Nearly Ideal Current–Voltage Characteristics of Schottky Barrier Diodes Formed on Hydride-Vapor-Phase-Epitaxy-Grown GaN Free-Standing Substrates

Abstract

The current–voltage characteristics of Schottky barrier diodes formed on GaN(0001) free-standing substrates with net donor concentrations of 7.6×1015–1.4×1017 cm-3 are discussed. The substrates were grown by hydride vapor phase epitaxy. Ni Schottky contacts were directly formed on chemical–mechanical-polished Ga-polar faces of the substrates. Nearly ideal characteristics for both directions were obtained. The ideality factors for forward characteristics are 1.02–1.05, very close to unity. The reverse characteristics agree well with calculations based on thermionic-field emission theory without any fitting parameter.

GaN for automotive applications

“…However, the performance of GaN vertical devices is inferior to SiC and Si power devices as yet though the material potential of GaN is very high. Recent diode researches have revealed that the quality of recent GaN substrates is enough to apply to high voltage devices [18][19][20]. We have confirmed that edge and mix (edge + screw) dislocations included in the GaN substrate do not induce leakage current though the dislocation density was ~ 10 6 cm -2 [21].…”

Highly-stable and low-state-density Al2O3/GaN interfaces using epitaxial n-GaN layers grown on free-standing GaN substrates

“…3 In addition, the Schottky diodes on the GaN layers with low dislocation densities showed nearly ideal I-V characteristics according to a simple thermionic field emission model. 4 These results indicate highly improved crystalline quality of the current n-GaN epitaxial layers grown on the GaN substrates.…”

Surface acoustic waves in semi-insulating Fe-doped GaN films grown by hydride vapor phase epitaxy

“…23 Then the values of the depletion region width below the Ni/ Au electrodes were about 4.4 lm and 0.3 lm for sample 1 and sample 0, respectively. In addition, due to the existence of surface states, there is surface band bending and surface depletion region in GaN which is not covered by metal electrodes.…”