From epitaxy to backside process: Reproducible AlGaN/GaN HEMT technology for reliable and rugged power devices

We report on a reproducible 3'' GaN HEMT technology showing good device performance and reliability. AlGaN/GaN HEMT structures are grown on semi-insulating SiC substrates by MOCVD with sheet resistance uniformities better than 3%. Device fabrication is performed using standard processing techniques involving both e-beam and stepper lithography. The process technology exhibits an excellent uniformity across a single wafer and a high reproducibility between individual wafers of the same or a different batch. Good performance is shown at different examples, such as large power bars for 2 GHz frequency as well as MMICs running at 18 GHz. Reliability tests are performed at both radio frequency (RF) and direct current (DC) stress conditions and indicate promising device stability