Electrical characterization and morphological properties of AlN films prepared by dc reactive magnetron sputtering

Aluminum nitride (AlN) films were deposited by dc reactive magnetron sputtering on p-Si-(1 0 0) substrate in Ar–N2 gas mixtures. The effects of nitrogen concentration and sputtering power on AlN films deposition rate, crystallographic orientation, refractive index, and surface morphology are investigated by means of several characterization techniques. The results show that AlN films reasonably textured in (0 0 2) orientation with low surface roughness can be obtained with the deposition rate as high as 70 nm/min by the control of either target power or N2 concentration in the gas mixture. Increasing the dc discharge power, Al atoms are not completely nitridized and the Al phases appear, as well as the AlN phases. MIS (Metal–Insulator–Semiconductor) structures were fabricated and electrically evaluated by I–V (current–voltage) and C–V (capacitance–voltage) measurements at high frequency (1 MHz). The results obtained from C–V curves indicate that charges at the dielectric/semiconductor interface occur, and the dielectric constant values (extracted under strong accumulation region) are compatible with those found in literature.