Demonstration of GaN Impact Ionization Avalanche Transit-Time (IMPATT) Diode

Wide bandgap semiconductors, such as gallium nitride (GaN) and silicon carbide (SiC), have bandgap energies larger than 3 eV with high breakdown electric fields, showing the advantage on powerful IMPATT diodes. SiC IMPATT diodes have been successfully demonstrated and shown excellent performances in X-band applications [1] , [2] . Although a few theoretical studies have shown the great potential of GaN for powerful IMPATT diodes [3] , [4] , no experimental study has been reported so far. Taking advantage of the single crystalline GaN substrates enabling high quality GaN films, avalanche capability has been demonstrated [5] – [9] . In this study, we demonstrated a GaN-based IMPATT diode experimentally by using a n-i-p epitaxial structure grown on a bulk GaN substrate.