ESTnet Premier Member IQE has been acknowledged for supplying commercially ready 100mm gallium nitride (GaN) on silicon carbide (SiC) epiwafers that were used to produce record results for both high gain and high power density transistor devices, enabling for the first time, flexible monolithic microwave integrated circuit (MMIC) design for efficient high-voltage/high-power broadband operation at frequencies ranging from 0 – 40 GHz.
High frequency microwave capabilities of up to 40GHz (also known as Ka-band) are essential for satellite communications and will become increasingly important for next generation (5G) wireless communications. However, until now, designers have faced compromises between frequency and power.
The breakthrough results are published in IEEE Electron Device Letters, Vol 36, No. 10, October 2015 in an article by Fitch et al. entitled: Implementation of High-Power-Density X-Band AlGaN/GaN High Electron Mobility Transistors in a Millimeter-Wave Monolithic Microwave Integrated Circuit Process. The High Electron Mobility Transistor (HEMT) devices were produced using GaN on SiC wafers purchased from IQE by the US Air Force Research Laboratory, Sensors Directorate, Aerospace Components Division, Devices for Sensing Branch at Wright-Patterson Air Force Base in Dayton, OH.
The solution outlined in the published paper provides designers with the option of incorporating two different devices by implementing a 0.14-μm gate length GaN MMIC process capable of high-efficiency Ka-band operation while simultaneously achieving high power density X-band operation using the same process flow.
The authors demonstrated 7.7 W/mm at 35 GHz and VDS = 30 V on a standard 4 × 65-μm T-gated FET and then 12.5 W/mm at 10 GHz and VDS = 60 V on a 4 × 75-μm T-gated FET by adding a field plate. These are the highest reported power densities achieved simultaneously at X-band and Ka-band in a single wideband GaN MMIC process.
The epiwafers were produced at IQE’s New Jersey facility using Metal Organic Chemical Vapour Deposition (MOCVD) on 4′′ semi-insulating SiC substrates.
Dr. Wayne Johnson, VP of IQE’s Power Business Unit said:
“These results, achieved on our GaN on SiC epiwafers, demonstrate the ability of IQE to produce record-breaking, world leading results on commercial platforms that enable today’s leading edge satellite communications and will be essential for enabling next generation wireless technologies.”