06 Oct 2006
SemiLEDs, a company developing novel light emitters based on a copper alloy substrate, has ordered a high-volume production machine from Aixtron.
US-based SemiLEDs has ordered a high-volume MOCVD reactor to scale up the manufacture of its vertical-design GaN LEDs.
The 24x 2 inch Aixtron machine will be installed in the company's facility at the Hsinchu Science Park in Taiwan, alongside its existing range of MOCVD equipment.
SemiLEDs has pioneered a unique chip design that is based on the use of copper-alloy substrates. The novel substrate material aids heat dissipation and means that the chips can be driven at a very high current to increase light output without degrading efficacy.
In a recent article for Compound Semiconductor magazine, SemiLEDs CEO Trung Doan showed how copper-alloy LEDs with a large chip size (1 mm) were just as efficient as much smaller chips.
LEDs based on the conventional sapphire substrate show a much reduced efficiency when their size is increased and their light output saturates at drive currents above about 1 A (see related magazine article for details).
SemiLEDS initially grows its devices on sapphire substrates, before transferring the epitaxial layers onto the metal alloy. The devices can withstand a drive current of more than 3 A without any noticeable light output power saturation, Doan claims.