8 August 2011

Translucent launches vGaN wafer templates for epi growth of GaN devices

Translucent Inc of Palo Alto, CA, USA (a subsidiary of Australian-listed company Silex Systems Ltd), which provides rare-earth-oxide (REO) engineered silicon substrates for low-cost epitaxy, has announced the commercial availability of its vGaN family of silicon-based wafer templates. The firm says that vGaN (‘virtual gallium nitride’) products provide a low-cost, high-quality epitaxial surface for the growth of GaN devices such as light-emitting diodes (LEDs) or field-effect transistors (FETs).

The vGaN product line is claimed to be the world’s first commercial REO-based family of III-N semiconductors with scalable GaN-on-Si wafers. The use of crystalline REO layers provides stress relief and wafer flatness through customized lattice engineering, leading to a high-quality growth surface, says Translucent. In addition, the wide bandgap of the REO layer is expected to lead to much higher breakdown-voltage characteristics for FETs grown on vGaN.

The firm says that vGaN provides a semiconductor growth surface that has the physical properties of GaN, but uses a silicon substrate upon which is grown an epilayer of REO material that accommodates a top epilayer of Group III nitrides such as GaN. The vGaN substrate enables, for the first time it is claimed, industry-standard metal-organic chemical vapor deposition (MOCVD) growth processes with the low-cost structures and economies of scale currently enjoyed by the silicon industry.

“We are bringing a decade of Translucent REO epitaxial experience to bear on the challenge of enabling GaN growth to scale cost-effectively well beyond current limitations,” notes general manager Michael Lebby. “Our vGaN platform is an ‘on-silicon’ technology, allowing us to harness mature silicon-substrate technologies and their low costs, and we expect this to have an extremely beneficial impact in driving down costs for GaN-based LEDs and FETs,” he adds. 

GaN is typically grown on sapphire substrates, which are significantly more expensive at large diameters, especially 200mm and larger. Additionally, a major challenge facing device manufacturers is the handling of large, heavy and expensive sapphire wafers. Such handling may require the purchase of special handling equipment for the fabrication plants. Conversely, the widely used infrastructure of fabrication plants that are ready to run silicon wafers up to 200mm already exists, making large-diameter silicon a suitable choice to bring economies of scale into the lighting (LED) and power electronics (FET) industries, says Translucent.

The vGaN wafers are already available at 100mm diameters, with 150 and 200mm to be available during the next year.

See related items:

Translucent launches GaN-on-Si templates with embedded DBR mirrors

Tags: GaN-on-Si templates LEDs MBE

Visit: www.translucentinc.com