Patent ID: 8810775

Claim:
An extreme ultraviolet (EUV) mirror module for use with EUV radiation, comprising: a substrate made of either nickel, nickel alloy, silicon or silicon-carbide and having a body with a curved upper surface that has surface irregularities, a first curvature and a first surface accuracy, the substrate having at least one cooling channel having cooling channel portions; a nickel electroformed mirror having front and rear curved surfaces and having a thickness of between 1 mm and 2 mm, the front and rear curved surfaces having a second curvature with a second surface accuracy that is greater than the first surface accuracy, wherein the second surface accuracy is at least 1 micron root-mean square (RMS), and wherein the first curvature approximately matches the second curvature; and a self-adjusting metallic conductive bonding material disposed in a region between the substrate curved upper surface and the electroformed mirror curved rear surface, the bonding material being flowable at a melting temperature to have a thickness between 10 microns and 1000 microns that conformally fills the region and fills the substrate surface irregularities, and bonds the substrate to the electroformed mirror at a temperature below the melting temperature while establishing thermal contact between the substrate and the electroformed mirror.