Low-Cost Manufacturing Methods for Ultra-Flat Electronic Substrates and Prceision Optics

A low-cost, manufacturing technology is proposed to polish, defect-free, crystallographically perfect surfaces on all economically important semiconductor and optical materials. The technology is applicable to the high-volume production of a broad range of military and commercial components requiring surface accuracies between 0.3 and 0.006 microns. The feasibility to combine precision optical polishing techniques with fast, defect-free, chemical-mechanical polishing methods will be demonstrated. An innovative, wear-resistant and stable, fluorocarbon lap is used to replicate its precision surface onto the workpiece using a silica hydrosol slurry. To address the immediate requirements of the microelectronics industry, HTG will first demonstrate the ability to polish silicon wafers, silicon-on-insulator (SOI) substrates, and to planarize interlevel dielectrics to a precision not possible using resilient polymeric laps. The methods are equally applicable to superpolishing precision glass and metal optical components. In addition to enhancing lithographic resolution, process latitude, and yield for IC's with 0.35 - 0.25 micron features on bulk silicon, HTG's methods can used to fabricate larger, lower-cost, SOI substrates for commercial CMOS-SOI logic and SRAM chips. Anticipated Benefits: Production of DRAM's, SRAM's, Flash EPROMS, and HDTV related memory chips; high-speed SMOS/SOI chips. Superpolished optics for projection x-ray lithography, synchrontron, and high-energy lasers.