Superconformal electrodeposition using derivitized substrates. (General Developments).State-of-the-art manufacturing of microelectronics involves the electroplating electroplating: see plating. electroplating Process of coating with metal by means of an electric current. Plating metal may be transferred to conductive surfaces (e.g., metals) or to nonconductive surfaces (e.g. of copper for on-chip wiring. Electroplating in the presence of organic additives enables seam-free and void-free filling of trenches and vias to create the horizontal and vertical "wires" of the integrated circuit integrated circuit (IC), electronic circuit built on a semiconductor substrate, usually one of single-crystal silicon. The circuit, often called a chip, is packaged in a hermetically sealed case or a nonhermetic plastic capsule, with leads extending from it for . Recently, a simple two-step process has been developed by NIST (National Institute of Standards & Technology, Washington, DC, www.nist.gov) The standards-defining agency of the U.S. government, formerly the National Bureau of Standards. It is one of three agencies that fall under the Technology Administration (www.technology. researchers, which should allow deeper features to be filled with greater control over the process. These deeper features are critical for integrated circuits Integrated circuits Miniature electronic circuits produced within and upon a single semiconductor crystal, usually silicon. Integrated circuits range in complexity from simple logic circuits and amplifiers, about 1/20 in. (1. in the next five years. The substrate is first "derivitized" with a sub-mono-layer coverage of catalyst and then transferred for electroplating in a cupric sulfate electrolyte containing an inhibitor. When catalyst coverage is optimal, superconformal or "bottom-up" filling of trenches and vias is observed. If the catalyst coverage is too low or high, conformal con·for·mal adj. 1. Mathematics Designating or specifying a mapping of a surface or region upon another surface so that all angles between intersecting curves remain unchanged. 2. or subconformal deposition occurs, resulting in void formation within the wires. The filling behavior of the derivitized features is quite similar to that obtained using a single (conventional) electrolyte containing both catalytic and inhibiting species. Success of the two-bath approach provides strong support for the curvature enhanced accelerator coverage" mechanism (CEAC CEAC Chemical Engineering and Applied Chemistry CEAC Conférence Européenne de l'Aviation Civile (French: European Civil Aviation Conference) CEAC Compensatory Education Advisory Committee ) of Superconformal film growth developed at NIST. From a technical perspective, the two-step process offers an interesting solution to the difficult control issues associated with catalyst destruction and related aging effects known to occur in the "conventional" single-electrolyte superfilling process. CONTACT: Thomas Moffat, (301) 975-2143; thomas.moffat@nist.gov. |
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