CHAMPAIGN, Ill. University of Illinois engineers have developed a novel direct-writing method for manufacturing metal interconnects that could shrink integrated circuits and expand microelectronics.
Integrated chips are made by wiring multiple transistors and electronic components together to perform complex functions. The connections between chips and circuit boards traditionally are made from pre-fabricated metal wires that connect to a designated bonding pad on a chip.
"Integrated functions require many wire connections. It's tedious and time-consuming to make and increases cost," said Min-Feng Yu, a professor of mechanical science and engineering at Illinois.
In addition, the bonding pad for traditional wire bonds takes up a substantial area of space. As technology has moved toward smaller electronics, shrinking wiring has been a substantial obstacle. Many microelectronic devices are much smaller than the required 50-by-50 micron square bonding site, prohibiting integrated functions on the very small scale.
"There's no existing cost-effective technology that would allow you to wire-bond microstructures," said Yu, "so let's get rid of those wires, and instead, why not directly produce them on-site between the connection points?"
Yu and graduate student Jie Hu developed a direct-write technique that produces tiny pure metal wires much smaller in diameter than traditional wires and requiring two orders of magnitude less bonding area. In a paper appearing in the July 16 edition of Science, they demonstrate as many as 20 of their new wires bonded to a single standard bonding site.
"This technique means the pads can be much smaller than what's needed for traditional wire-bonding technology," Yu said. This reduction in area could allow manufacturers to produce more chips per wafer of semiconductor material. It could also enable more complex integrated functions in microelectronics.
|Contact: Liz Ahlberg|
University of Illinois at Urbana-Champaign