Abstract: A photomask assembly is described having a frame for supporting a transparent pellicle above a photomask substrate, defining a closed pellicle space overlaying the substrate. The frame is formed of a porous material configured to allow the pellicle space to be purged with an inert gas within a reasonable processing time period, thereby removing any harmful chemicals that might be present. The frame preferably is made by a method that includes preparing a gel by a sol-gel process, drying the gel, and partially densifying the dry gel. The resulting frame has a gas permeability to oxygen or nitrogen higher than about 10 ml.mm/cm2.min.MPa, an average pore size between 0.001 micrometer and 10 micrometers, and a coefficient of thermal expansion between 0.01 ppm/° C. and 10 ppm/° C.

Abstract: An encapsulant is described for an optoelectronic device or optical component, which provides a coefficient of thermal expansion of less than 50 ppm/° C., with a variation of less than ±30%, and further provides an optical transmittance of at least 20% at a wavelength in the range of 400 to 900 nm, at an encapsulant thickness of about 1 mm. The encapsulant includes a filler consisting essentially of glass particles having diameters smaller than 500 ?m, being essentially free of titania and lead oxide, and having a refractive index in the range of 1.48 to 1.60, with a variance of less than about 0.001.

Abstract: An encapsulant is described for an optoelectronic device or optical component, which provides a coefficient of thermal expansion of less than 50 ppm/° C., with a variation of less than ±30%, and further provides an optical transmittance of at least 20% at a wavelength in the range of 400 to 900 nm, at an encapsulant thickness of about 1 mm. The encapsulant includes a filler consisting essentially of glass particles having diameters smaller than 500 ?m, being essentially free of titania and lead oxide, and having a refractive index in the range of 1.48 to 1.60, with a variance of less than about 0.001.

Abstract: An encapsulant for use with opto-electronic devices and optical components incorporates a filler made from a glass that has been processed into particle form and heated to a predetermined temperature for a predetermined time, along with an epoxy having an index of refraction matched to that of the glass and heated to a predetermined temperature for a predetermined time, to prevent settling of the filler particles after mixing the filler particles with the epoxy, and thereby obtaining uniform dispersion of the particles within the epoxy. The encapsulant provides for high light transmittance, and its coefficient of thermal expansion can be varied by varying the amount of filler without substantially altering the optical properties of the encapsulant. The coefficient of thermal expansion variation within the encapsulant preferably is less than 30%, due to uniform dispersion of the filler particles within the epoxy.