ETCH ALIGNMENT OF CCD MOSAIC HYBRID

By relying on semiconductor lithography and processing techniques, we have fabricated a flat, precision aligned charge-coupled device (CCD) mosaic for astronomy. Modifications to the lithographic techniques use d in micromachining lead to a significant reduction in various residue deposits, allowing a smooth surface suitable for CCD alignment, Detai ls of the technique and the fabrication of a prototype mosaic are desc ribed, The composite device is flat to within +/-5 mu m, with rows/col umns oriented to within 20 ppm, The use of an existing technology with built in precision reduces many of the difficulties and expenses typi cally encountered with mosaic detector construction.