AlN thin films deposited by DC reactive magnetron sputtering: effect of oxygen on film growth

GARCÍA MOLLEJA J.; GÓMEZ B.; FERRÓN J.; GAUTRON E.; BÜRGI J.M.; ABDALLAH B.; DJOUADI M.A.; FEUGEAS J.; JOUAN P.-Y.

European Physical Journal Applied Physics

EDP Sciences

Año: 2013 vol. 64 p. 20302 - 20302

1286-0050

Aluminum nitride is a ceramic compound with many technological applications in many fields, for example optics, electronics and resonators. Contaminants play a crucial role in the AlN performance. This paper focuses mainly in the effect of oxygen when AlN, with O impurities in its structure, is grown on oxidized layers. In this study, AlN thin films have been deposited at room temperature and low residual vacuum on SiO2/Si (100) substrates. AlN films were grown by DC reactive magnetron sputtering (aluminum target) and atmosphere composed by an argon/nitrogen mixture. Working pressure was 3 mTorr. Film characterization was performed by AES, XRD, SEM, EDS, FTIR, HRTEM, SAED and band-bending method. Our results show that oxidized interlayer imposes compressive stresses to AlN layer, developing a polycrystalline deposition. Indeed, when film thickness is over 900 nm, influence of oxidized interlayer diminishes and crystallographic orientation changes to the (0002) one, i.e., columnar structure, and stress relief is induced (there is a transition from compressive to tensile stress). Also, we propose a growth scenario to explain this behaviour.