We claim:
1. A high throughput method for determining vapor barrier characteristics of films and coatings comprising the steps of:
preparing a vapor sensitive film;
disposing a plurality of coatings andor films onto said vapor sensitive film;
laminating said vapor sensitive film with said coatings andor films onto a transparent backing;
placing said transparent backing with said vapor sensitive film attached thereto and said coatings andor films thereon disposed, into an absorbance measuring instrument;
measuring the absorbance of each of the coatings andor films at spaced locations on said vapor sensitive film;
placing said transparent backing with said vapor sensitive film attached thereto and said coatings andor films thereon disposed, into a vapor chamber wherein the vapor of interest is present;
removing said transparent backing with said vapor sensitive film attached thereto and said coatings andor films thereon disposed from said vapor chamber at various times;
placing said transparent backing with said vapor sensitive film attached thereto and said coatings andor films thereon disposed, into said absorbance measuring instrument and measuring the absorbance of each of coatings andor films locations on said vapor sensitive film again; and
plotting the absorbance of said coatings andor films locations versus time, in order to determine the barrier characteristics of said coatings.
2. The method of claim 1, wherein said plotting of said absorbance of said coatings andor films locations versus time is utilized to determine said vapor’s transmission rate through said coatings andor films.
3. The method of claim 1, wherein areas of calibration are provided upon said vapor sensitive film.
4. The method of claim 1, wherein the deposition of said plurality of coatings andor films onto said vapor sensitive film comprises the steps of:
providing a vapor sensitive film;
utilizing said film as a substrate to form an array of sample receiving wells by overlying an apertured template top over said substrate, with said apertured template top in tight sealing engagement with said substrate;
applying different samples of material in liquid form into said receiving wells;
placing said substrate with said sample receiving wells containing said samples of material in liquid form thereon in a centrifuge;
activating said centrifuge with said sample receiving wells mounted therein to flatten out the sample material in said sample receiving wells, with the centrifugal force acting perpendicular to the bottom of the sample receiving wells;
drying or curing said samples while they are within the centrifuge; and
removing the apertured template to leave said samples exposed on said substrate.
5. The method of claim 1, wherein the preparation of said vapor sensitive film comprises the steps of:
preparing a vapor sensitive composition comprising a predetermined amount of crystal-violet, Nafion , alcohol and water;
providing a substrate of film of predetermined size;
coating a surface of said substrate of film with said vapor sensitive composition; and
allowing the coating of said vapor sensitive composition disposed onto said substrate of film to dry.
6. The method of claim 1, wherein said absorbance measuring instrument is a well plate reader.
7. The method of claim 1, wherein said vapor of interest is water vapor.
8. A multi-layered assembly to test rates of transmission of a vapor through films andor coatings, said multi-layered assembly comprising:
a substrate upon which a vapor sensitive coating is disposed on one side;
a plurality of films andor coatings disposed upon the opposite side of said substrate;
a piece of transparent backing material upon which said substrate is placed with said vapor sensitive coated side of said substrate mounted toward said backing material; and
calibration areas upon said substrate.
9. The multi-layered assembly of 8, wherein said vapor sensitive coating indicates vapor transmission by chromatically changing according to exposure to said vapor.
10. The multi-layered assembly of 8, wherein said vapor is water vapor.
11. The multi-layered assembly of 8, wherein said vapor sensitive coating is comprised of:
a predetermined volume of a solution of crystal violet in methanol having a predetermined concentration;
a predetermined volume of Nafion OR solution; and,
a predetermined volume of water.
12. The multi-layered assembly of 8, wherein said barrier coatings are disposed onto said substrate by utilizing a multi-well apparatus.
13. The barrier coatings of claim 12, wherein said barrier coatings are disposed onto said film by utilizing said multi-well apparatus and a centrifuge.
14. The centrifuge of claim 13, wherein said centrifuge’s axis of rotation is horizontal.
15. The multi-well apparatus of claim 12, wherein said multi-well apparatus is comprised of silicone.
16. The multi-layered assembly of 8, wherein said piece of transparent backing material has high vapor barrier properties.
17. The transparent backing material of claim 16, wherein said transparent backing material is glass.
18. The multi-layered assembly of 8; wherein said areas of calibration are comprised of materials having known vapor transmission rates.
19. The multi-layered assembly of 9, wherein said chromatic change of said vapor sensitive coating is measured by a multi-well plate reader, said multi-well plate reader utilizing absorbance.
20. A coatable water vapor sensitive composition for determining water vapor transmission rates of material coatings, said water vapor sensitive composition comprising:
a predetermined volume of crystal violet in methanol having a predetermined molarity;
a predetermined volume of Nafion ( solution; and,
a predetermined volume of water.
21. A method for producing a water vapor sensor, comprising the steps of:
preparing a water vapor sensitive composition comprising predetermined amounts of crystal-violet, Nafion (, alcohol and water;
moistening a flat surface with water;
placing a substrate onto said moistened, flat surface and flattening said substrate;
coating an exposed surface of said substrate with said water vapor sensitive composition to form a coating; and
allowing the coating of said water vapor sensitive composition disposed onto said substrate to dry, whereby a water vapor sensor is provided.
22. The method of claim 21, wherein said water vapor sensitive composition is coated upon said substrate utilizing a Byrd bar.
23. The method of claim 21, wherein said substrate is a film comprised of polyethylene terephthalate.
24. A water vapor sensor comprising a substrate and a water vapor sensitive composition coated one side of said substrate, wherein said substrate is flexible and said water vapor sensitive composition is comprised of:
a predetermined volume of crystal violet in methanol having a predetermined molarity;
a predetermined volume of Nafion ( solution; and,
a predetermined volume of water.
25. The water vapor sensor of claim 24, wherein said flexible substrate is comprised of polyethylene terephthalate.
26. A high throughput method for determining vapor barrier characteristics of films and coatings comprising the steps of:
preparing a vapor sensitive film;
disposing an array of coatings andor films in overlying relationship to said vapor sensitive film;
laminating said vapor sensitive film with said coatings andor films onto a transparent backing;
placing said transparent backing with said vapor sensitive film attached thereto and said coatings andor films thereon disposed, into an absorbance measuring instrument;
measuring the absorbance of each of the coatings andor films at spaced locations on said vapor sensitive film;
exposing said transparent backing with said vapor sensitive film attached thereto and said coatings andor films thereon disposed to the vapor of interest; and
following a predetermined period of time of exposure to said vapor, placing said transparent backing with said vapor sensitive film attached thereto and said coatings andor films thereon disposed, into an absorbance measuring instrument and measuring the absorbance of each of coatings andor films of said array at spaced locations on said vapor sensitive film.
27. The method of claim 26 wherein areas of calibration are provided upon said vapor sensitive film.
28. The method of claim 26, wherein the deposition of said array of coatings andor films onto said vapor sensitive film comprises the steps of:
providing a vapor sensitive film;
utilizing said film as a substrate to form an array of sample receiving wells by overlying an apertured template top over said substrate, with said apertured template top in tight sealing engagement with said substrate;
applying different samples of material in liquid form into said receiving wells;
placing said substrate with said sample receiving wells containing said samples of material in liquid form thereon in a centrifuge;
activating said centrifuge with said sample receiving wells mounted therein to flatten out the sample material in said sample receiving wells, with the centrifugal force acting perpendicular to the bottom of the sample receiving wells;
drying said samples while they are within the centrifuge; and
removing the apertured template to leave said samples exposed on said substrate.
29. A method for determining vapor barrier characteristics of films and coatings comprising the steps of:
preparing a vapor sensitive film;
disposing a coating or film to be tested in overlying relationship to said vapor sensitive film;
laminating said vapor sensitive film and said coating or film onto a substrate;
exposing said substrate with said vapor sensitive film, and said coating or film disposed thereon, to the vapor of interest; and
following a predetermined period of time of exposure to said vapor, placing said substrate with said vapor sensitive film attached thereto and said coating or film disposed thereon, into an optical measuring instrument and measuring the optical state of said vapor sensitive film.
30. The method for determining vapor barrier characteristics of films and coatings of claim 29, wherein said optical measuring instrument measures absorbance.
31. The method for determining vapor barrier characteristics of films and coatings of claim 29, wherein said vapor sensitive film is comprised of a light absorbing organic dye or organic dye composition.
32. The method for determining vapor barrier characteristics of films and coatings of claim 31, wherein said organic dye or organic dye composition is comprised of crystal violet and Nafion .
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A method for fabricating a longitudinally biased bottom spin valve GMR read sensor having a lead overlay configuration and narrow trackwidth comprising:
providing a substrate;
forming on the substrate a bottom spin valve stack, said stack having a barrier layer capped by a bilayer formed of an upper layer and a lower layer and said stack being bounded laterally by edges;
annealing said stack with a first anneal;
forming a longitudinal bias layer of permanent magnetic material (hard bias layer) contiguous to said stack edges;
forming a second capping layer on said bias layer;
forming a blanket conducting lead overlay layer (LOL) over said stack and capped bias layer;
annealing said LOL blanketed stack and bias layer with a second anneal;
forming an opening within a central portion of said lead overlay layer (LOL), the lateral extension of said opening defining a physical trackwidth and the opening extending vertically through the LOL and the upper layer of the capping bilayer and reaching at least to the upper surface of the lower layer of said capping bilayer but not reaching its lower surface and the remaining thickness of said lower layer being oxidized thereby to form a specularly reflecting layer.
2. The method of claim 1 wherein the LOL conducting layer is a bilayer comprising an Au layer on which is formed a Ta layer.
3. The method of claim 2 wherein the Au layer is formed to a thickness of between approximately 250 and 450 angstroms and where the Ta layer is formed to a thickness of between approximately 100 and 150 angstroms.
4. The method of claim 1 wherein said stack formation comprises:
a seed layer;
an antiferromagnetic pinning layer formed on said seed layer;
a synthetic antiferromagnetic pinned layer formed on said pinning layer;
a non-magnetic spacer layer formed on said pinned layer;
a ferromagnetic free layer formed on said spacer layer;
a barrier layer formed on said free layer;
a capping bilayer formed on said barrier layer, said bilayer having an upper layer and a lower layer.
5. The method of claim 4 wherein the upper layer of the capping bilayer protects the lower layer of the capping bilayer from oxidation during sensor annealing processes.
6. The method of claim 4 wherein the capping bilayer comprises a lower layer of Ta on which is formed an upper layer of Au.
7. The method of claim 6 wherein the layer of Ta is formed to a thickness of between approximately 20 and 40 angstroms and wherein the Au layer is formed to a thickness of between approximately 75 angstroms and 150 angstroms.
8. The method of claim 6 wherein the barrier layer protects the free layer from Au diffusion during sensor annealing processes and oxidation during sensor annealing processes and etching processes.
9. The method of claim 7 wherein the barrier layer is a layer of Ru formed to between approximately 5 and 15 angstroms, with approximately 5 angstroms being preferred.
10. The method of claim 4 wherein the ferromagnetic free layer is a bilayer comprising a layer of CoFe, on which is formed a layer of NiFe.
11. The method of claim 9 wherein the CoFe layer is formed to a thickness of between approximately 5 and 15 angstroms and the NiFe layer is formed to a thickness of between approximately 15 and 30 angstroms.
12. The method of claim 1 wherein the first anneal is to set the magnetization of the stack pinned layer and the anneal is carried out in a transverse magnetic field of approximately 10 kOe, at a temperature of approximately 280 C. and for a time of approximately 5 hours.
13. The method of claim 1 wherein the second anneal is to set the magnetization of the stack free layer and the anneal is carried out in a longitudinal magnetic field of approximately 250 Oe, at a temperature of approximately 250 C. and for a time of approximately 1 hour.
14. The method of claim 1 wherein the bias layer is a layer of CoPtCr formed to a thickness of between approximately 200 and 400 angstroms.
15. The method of claim 1 wherein the second capping layer is a bilayer comprising a layer of Ta formed to a thickness of between approximately 10 and 30 angstroms on which is formed a layer of Au to a thickness of between approximately 100 and 150 angstroms.
16. The method of claim 1 wherein the opening within the central portion of the LOL is produced by a sequence of two reactive ion etch (RIE) processes, said processes further comprising:
forming an etch resistant coating on the upper surface of the LOL layer;
forming an opening in said coating, the lateral dimension of said opening being the width of a desired sensor trackwidth and said opening exposing the upper surface of the Ta layer of the LOL layer;
applying a CF4 RIE to the upper surface of said Ta layer until the entire thickness of the Ta layer is removed, exposing, thereby, a portion of the Au layer beneath said Ta layer;
applying an ArO2 plasma RIE to the Au layer, using the opening in the Ta layer as a mask;
removing the full thickness of the Au layer with said plasma RIE and oxidizing the Ta layer beneath said Au layer.
17. The method of claim 16 wherein the opening in said coating is between approximately 0.1 and 0.2 microns in width, with an opening less than 0.15 microns being preferred.
18. The method of claim 4 wherein the seed layer is a layer of NiCr formed to a thickness of between approximately 50 and 60 angstroms.
19. The method of claim 4 wherein the antiferromagnetic pinning layer is a layer of material chosen from the group consisting of MnPt, IrMn and IrMnPt.
20. The method of claim 4 wherein the antiferromagnetic pinning layer is a layer of MnPt formed to a thickness of between approximately 100 and 150 angstroms.
21. The method of claim 4 wherein the synthetic antiferromagnetic pinned layer is formed by a method further comprising:
forming a first ferromagnetic layer on said pinning layer;
forming a non-magnetic antiferromagnetically coupling layer on said first ferromagnetic layer;
forming a second ferromagnetic layer on said coupling layer.
22. The method of claim 21 wherein the first and second ferromagnetic layers are chosen from the group of ferromagnetic materials consisting of CoFe, NiFe and CoFeNi.
23. The method of claim 22 wherein the first ferromagnetic layer is a layer of CoFe formed to a thickness of between approximately 13 and 20 angstroms, and the second ferromagnetic layer is a layer of CoFe formed to a thickness of between approximately 15 and 25 angstroms.
24. The method of claim 22 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Ru formed to a thickness of between approximately 7 and 8 angstroms.
25. The method of claim 4 wherein the non-magnetic spacer layer is a layer of Cu formed to a thickness of between approximately 16 and 20 angstroms.
26. A longitudinally biased bottom spin valve GMR read sensor having a lead overlay configuration and narrow trackwidth comprising:
a substrate;
a bottom spin valve stack formed on the substrate, said stack having a barrier layer capped by a bilayer formed of an upper layer and a lower layer and said stack being bounded laterally by edges;
a longitudinal bias layer of permanent magnetic material (hard bias layer) formed contiguous to said stack edges;
a second capping layer formed on said bias layer;
a blanket conducting lead overlay layer (LOL) formed over said stack and bias layer;
an opening formed within a central portion of said lead overlay layer (LOL), the lateral extension of said opening defining a physical trackwidth and the opening extending vertically through the LOL and the upper layer of the capping bilayer and reaching at least to the upper surface of the lower layer of said capping bilayer but not reaching its lower surface and the remaining thickness of said lower layer being oxidized thereby to form a specularly reflecting layer; and
the sensor so formed having its pinned layer transversely magnetized and its free layer and its bias layer longitudinally magnetized.
27. The sensor of claim 26 wherein the LOL conducting layer is a bilayer comprising an Au layer on which is formed a Ta layer.
28. The sensor of claim 27 wherein the Au layer is formed to a thickness of between approximately 250 and 450 angstroms and where the Ta layer is formed to a thickness of between approximately 100 and 150 angstroms.
29. The sensor of claim 27 wherein said stack formation comprises:
a seed layer;
an antiferromagnetic pinning layer formed on said seed layer;
a synthetic antiferromagnetic pinned layer formed on said pinning layer;
a non-magnetic spacer layer formed on said pinned layer;
a ferromagnetic free layer formed on said spacer layer;
a barrier layer formed on said free layer;
a capping bilayer formed on said barrier layer, said bilayer having an upper layer and a lower layer.
30. The sensor of claim 26 wherein the first capping layer is a bilayer comprising a layer of Ta on which is formed a layer of Au.
31. The sensor of claim 29 wherein the Au layer protects the Ta layer from oxidation during sensor annealing processes.
32. The sensor of claim 29 wherein the layer of Ta is formed to a thickness of between approximately 20 and 40 angstroms and wherein the Au layer is formed to a thickness of between approximately 75 and 150 angstroms.
33. The sensor of claim 30 wherein the barrier layer protects the free layer from Au diffusion during sensor annealing processes and oxidation during sensor annealing processes and etching processes.
34. The sensor of claim 33 wherein the barrier layer is a layer of Ru formed to a thickness of between approximately 5 and 15 angstroms.
35. The sensor of claim 29 wherein the free layer is a bilayer comprising a layer of CoFe, on which is formed a layer of NiFe.
36. The sensor of claim 35 wherein the CoFe layer is formed to a thickness of between approximately 5 and 15 angstroms and the NiFe layer is formed to a thickness of between approximately 15 and 25 angstroms.
37. The sensor of claim 26 wherein the opening within the LOL layer is between approximately 0.1 and 0.2 microns.
38. The sensor of claim 29 wherein the synthetic antiferromagnetic pinned layer further comprises:
a first ferromagnetic layer;
a non-magnetic antiferromagnetically coupling layer formed on said first ferromagnetic layer;
a second ferromagnetic layer formed on said coupling layer.
39. The sensor of claim 38 wherein the first ferromagnetic layer is a layer of CoFe formed to a thickness of between approximately 13 and 20 angstroms and the second ferromagnetic layer is a layer of CoFe formed to a thickness of between approximately 15 and 25 angstroms.
40. The sensor of claim 38 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Ru formed to a thickness of between approximately 7 and 8 angstroms.
41. The sensor of claim 29 wherein the non-magnetic spacer layer is a layer of Cu formed to a thickness of between approximately 16 and 20 angstroms.
42. The sensor of claim 27 wherein the bias layer is a layer of CoPtCr formed to a thickness of between approximately 200 and 400 angstroms.
43. The sensor of claim 27 wherein the second capping layer is a bilayer comprising a layer of Ta formed to a thickness of between approximately 10 and 30 angstroms on which is formed a layer of Au formed to a thickness of between approximately 100 and 150 angstroms.