Effect of Surface Treatment in Au/Ni Schottky Diodes Formed on Cleaved m-Plane Surfaces of Free-Standing n-GaN Sub-strates

摘要

We fabricated and characterized Au/Ni Schottky contacts on cleaved m-plane free-standing n-GaN surfaces (i) without any surface treatment, (ii) with H_2O_2 treatment, or (iii) with HCl treatment. The as-cleaved samples showed I-V characteristics with small n-values and less diode-to-diode variation. However, the H_2O_2 samples had much smaller Schottky barrier height. Whereas the HCl samples exhibited significantly large diode-to-diode variation. It is confirmed that cleaving without any surface treatment can provide a cleaner surface to form Schottky diodes on m-plane n-GaN surfaces than that with conventional HCl treatment.