Fast chip offers true integration

17 Jun 2002

Motorola has unveiled what it claims are the world's first 200 and 300 mm GaAs on Si wafers.

The breakthrough technology combines the best properties of workhorse silicon technology with the speed and optical capabilities of high-performance III-V compound semiconductors. It opens the door to full-scale integration of optical and electronic components.

The technology reduces the need for discrete components by combining light-emitting semiconductors with silicon integrated circuits on a single chip. It promises new applications, such as broadband fiber-optic cable to the home and collision avoidance systems in cars.

Motorola's research team, led by Jamal Ramdani, succeeded in growing very thin layers of gallium arsenide on a silicon substrate by introducing an intermediate layer of material between the two layers that can bond to both, reducing the strain between the two materials.

Previous attempts to make similar wafers resulted in dislocations or cracks as the two mismatched structures struggled to bond.

"One of our next goals is to complete the task of growing indium phosphide on silicon. This technology should support chip clock speeds of more than 70 GHz and long-wavelength lasers that are critical to fiber-optic communications," said Jim Prendergast, vice-president and director of Motorola's Physical Sciences Research Lab.

"More than 90% of the existing fiber-optic cable is still unused and under-utilized," added Semico Research Corporation's vice-president Bob Merritt. "This technology could be the switch that eventually turns on those communications channels."