| 摘要 |
1279742 Semi-conductor devices; printed circuits. INTERNATIONAL BUSINESS MACHINES CORP 4 Jan 1971 [8 Jan 1970] 257/71 Headings H1K and H1R A film conductor comprises a metal containing an additive for retarding current induced mass transport of the metal. Reservoirs of the additive are disposed adjacent points where mass flux divergences, which cause depletion of the additive, occur. Such divergences occur, e.g. at interfaces with other materials in the current path and in thermal gradients. The depleted material is periodically replenished, e.g. six-monthly, from the reservoirs by heat treatment at 50-550‹ C. Typically, the conductors are of aluminium and contain copper as retardant. Iron, magnesium and silver are other retardants and the invention can also be applied to conductors of silver, gold and platinum. The conductors described constitute interconnections between integrated circuit devices formed in a silicon wafer by known planar techniques. A first layer of interconnections is first deposited over a silicon oxide, nitride or alumina passivating layer and form etched, a further layer of the insulant is then laid down, as by RF sputtering, and apertured at interconnecting points, and then a second layer of interconnections. Finally, a protective silica layer is deposited and apertured at terminal land locations where ball contacts are provided. The metal layers, e.g. of copper-doped aluminium, to which 3% by weight of silicon may be added to limit alloying to the silicon, are formed at a substrate temperature of 200‹ C. by evaporation from an alloy source, by co-evaporation from separate sources or by sequential evaporations of copper and aluminium followed by a heat treatment. Between these processes copper is deposited locally where required (see Figures, not shown) and overlain with chromium to improve the adhesion of subsequently deposited insulation. The invention may also be used with conductive films or substrates for interconnection to semi-conductor and other electronic devices. |
