Schottky barrier contacts formed on polar and nonpolar Mg_xZn_(1-x)O films grown by remote plasma enhanced MOCVD

摘要

The growth of Mg_xZn_(1-x)O films of both polar and nonpolar orientation in was successfully carried out by remote-plasmaenhanced MOCVD (RPE-MOCVD) technique. The polar face of as-grown film had a vertically aligned columnar growth with respect to the sapphire (11–20) substrate. These columns had an average diameter of about 40 nm. In contrast, the nonpolar face of as-grown film had a sword-shape lying with an average width of 250 nm on the sapphire (10–12) substrate. Au/Schottky diodes (SDs) were fabricated on both polar face of c-plane (0001) Mg_xZn_(1-x)O and nonpolar face of a-plane (11–20) Mg_xZn_(1-x)O. A rectifying behavior had been achieved and a series resistance was increased with Mg contents in both polar and nonpolar diodes. A residual electron concentration was decreased with the Mg content from 3×10~(17) cm~(-3) at x=0 to 1.2×1016 cm~(-3) at x=0.18 in the case of nonpolar films.