Sensor Electronic Technology, Inc. (SET) has been awarded two Small Business Innovation Research (SBIR) Phase II contracts to develop technology for high-power microwave transistors and deep ultraviolet light emitters using novel single crystal bulk AlN substrates.
The Missile Defense Agency is funding work on transistors, while DARPA is supporting the development of ultraviolet emitters.
These two-year programs are focused on improved performance of the devices fabricated on very-low defect density AlN substrates.
“This is a huge boost to our efforts in developing this new and exciting technology,” says Remis Gaska, president and CEO of SET. “We hope to advance the quality of epitaxial materials for fabrication of III-Nitride based electronic and optoelectronic devices to a whole new level.”
SET is purchasing novel single crystal bulk AlN substrates from Crystal IS, Inc. based in Latham, NY. The two companies started their collaborative effort on evaluating AlN substrates for growth of epitaxial wafers almost two years ago and jointly demonstrated stimulated emission at 260 nm.
A substantial reduction in defect density compared to devices grown on more conventional SiC substrates is expected to improve reliability and breakdown characteristics, increase microwave power, and reduce device noise.
The thermal conductance of AlN substrates is significantly higher than that of sapphire or silicon substrates, and this provides an important advantage for high-power applications.
High-power transistors are key building blocks for microwave power amplifiers (MPAs). MPAs are components in transmit/receive modules of both military and commercial radars and communications systems, including networks of base stations for wireless communications.
Ultraviolet light emitters
Higher-quality epitaxial layers grown on bulk AlN substrates are expected to dramatically improve the output power of ultraviolet LEDs and enable the development of laser diodes, particularly in deep-UV spectral range (wavelength <300 align="nm)." align="p">Currently, the main sources of deep-UV light are mercury lamps. Compared with such sources, III-nitride deep-UV LEDs and lasers are environmentally friendly, operate at lower voltages, and have lifetimes that are an order of magnitude longer.
Such UV emitters will find numerous applications for bio-agent detection, spectroscopy, water and air purification, on-spot disinfection and food safety inspections, UV curing, medicine, and solid-state lighting.