IQE's GaN on Si achieves breakthrough results
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."
IQE is the leading global supplier of advanced semiconductor wafers with products that cover a diverse range of applications, supported by an innovative outsourced foundry services portfolio that allows the Group to provide a 'one stop shop' for the wafer needs of the world's leading semiconductor manufacturers.
IQE uses advanced crystal growth technology (epitaxy) to manufacture and supply bespoke semiconductor wafers 'epi-wafers' to the major chip manufacturing companies, who then use these wafers to make the chips which form the key components of virtually all high technology systems. IQE is unique in being able to supply wafers using all of the leading crystal growth technology platforms.
IQE's products are found in many leading-edge consumer, communication, computing and industrial applications, including a complete range of wafer products for the wireless industry, such as mobile handsets and wireless infrastructure, Wi-Fi, base stations, GPS, and satellite communications; optical communications, optical storage, laser optical mouse, laser printers & photocopiers, thermal imagers, leading-edge medical products, barcode, ultra high brightness LEDs, a variety of advanced silicon based systems and high efficiency concentrator photovoltaic (CPV) solar cells.
The manufacturers of these chips are increasingly seeking to outsource wafer production to specialist foundries such as IQE in order to reduce overall wafer costs and accelerate time to market.
IQE also provides bespoke R&D services to deliver customised materials for specific applications and offers specialist technical staff to manufacture to specification either at its own facilities or on the customer's own sites. The Group is also able to leverage its global purchasing volumes to reduce the cost of raw materials. In this way IQE's outsourced services, provide compelling benefits in terms of flexibility and predictability of cost, thereby significantly reducing operating risk.
IQE operates a number of manufacturing and R&D facilities facilities worldwide.