Bipolar pulsed reactive magnetron sputtering of epitaxial AlN- films on Si(111) utilizing a technology suitable for 8″ substrates

Abstract

This paper discusses the development of a reactive sputtering process for the deposition of epitaxially grown AlN films on Si(111) using a technology suitable for 8″ substrates. X-ray diffraction (XRD) and rocking curves (RC) are used to determine the crystalline orientation. The influence of substrate temperature, target-substrate distance and target voltage on the full width at half maximum (FWHM) of the RC is investigated. The film deposition was performed on Si(111) wafers and on AlN-on-Si(111) templates prepared by metal organic chemical vapor deposition (MOCVD). Based on the sixfold symmetry identifiable in the pole figure of the AlN(302) plane reflections, oriented in-plane film growth on Si(111) was verified for the process. Best oriented films sputtered directly on Si(111) achieved for 500 nm AlN films featured a RC-FWHM of 0.93° of AlN(100) and 0.77° of AlN(002). Root mean square roughness (RMS) of the samples varied between 2.3 nm and 2.8 nm. The deposition rate was between 70 nm/min and 100 nm/min. Films deposited onto the MOCVD templates grew maintaining the crystalline quality of the MOCVD substrate, verified by the FWHM of the RC of in-plane and out-of-plane reflections. • Sputter epitaxy of AlN on Si(111) using a a technology suitable for 8″ substrates • Process at low temperature (850 °C) featuring high deposition rates (1.3 nm/s) • Investigating influences of temperature, target-substrate distance, target voltage • Improvement of crystalline orientation achieved • Indication of local optimum of crystalline quality regarding target voltage