Investigation of hydrogen impurities in PE-ALD AlN thin films by IBA methods.

Hydrogen impregnation is one of the main sources of contamination in AlN thin films obtained by atomic layer deposition method (ALD) as many studies report. Such impurities can be potentially detrimental to mechanical and electrical properties of the material. In this study methods belonging to ion-beam analysis (IBA) group, namely: elastic recoil detection analysis (ERDA), nuclear reaction analysis (NRA) and secondary-ion mass spectrometry (SIMS) were utilized to examine AlN thin films obtained by plasma-enhanced atomic layer deposition (PE-ALD) with use of trimethylaluminium (TMA) and N 2 +H 2 gas mixture as precursors. Several depositions of AlN layers were carried out with different values of N 2 +H 2 flux intensity (20, 100, 150 sccm) and TMA pulse (0.06, 0.12, 0.15 s) in order to investigate whether such alterations would produce any effect on the resulting films. Data obtained within the scope of this study suggest that AlN grown by PE-ALD exhibit rather low amounts of hydrogen impurities, especially when compared to thermal ALD. Furthermore, the effect of high-temperature treatment in N 2 atmosphere was studied and was found out to produce a positive effect on the chemical composition of AlN films. • AlN thin films were deposited by PE-ALD using trimethylaluminium (TMA) and N 2 +H 2 gas mixture. • The films were analyzed by IBA methods: SIMS, NRA and ERDA. • The hydrogen was quantified for all samples. • The IBA methods also revealed oxidization of the films, which is alleviated by high-temperature annealing in N 2 atmosphere. [ABSTRACT FROM AUTHOR]