Abstract: A method for constructing a photomask assembly using an encoded mark is disclosed. The method includes comparing a first encoded mark located on a photomask with a second encoded mark located on a pellicle. The first encoded mark includes one or more first symbols and the second encoded mark includes one or more second symbols. The method further includes mounting the pellicle on the photomask if at least one of the symbols of the first encoded mark matches at least one of the symbols of the second encoded mark.

Abstract: A method and apparatus for calibrating a metrology tool are disclosed. The method includes measuring a parameter of a contrast enhanced feature on an artifact using a metrology tool, where the contrast enhanced feature reduces random errors in the metrology tool during the measuring process. The measured parameter is compared with an initial parameter associated with the artifact and the metrology tool is adjusted until the measured parameter matches the initial parameter.

Abstract: An optical device structure for use where an optical fiber requires to be accurately aligned in an optically coupled relationship with another optical component in a package 100 comprises an optical fiber 16 mounted in a feedthrough tube 9 which is aligned with a laser 6 through an aperture 18 in a wall 4 of the package 100. The alignment is held by a first alignment means 10, in this case a sleeve spool, which is secured to the wall 4 and to the feedthrough tube 9 relatively close to the wall 4, and by a second alignment means 11, in this case a tubular bushing, which is also fixed to the wall 4 and to the feedthrough tube 9 in a region remote from the wall 4. The use of the two alignment means 10, 11 fixed in this manner permits the desired optical coupling to be accurately fine-tuned in fabrication by a novel technique.