GaInN‐based tunnel junctions with high InN mole fractions grown by MOVPE

Abstract

We demonstrated low‐resistive GaInN‐based tunnel junctions with high In mole fractions (over 0.35) grown by metalorganic vapor phase epitaxy (MOVPE). A 2 nm heavily Mg‐doped Ga0.6In0.4N/15 nm heavily Si‐doped GaN tunnel junction was grown on a standard‐sized (310 × 310 µm2) LED. The tunnel junction showed 0.06 V drop at 20 mA (26 A/cm2), corresponding to 4 × 10−3 Ωcm2 as the resistivity. This result indicates that MOVPE‐grown tunnel junctions showed an almost comparable resistivity as conventional p‐contact. We also found that the tunnel junction resistivity is decreased to 4 × 10−4 Ω cm2 with an increase of current density up to 5 kA/cm2. A tunneling through midgap states was suggested from forward‐biased I–V characteristics of transmission line model test structures with the tunnel junctions.