720 V quasi-vertical GaN-on-silicon p–n diodes with surge capability fabricated using selective area growth

This work demonstrates, for the first time, avalanche breakdown capability in quasi-vertical gallium nitride (GaN) on silicon (Si) substrates employing localized epitaxial growth. On industry-standard 200 mm wafers, we integrated an 8 μm thick GaN drift layer onto Si, enabling the fabrication of 720 V quasi-vertical p–n diodes. This method yields high-performance power devices in CMOS-compatible cleanrooms at a reduced cost. The GaN p–n junctions exhibit a specific on-resistance of 3.3 mΩ cm2, a current on/off ratio exceeding 1010, and a current density of 1.4 kA/cm2 at 10 V. Robust avalanche behavior was confirmed through temperature-dependent reverse bias measurements from 298 to 373 K, and over 3000 over-voltage surge ruggedness was demonstrated by unclamped inductive switching stress tests. These results underscore the advantages of localized epitaxy for achieving high-quality GaN layers on Si, paving the way for scalable integration of high-voltage GaN power devices with conventional Si technology.