Effect of hydrostatic pressure on the barrier height of Ni Schottky contacts on n-AlGaN

摘要

We report measurements of the Schottky barrier height of Ni contacts on Ga-polarity n-Al_(0.08)Ga_(0.92)N as a function of pressure. With applied hydrostatic pressure, Al_(0.08)Ga_(0.92)N Schottky diodes show a decrease in the forward bias current, and correspondingly an increase in the barrier height, which is approximately twice as large as that previously reported for Schottky contacts on Ga-polarity n-GaN. The observed change in barrier height with pressure is attributed to a combination of band structure and piezoelectric effects. The larger change of barrier height for Al_(0.08)Ga_(0.92)N can be explained by its larger piezoelectric constants and smaller density of interface states at the metal-semiconductor interface compared to GaN.