1. A method for producing an optically variable device (OVD), the method comprising:
adhering an optically-transmissive polymeric layer with a first layer of partially reflective, partially absorptive, and partially transmissive material; and
adhering a second layer of partially reflective, partially absorptive, and partially transmissive material to said optically-transmissive polymeric layer to form a multi-layer etalon structure in which, across an entire area of the OVD, said optically-transmissive polymeric layer is an etalon spacer layer between said first and second layers,
wherein said optically-transmissive polymeric layer is formed in vacuum by depositing a monomeric layer and radiation curing said monomeric layer within 2 seconds after its deposition and under conditions that result in (i) a maximum variation in thickness thereof not exceeding 5 percent across the entire surface area of the OVD and (ii) minimization of differential re-evaporation of said monomeric layer.
2. A method according to claim 1, further comprising adhering said OVD onto a flexible substrate.
3. A method according to claim 2, further comprising adhering a leveling layer onto said flexible substrate.
4. A method according to claim 2, wherein the adhering said OVD onto a flexible substrate includes adhering said OVD onto a flexible substrate that has a haze factor of less than 5 percent.
5. A method according to claim 2, wherein the adhering said OVD onto a flexible substrate includes adhering said OVD onto a flexible substrate that has a haze factor of less than 1 percent.
6. A method according to claim 2, wherein the adhering said OVD onto a flexible substrate includes adhering said OVD onto a flexible substrate that has a gloss value of greater than 90 percent.
7. A method according to claim 2, wherein the adhering said OVD onto a flexible substrate includes adhering said OVD onto a flexible substrate that has a gloss value of greater than 95 percent.
8. A method according to claim 1, wherein said first layer of partially reflective, partially absorptive, and partially transmissive material has surface emissivity value that does not vary by more than +\u22120.1 across said entire area.
9. A method according to claim 1, wherein said optically-transmissive polymeric layer has a refractive index smaller than 1.6 and wherein no spatial variation in color-shifting, which is caused by non-uniformity of a thickness profile of said polymeric layer, is visually perceivable with a naked eye.
10. A method according to claim 1, further comprising incorporating said OVD into an item selected form the group consisting of a banknote, a security label, and an article of value.
11. A method according to claim 1, further comprising selecting a thickness of said optically-transmissive polymeric layer to produce, as a function of angle of incidence of ambient light onto the OVD, a visually-perceivable shift of color of said ambient light reflected by the OVD between green and silver.
12. A method according to claim 1, further comprising selecting a thickness of said optically-transmissive polymeric layer to produce, as a function of angle of incidence of ambient light onto the OVD, a visually-perceivable shift of color of said ambient light reflected by the OVD between magenta and gold.
13. A method according to claim 1, further comprising selecting a thickness of said optically-transmissive polymeric layer to produce, as a function of angle of incidence of ambient light onto the OVD, a visually-perceivable shift of color of said ambient light reflected by the OVD between blue and red.
14. A method according to claim 1, further comprising selecting a thickness of said optically-transmissive polymeric layer to produce, as a function of angle of incidence of ambient light onto the OVD, a visually-perceivable shift of color of said ambient light reflected by the OVD between green and blue.
15. A method according to claim 1, further comprising selecting a thickness of said optically-transmissive polymeric layer to produce, as a function of angle of incidence of ambient light onto the OVD, a visually-perceivable shift of color of said ambient light reflected by the OVD between gold and green.
16. A method according to claim 1, further comprising selecting a thickness of said optically-transmissive polymeric layer to produce, as a function of angle of incidence of ambient light onto the OVD, a visually-perceivable shift of color of said ambient light reflected by the OVD between magenta and green.
17. A method for producing an optically variable device (OVD), the method comprising:
adhering an optically-transmissive polymeric layer with a first layer of partially reflective, partially absorptive, and partially transmissive material, and
adhering a second layer of partially reflective, partially absorptive, and partially transmissive material to said optically-transmissive polymeric layer to form a multi-layer etalon structure in which, across an entire area of the OVD, said optically-transmissive polymeric layer is an etalon spacer layer between said first and second layers,
wherein said optically-transmissive polymeric layer is formed in vacuum by depositing a monomeric layer and radiation curing said monomeric layer within 2 seconds after its deposition and under conditions that result in (i) a maximum variation in thickness thereof not exceeding 5 percent across the entire surface area of the OVD, and (ii) minimization of differential re-evaporation of said monomeric layer, and
wherein said OVD is adhered onto a substrate that has a gloss value greater than 90%.
18. A method according to claim 17, wherein said substrate has a haze factor of less than 5 percent, and wherein the OVD does not exhibit spatial variations in color-shifting that are caused by non-uniformity of a thickness profile of said polymeric layer and that are visually perceivable with a naked eye.
19. A method for producing an optically variable device (OVD), the method comprising:
adhering an optically-transmissive polymeric layer with a first layer of partially reflective, partially absorptive, and partially transmissive material, wherein the first layer has an emissivity variation less than +\u22120.1 across the first layer,
adhering a second layer of partially reflective, partially absorptive, and partially transmissive material to said optically-transmissive polymeric layer to form a multi-layer etalon structure in which, across an entire area of the OVD, said optically-transmissive polymeric layer is an etalon spacer layer between said first and second layers,
wherein said optically-transmissive polymeric layer is formed in vacuum by depositing a monomeric layer that is radiation cured within 2 seconds after its deposition and under conditions that ensure a maximum variation in thickness thereof not exceeding 5 percent across an entire surface area of the OVD.
20. A method according to claim 19, wherein said optically-transmissive polymeric layer is formed in vacuum by depositing a monomeric layer under conditions that result in minimization of differential re-evaporation of said monomeric layer.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A process for the removal of contaminants from a substrate surface requiring precision cleaning, comprising the steps of: a) applying a high vapor pressure liquid to the substrate surface; and b) cryogenically cleaning the surface of the substrate; to remove contaminants from the substrate surface.
2. The process of claim 1 wherein steps a) and b) are carried out simultaneously.
3. The process of claim 1 wherein the high vapor pressure liquid has a vapor pressure greater than about 5 kPa at 25 C., and a freezing point below about 50 C.
4. The process of claim 3 wherein the high vapor pressure liquid has a dipole moment of greater than about 1.5 D.
5. The process of claim 1 wherein the high vapor pressure liquid is selected from the group consisting of ethanol, acetone, ethanol-acetone mixtures, isopropyl alcohol, methanol, methyl formate, methyl iodide, ethyl bromide, acetonitrile, ethyl chloride, pyrrolidine, tetrahydrofuran and mixtures thereof.
6. The process of claim 1 wherein the substrate is a semiconductor or dielectric film.
7. The process of claim 1 wherein the high vapor pressure liquid remains on the surface in a layer of at least 5 for between about 1 to 10 minutes prior to the initiation of cryogenic cleaning.
8. The process of claim 1 wherein the substrate may be rotated during the spraying of the high vapor pressure liquid on the substrate surface.
9. The process of claim 1 wherein the contaminants are less than 0.76 m in size.
10. The process of claim 1 wherein the high vapor pressure liquid removes bulk water from the surface.
11. A process of cleaning the surface of a semiconductor or dielectric film comprising the steps of: a) spraying a high vapor pressure liquid onto the surface; b) spraying a liquid CO2 stream through a nozzle to form a gaseous CO2 stream having solid CO2 particles, and c) directing said stream at the surface; thereby removing contaminants from the surface.
12. The process of claim 11 wherein the high vapor pressure liquid is sprayed as a mist from a nozzle placed behind a CO2 nozzle and is sprayed simultaneously with the CO2.
13. The process of claim 11 wherein the high vapor pressure liquid has a vapor pressure greater than about 5 kPa at 25 C., and a freezing point below about 50 C.
14. The process of claim 13 wherein the high vapor pressure liquid has a dipole moment greater than about 1.5 D.
15. The process of claim 11 wherein the high vapor pressure liquid removes bulk water from the surface.
16. The process of claim 11 wherein the high vapor pressure liquid is selected from the group consisting of ethanol, acetone, isopropyl alcohol, methanol, methyl formate, methyl iodide, ethyl bromide, acetonitrile, ethyl chloride, pyrrolidine, tetrahydrofuran, and mixtures thereof.
17. The process of claim 1 1 where the gaseous CO2 stream is directed at the surface at an angle of between 30-60.
18. The process of claim 11 wherein the high vapor pressure liquid is sprayed onto the surface as thin layers of at least 5 .
19. The process of claim 11 wherein the particles are less than about 0.76 m in size.
20. A process for cleaning a surface of a semiconductor or dielectric film to remove contaminants having a particle size of about 0.76 m or less, comprising the steps of:
a) spraying a high vapor pressure liquid, having a vapor pressure of 5kPa or greater and a freezing point of about 50 C. or less, in thin layers onto the surface; b) leaving the liquid on the surface for at least one minute, prior to the initiation of cryogenic cleaning of the surface.
21. A process for cleaning a surface of a semiconductor or dielectric film to remove contaminants having a particle size of about 0.76 m or less, comprising the steps of:
a) spraying a high vapor pressure liquid, having a vapor pressure of 5 kPa or greater and a freezing point of about 50 C. or less, in thin layers onto the surface;
simultaneously with cryogenic cleaning of the surface.