Picogiga develops GaN epiwafers on silicon
Optimized GaN power microwave devices on silicon are the premier emerging solution to the demand for more efficient components, according to Jean-Luc Ledys, Picogiga s chief operating officer. “Picogiga is pursuing its strategy to supply high-performance epitaxial layers required for new generations of RF devices,” he said. “This is a progressive step in our III-Vs material roadmap for high-power, high-speed applications.”
Most AlGaN/GaN HEMTs are offered on sapphire or silicon carbide substrates, and these approaches are hampered by poor thermal conductivity, high procurement costs, and lack of availability for large-diameter wafers.
“Combining the performance benefits of GaN with the cost advantages of large-area silicon will help ensure broad commercial availability of GaN-based wafers,” said Ledys.
While silicon is desirable as a substrate material due to its many advantages (low cost, high quality and ready supply), it has shown to be the most difficult substrate on which to grow compound semiconductor layers, particularly GaN.
Picogiga says that its MBE deposition process overcomes the challenge of growing GaN on silicon, enabling both the material properties of GaN and the advantages of silicon substrates to be leveraged.
Picogiga s process also confirms the viability of silicon as a manufacturable platform for AlGaN-based devices from the standpoint of epitaxy, device performance and thermal power handling. HEMT devices based on this structure exceed 6 W/mm at 2 GHz, can handle operating frequencies ranging from 5 to 10 GHz with a transconductance (Gm) of 350 mS/mm, and can sustain voltage up to 60-70 V. Such performance results make Picogiga s AlGaN/GaN product family suitable for 3G base-station RF power amplifiers, as well as K-band radar applications.