Optical mount with UV adhesive and protective layer

Details Optical mount with UV adhesive and protective layer Optical mount with UV adhesive and protective layer

2000-05-09

2001-09-04

Schuberg, Darren (Department: 2872)

Optical: systems and elements

Having significant infrared or ultraviolet property

C359S361000, C359S819000, C359S359000

Reexamination Certificate

active

06285496

ABSTRACT:

BACKGROUND OF INVENTION
1. Field of the Invention
The invention relates to an assembly including a holder—in particular, a mount—and a transparent, preferably optical, component that transmits in the ultraviolet spectral region, and more particularly to an assembly in which an adhesive can be hardened by means of UV light within a given spectral distribution.
2. Discussion of Relevant Art
Japanese Patent document 8-72300 provides an example of such an assembly with an ultraviolet curable adhesive. Such assemblies form, among other things, mounted lenses and the like of illumination systems and projection systems for microlithography.
Adhesive bonding to a mount is known, for example, for automobile and architectural glass, wherein the adhesive is protected from the effects of solar IN irradiation by means of UV-absorbing fillers and protective layers.
Thin layers of dielectrics, and in protective layers with thicknesses in the micrometer range, are known in the optical field, and are applied by vacuum deposition, sputtering, PVD or CVD. Such a protective layer for UV hardening bonds is described in Japanese Patent publication 9-184917.
According to Naumann, Schroder, Constructional Elements of Optics, Munich and Vienna 1983, page 72, such layers of cryolite, magnesium fluoride, cerium fluoride, zinc sulfide and titanium dioxide have lower transmission limits of 0.12 to 0.4 &mgr;m. Tantalum pentoxide, hafinium dioxide and mixtures of them transmit from 0.3 &mgr;m or 0.32 &mgr;m, according to Soviet Patent Document SU 48 23 642/33.
In general, the exact reflection, absorption, and transmission spectra of these thin layers in the Deep Ultianolet (DUV) region are not known, since the effects of the substrate and of the spectrometer/monochromator components are difficult to detect, and these materials have not been tested outside the planned field of application.
It has been found that the known mount adhesives based on epoxy resin, which can be hardened with UV light of the Hg-I line, can be considerably damaged by irradiation with DUV light at 248 nm and even more at 193 nm, in DV projection exposure equipment, and by their failure limit the life of the equipment.
DUV absorbing fillers in the adhesive mass do not prevent failure of the boundary layer of the adhesive adjacent to the quartz glass.
SUMMARY OF INVENTION
The object of the invention is to provide an assembly of the stated kind, in which the adhesive can be hardened with UV light, particularly the Hg-I line, and is also stable against UV light in useful spectral regions, especially in the short wavelength DUV region. The reflection of light from the region of the adhesive is to be suppressed as far as possible, since such scattered light has a troublesome effect in the optics. A process for producing the assembly and use of the assembly also are objectives of the invention.
This object is achieved by an assembly having a holder, a transparent component that transmits in the ultraviolet (UV) spectral region and is adhered by means of an adhesive that is hardenable by UV light in a given spectral region, and a layer that is applied by thin film technology on the transparent component in a region of the adhesive and transmits UV light of the given spectral region suitable for hardening the adhesive and to a high degree obstructs transmission of UV light within a useful spectral region by absorbing and/or reflecting light within the UV spectral region transmitted by the transparent component.
The production process according to the invention involves producing a transparent optical component attached to a mount by means of UV-hardenable adhesive by selecting a thin film layer to transmit light suitable for hardening the adhesive and to a high degree obstruct transmission of UV light in a useful spectral region by absorption and/or reflection, within the spectral regions transmitted by the optical component, and covering the component with a thin layer in the region of the adhesive by means of tin film technology. The assembly can be used in microlithogrophy projection exposure equipment
Thus, staring from the established mounting technique with UV hardening adhesives, by the introduction of a single coating, that can be integrated with the treatment for application of anti-reflection layers, which is required in abase, it is possible to permanently mount the lens that is suitable for DUV.


REFERENCES:
patent: 5493442 (1996-02-01), Buchholz et al.
patent: 62184079 (1987-08-01), None
patent: 09184917 (1987-08-01), None

Affiliated with

Also associated with

Rating

Optical mount with UV adhesive and protective layer does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Optical mount with UV adhesive and protective layer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical mount with UV adhesive and protective layer will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2443618