Sputter deposition-induced electron traps in epitaxially grown n-GaN

We have used deep level transient spectroscopy to study the electrical properties of defects introduced in epitaxial n-GaN during sputter deposition of Au Schottky contacts. Four defects, located 0.22±0.02, 0.30±0.01, 0.40±0.01, and 0.45±0.10 eV below the conduction band, were characterized. The first of these defects has similar electronic properties as a radiation induced defect in GaN, while the second appears to be the same as a defect in the as-grown material. The latter two defects have not previously been observed in as-grown or processed epitaxial GaN.