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

• Published in: European physical journal. Applied physics Vol. 64; no. 2; p. 20302
• Main Authors: García Molleja, Javier, Gómez, Bernardo José, Ferrón, Julio, Gautron, Eric, Bürgi, Juan, Abdallah, Bassam, Djouadi, Mohamed Abdou, Feugeas, Jorge, Jouan, Pierre-Yves
• Format: Journal Article
• Language: English
• Published: Les Ulis EDP Sciences 01.11.2013
• ISSN: 1286-0042; 1286-0050
• DOI: 10.1051/epjap/2013130445

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 (1 0 0) 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 (0 0 0 2) 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.