Researchers based in the Republic of Ireland, Northern Ireland and the USA have developed a wafer-scale method to integrate III-V devices with silicon and other substrates [John Justice et al, Nature Photonics, published online 19 August 2012].

The researchers were based at Ireland’s Tyndall National Institute, University College Cork, Ireland, Semprius Inc of North Carolina, and Seagate Technology, Northern Ireland.

The team foresees applications arising within the hard-drive and more general electronics industries. For hard-drives, the new heat-assisted magnetic recording (HAMR) technology uses a laser light sources to increase storage densities. Seagate reported the achievement of 1terabit/inch2 density in March this year. This application requires III-V laser diodes integrated with alumina/titanium carbide (AlTiC) substrates. Another potential application is increased signal data rates for CMOS-based circuits on silicon.

The transfer printing was performed using a microfabricated stamp consisting of elastomer and glass layers.

The researchers comment: “These and other forthcoming applications will require laser device volumes that are multiples of those in use today. A prerequisite for any design is that the laser can be efficiently integrated with the low-cost manufacturing infrastructure and planar processes already established for AlTiC and silicon substrates.”

The new wafer-scale method involved transferring epitaxial material ‘coupons’ from a III-V wafer to the new substrate in batches. The transferred material is then processed into III-V laser diodes.

To read more: http://www.semiconductor-today.com/news_items/2012/SEP/TYNDALL_040912.html