Optical technological applications have upgraded polishing, including flat-surface polishing, to an extremely high level of geometrical precision. We deal with the application of this type of precision technology for the preparation of, e.g., silicon or fused-silica wafers that are thin compared to their diameter. To this end a standard optical polishing process using a double-sided polishing machine was modified by giving the polishing pad holder an adaptable curvature. By carefully choosing the process conditions 10-cm-diameter silicon and fused-silica wafers (500-µm thickness) were obtained with a very small deviation from parallelism in the 0.01-µm range. The level of smoothness, surface and subsurface damage, was identical with that required for integrated-circuit processing.
© 1994 Optical Society of America
Jan Haisma, Frank J. H. M. van der Kruis, Bert A. C. M. Spierings, Jan Jaap Baalbergen, Bart H. Bijsterveld, Ruud Brehm, Jan H. P. M. Faasen, Jan. J. C. Groenen, Peter W. de Haas, Theo B. J. Haddeman, Theo M. Michielsen, and Jaap Vijfvinkel, "Improved geometry of double-sided polished parallel wafers prepared for direct wafer bonding," Appl. Opt. 33, 7945-7954 (1994)