Pulsed‐DC Sputtering of Highly C‐Axis AlN Film on Top of Si (111) Substrate

Abstract

This paper reports on pulsed DC sputtering of AlN film on top of Si (111) substrate. First, we tabulate major articles on reactive sputtering of AlN film on top of Si (111) substrate that were published in past 30 years. Then, we propose sputtering recipe to produce consistent and high crystal quality (as measured by FWHM of rocking curve) of AlN film across varying substrate temperature (250 to 450 ˚C) and sputtering powers (1200 to 2400 W). In addition, we demonstrate influence of both parameters to in‐plane stress, in agreement with similar trends that are reported in literature for AlN films on other substrates. The best sample is produced at substrate temperature of 350 ˚C and sputtering power of 1800 W, resulting in FWHM of rocking curve of 1.84o, surface roughness of 1 nm, and in‐plane stress of +300 MPa. The recipe from this work will be beneficial for integration of AlN thin film in CMOS and MEMS processes.