Oxidation and Moisture Barrier Layers for Wire Grid Polarizer

Patent metadata

Field	Value
Publication number	US-2016291208-A1
Application number	US-201615078495-A
Country	US
Kind code	A1
Filing date	Mar 23, 2016
Priority date	Apr 3, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A wire grid polarizer (WGP) can have a conformal-coating to protect the WGP from oxidation and/or corrosion. The conformal-coating can include a barrier layer with at least one: of aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide, and zirconium oxide. A method of making a WGP can include applying the barrier layer over ribs of a WGP by vapor deposition.

First claim

What is claimed is:

1 . A wire grid polarizer (WGP) comprising:
a. ribs located over a surface of a transparent substrate, wherein the ribs are elongated and arranged in a substantially parallel array; b. gaps between at least a portion of the ribs; and c. a conformal-coating located over the ribs, wherein:
i. the conformal-coating comprises two layers of different materials, including an oxidation-barrier and a moisture-barrier;
ii. the oxidation-barrier includes aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, a rare earth oxide, or combinations thereof;
iii. the moisture-barrier includes hafnium oxide, zirconium oxide, a rare earth oxide, or combinations thereof;
iv. the oxidation-barrier is located between the moisture-barrier and the ribs; and
v. the oxidation-barrier is distinct from the ribs.

2 . A wire grid polarizer (WGP) comprising:
a. ribs located over a surface of a transparent substrate, wherein the ribs are elongated and arranged in a substantially parallel array; b. gaps between at least a portion of the ribs; and c. a conformal-coating located over the ribs, wherein the conformal-coating includes a barrier layer, the barrier layer including at least one of aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide, zirconium oxide, and a rare earth oxide.

3 . The WGP of claim 2 , wherein the barrier-layer is distinct from the ribs.

4 . The WGP of claim 2 , wherein a material of an exterior surface of the ribs has solubility in water of at least 0.015 grams per liter at 25° C.

5 . The WGP of claim 2 , wherein a material of an exterior surface of the ribs includes germanium.

6 . The WGP of claim 2 , wherein:
a. the barrier-layer comprises two layers of different materials, including an oxidation-barrier and a moisture-barrier; b. the oxidation-barrier includes aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or combinations thereof; c. the moisture-barrier includes hafnium oxide, zirconium oxide, or combinations thereof; and d. the oxidation-barrier is located between the moisture-barrier and the ribs.

7 . The WGP of claim 6 , wherein the oxidation-barrier has a thickness of less than 5 nanometers and the moisture-barrier has a thickness of less than 5 nanometers.

8 . The WGP of claim 2 , wherein:
a. the conformal-coating further comprises a hydrophobic-layer located over the ribs; b. the barrier-layer is located between the hydrophobic-layer and the ribs; and c. the hydrophobic-layer includes a phosphonate conformal-coating, wherein the phosphonate conformal-coating includes:

where:
i. each R 1 independently is a hydrophobic group;
ii. Z is a bond to the ribs; and
iii. R 5 is a chemical element or a group.

9 . The WGP of claim 8 , wherein:
a. R 5 is a phosphonate-reactive-group, R 1 , R 6 , or Z; b. the phosphonate-reactive-group is —Cl, —OR 6 , —OCOR 6 , or —OH; and

10 . The WGP of claim 8 , wherein the hydrophobic-layer urther comprises a silane conformal-coating, wherein the silane conformal-coating includes chemical formula (1), chemical formula (2), or combinations thereof:

where:
a. r is a positive integer;
b. X is a bond to the ribs; and
c. each R 3 is independently a chemical element or a group.

11 . The WGP of claim 10 , wherein:
a. each R 3 is independently selected from the group consisting of: a silane-reactive-group, —H, R 1 , R 6 , and X; b. each silane-reactive-group is independently selected from the group consisting of: —Cl, —OR 6 , —OCOR 6 , —N(R 6 ) 2 , and —OH; and c. each R 6 is independently an alkyl group, an aryl group, or combinations thereof.

12 . The WGP of claim 10 , wherein:
a. each of the ribs includes a rod and a wire; b. the wire is reflective; c. the rod is absorptive; d. X is a bond to the rod; and e. Z is a bond to the wire.

13 . The WGP of claim 10 , wherein:
a. X is —O—Si; and b. Z is —O-Metal, where Metal is a metal atom.

14 . The WGP of claim 2 , wherein:
a. the conformal-coating further comprises a hydrophobic-layer located over the ribs; b. the barrier-layer is located between the hydrophobic-layer and the ribs; and c. the hydrophobic-layer includes a silane conformal-coating, wherein the the silane conformal-coating includes chemical formula (1), chemical formula (2), or combinations thereof:

where:
i. r is a positive integer;
ii. X is a bond to the ribs; and
iii. each R 3 is independently a chemical element or a group.

15 . A method of making a wire-grid polarizer, the method comprising:
a. obtaining an array of ribs located over a surface of a transparent substrate, the ribs being substantially parallel and elongated with gaps between at least a portion of the ribs; and b. applying a barrier layer of a conformal-coating over the ribs by vapor deposition, the barrier layer including at least one of aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide, and zirconium oxide.

16 . The method of claim 15 , further comprising applying a hydrophobic-layer of the conformal-coating by vapor deposition after applying the barrier layer,
wherein applying the hydrophobic-layer includes exposing the WGP to a chemical, the chemical including (R 1 ) i PO(R 4 ) j (R 5 ) k , where:
a. i is 1 or 2, j is 1 or 2, k is 0 or 1, and i+j+k=3;
b. each R 1 is independently a hydrophobic group;
c. R 4 is a phosphonate-reactive-group;
d. each phosphonate-reactive-group is independently selected from: —Cl, —OR 6 , —OCOR 6 , and —OH;
e. each R 6 is independently an alkyl group, an aryl group, or combinations thereof;

17 . The method of claim 16 , wherein the chemical further comprises Si(R 1 ) d (R 2 ) e (R 3 ) g , where:
a. d is 1, 2, or 3, e is 1, 2, or 3, g is 0, 1, or 2, and d+e+g=4; b. R 2 is a silane-reactive-group; and c. each silane-reactive-group is independently selected from: —Cl, —OR 6 , —OCOR 6 , —N(R 6 ) 2 , and —OH.

18 . The method of claim 15 , further comprising applying a hydrophobic-layer of the conformal-coating by vapor deposition after applying the barrier layer, wherein applying the hydrophobic-layer includes exposing the WGP to a chemical, the chemical including Si(R 1 ) d (R 2 ) e (R 3 ) g , where:
a. d is 1, 2, or 3, e is 1, 2, or 3, g is 0, 1, or 2, and d+e+g=4; b. R 2 is a silane-reactive-group; and c. each silane-reactive-group is independently selected from: —Cl, —OR 6 , —OCOR 6 , —N(R 6 ) 2 , and —OH.

19 . The method of claim 15 , wherein applying the barrier layer includes applying the barrier layer by atomic layer deposition at a temperature of at least 300° C.

20 . The method of claim 15 , wherein:
a. applying the barrier layer includes applying an oxidation-barrie hen applying a moisture-barrier; b. the oxidation-barrier includes aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or combinations thereof; and c. the moisture-barrier includes hafnium oxide, zirconium oxide, or combinations thereof.

Assignees

• Moxtek Inc
• Univ Brigham Young

Inventors

• Wangensteen Ted
• Nielson Stew
• Lane Fred
• Linford Matt
• Diwan Anubhav

Classifications

• G02B5/3058 Primary

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

• C23C16/45555

  applied in non-semiconductor technology · CPC title

• C23C16/325

  Silicon carbide · CPC title

• C09D5/084

  Inorganic compounds · CPC title

• C23C16/345

  Silicon nitride · CPC title