Wire Grid Polarizer with Water-Soluble Materials

1 . A wire grid polarizer (WGP) comprising:

a. ribs located over a surface of a transparent substrate, wherein:

i. the ribs are elongated and arranged in a substantially parallel array, and

ii. a material of an exterior surface of the ribs has a solubility in water of at least 0.015 grams per liter at 25° C.;

b. gaps between at least a portion of the ribs; and

c. a conformal-coating located over the ribs, the conformal-coating including a barrier-layer, a hydrophobic-layer, or both, wherein:

i. the barrier-layer includes at least one of aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, hafnium oxide, and zirconium oxide; and

ii. the hydrophobic-layer includes chemical formula (1), chemical formula (2), chemical formula (3), or combinations thereof:

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

2 . A wire grid polarizer (WGP) comprising:

a. ribs located over a surface of a transparent substrate, wherein:

i. the ribs are elongated and arranged in a substantially parallel array, and

ii. a material of an exterior surface of the ribs has a solubility in water of at least 0.015 grams per liter at 25° C.;

b. gaps between at least a portion of the ribs; and

c. a conformal-coating located over the ribs.

3 . The WGP of claim 2 , wherein the conformal-coating includes hafnium oxide, zirconium oxide, aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or combinations thereof.

4 . The WGP of claim 2 , wherein:

a. the conformal-coating 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-ba rier and the ribs.

5 . The WGP of claim 2 , wherein the conformal-coating includes a phosphonate conformal-coating, the phosphonate conformal-coating including:

where:

a. each R 1 independently is a hydrophobic group;

b. Z is a bond to the ribs;

c. R 5 is a chemical element or a group.

6 . The WGP of claim 5 , wherein:

a. R 5 is a phosphonate-reactive-group, R 1 , R 6 , or Z;

b. the phosphonate-reactive-group is —Cl, —R 6 , —OCOR 6 , or —OH; and

c. each R 6 is independently an alkyl group, an aryl group, or combinations thereof.

7 . The WGP of claim 2 , wherein the conformal-coating includes a silane conformal-coating, the silane conformal-coating including chemical formula (1), chemical formula (2), or combinations thereof:

where:

a. r is a positive integer;

b. each R 1 independently is a hydrophobic group;

c. X is a bond to the ribs;

d. each R 3 is independently a chemical element or a group.

8 . The WGP of claim 7 , 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.

9 . The WGP of claim 7 , wherein:

a. the conformal-coating further comprises a phosphonate conformal-coating, the phosphonate conformal-coating including:

where:

i. Z is a bond to the ribs; and

ii. R 5 is a chemical element or a group,

b. each of the ribs includes a rod and a wire;

c. the wire is reflective;

d. the rod is absorptive;

e. X is a bond to the rod; and

f. Z is a bond to the wire.

10 . The WGP of claim 2 , wherein:

a. the conformal-coating comprises at least three layers of different materials, including an oxidation-barrier, a moisture-barrier, and a hydrophobic-layer;

b. the oxidation-barrier is located between the moisture-barrier and the ribs;

c. the moisture-barrier is located between the hydrophobic-layer and the oxidation-barrier;

d. the oxidation-barrier includes aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or combinations thereof;

e. the moisture-barrier includes hafnium oxide, zirconium oxide, or combinations thereof; and

f. the hydrophobic-layer includes chemical formula (1), chemical formula (2), chemical formula (3), or combinations thereof:

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

11 . The WGP of claim 10 , wherein the hydrophobic group includes a carbon chain.

12 . The WGP of claim 10 , wherein the hydrophobic group includes CF 3 (CF 2 ) n (CH 2 ) m , where n and m are integers within the boundaries of: 0≦n≦20 and 0≦m≦5.

13 . The WGP of claim 10 , wherein the hydrophobic group includes CF 3 (CF 2 ) n (CH 2 ) m , where n and m are integers within the boundaries of: 4≦n≦10 and 2≦m≦5.

14 . The WGP of claim 2 , wherein the material of the exterior of the ribs includes germanium.

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 a material of an exterior of the ribs has a solubility in water of at least 0.015 grams per liter at 25° C.; and

b. using an anhydrous method to apply a conformal-coating over the ribs.

16 . The method of claim 15 , wherein using the anhydrous method to apply the conformal-coating includes applying a barrier layer 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.

17 . The method of claim 15 , wherein using the anhydrous method to apply the conformal-coating includes applying a hydrophobic-layer by vapor deposition, 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 , (R 1 ) i PO(R 4 ) j (R 5 ) k , or combinations thereof, 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. i is 1 or 2, j is 1 or 2, k is 0 or 1, and i+j+k=3;

c. each R 1 is independently a hydrophobic group;

d. R 2 is a silane-reactive-group; and

e. each silane-reactive-group is independently selected from: —Cl, —OR 6 , —OCOR 6 , —N(R 6 ) 2 , and —OH,

f. R 4 is a phosphonate-reactive-group;

g. each phosphonate-reactive-group is independently selected from: —Cl, —OR 6 , —OCOR 6 , and —OH; and

h. each R 6 is independently an alkyl group, an aryl group, or combinations thereof.

18 . The method of claim 15 , wherein the anhydrous nne hod includes vapor-deposition.

19 . The method of claim 16 , wherein the material of the exterior of the ribs includes germanium.

20 . The method of claim 16 , wherein:

a. each of the ribs include a rod and a wire;

b. the wire is reflective; and

c. the rod includes at least 50 mass percent germanium.