wires and the bottom protection layer inside of the channels in a conformal layer; not located between the bottom protection layer and the wires; not located at an outermost surface of the top protection layer; and including a metal oxide;
an upper barrier-layer: located on surfaces of the channels as an outermost layer of solid material; located on an outermost surface of the top protection layer as an outermost layer of solid material; and including a hydrophobic chemical;
the lower barrier-layer comprises two layers of different materials, including an oxidation-barrier and a moisture-barrier, with the oxidation-barrier between the moisture-barrier and the wires;
the oxidation-barrier is distinct from the wires and includes aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, a rare earth oxide, or combinations thereof; and
the moisture-barrier includes hafnium oxide, zirconium oxide, a rare earth oxide different from the rare earth oxide of the oxidation-barrier, or combinations thereof.

8. The WGP of claim 7 , wherein:
the hydrophobic chemical includes a silane chemical, a phosphonate chemical, or both;
the silane chemical has chemical formula (1), chemical formula (2), or combinations thereof, and the phosphonate chemical has chemical formula (3):

where r is a positive integer, each R 1 independently is a hydrophobic group, each X and Z is a bond to the wires, and each R 3 and R 5 is independently a chemical element or a group.

9. The WGP of claim 7 , wherein the hydrophobic chemical includes CF 3 (CF 2 ) n (CH 2 ) m , where n≥1 and n≤8, and m≥1 and m≤4.

10. The WGP of claim 7 , wherein each of the wires includes a reflective layer sandwiched between a lower absorptive layer and an upper absorptive layer.

11. The WGP of claim 7 , wherein the upper barrier-layer further comprises an amino phosphonate.

12. The WGP of claim 11 , wherein the amino phosphonate comprises nitrilotri(methylphosphonic acid) (ATMP); and wherein a mass fraction of ATMP/hydrophobic chemical is ≥0.1 and ≤10.

13. A wire grid polarizer (WGP) comprising:
an array of wires sandwiched between a bottom protection layer and a top protection layer;
channels between adjacent wires;
the bottom protection layer and the top protection layer each comprise aluminum oxide;
a lower barrier-layer located at a surface of the wires in the channels, an exposed surface of the bottom protection layer in the channels, and between each wire and the top protection layer;
the lower barrier-layer comprises two layers of different materials, including an oxidation-barrier and a moisture-barrier, the oxidation-barrier being between the moisture-barrier and the wires;
the oxidation-barrier is distinct from the wires and includes aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, a rare earth oxide, or combinations thereof; and
the moisture-barrier includes hafnium oxide, zirconium oxide, a rare earth oxide different from the rare earth oxide of the oxidation-barrier, or combinations thereof.

14. The WGP of claim 13 , wherein:
the channels are air filled;
each wire of the array of wires includes a proximal end closest to the bottom protection layer and a distal end closest to the top protection layer;
each channel extends beyond the proximal end into the bottom protection layer for a depth of between 10 nm and 200 nm;
each channel extends beyond the distal end into the top protection lay

Assignees

• Moxtek Inc

Inventors

• Nielson R Stewart
• George Matthew C
• Ogden Shaun
• Bowers Brian

Classifications

• G02B5/3058 Primary

  comprising electrically conductive elements, e.g. wire grids, conductive particles · CPC title

• C23C14/0036

  Reactive sputtering · CPC title

• C23C14/081 Primary

  of aluminium, magnesium or beryllium · CPC title

• C23C14/12

  Organic material · CPC title

• C23C14/34

  Sputtering · CPC title