Engineers at Cornell University, New York, say they have developed a process that could reduce the cost of producing superconducting films for integrated circuits. The process, known as high-pressure reactive evaporation, uses ceramic materials discovered last year that start superconducting at the relatively high temperature of -183`C. It lowers fabrication temperatures from about 850`C to 700`C. This in turn reduces the risk of damage to other components on the chips. The cost of raw materials may also be cut using a Zirconium Oxide base, estimated at one-tenth the price of Strontium Titanate which is commonly used as a substrate. The process could lead to the use of inexpensive liquid Nitrogen for cooling and could open up a large number of practical applications. Superconductors offer no electrical resistance to current flow and could replace the present metal connections among components on chips. These produce unwanted resistance which slows down transmission rates and generates damaging heat. Cornell says the Yttrium Barium Copper Oxide film made using its process could sustain a current of about 1mA per square centimetre.
