XPS studies on AlN thin films grown by ion beam sputtering in reactive assistance of N+/N2+ ions: Substrate temperature induced compositional variations

TL;DR

This study uses XPS to analyze how substrate temperature affects the composition of AlN thin films grown by ion beam sputtering with reactive nitrogen ions, showing increased AlN formation at higher temperatures.

Contribution

It demonstrates that substrate temperature alone can significantly enhance AlN content in thin films during ion beam sputtering deposition.

Findings

AlN content reaches up to 74 at.% at higher substrate temperatures

Formation of other phases is identified based on elemental analysis

Higher substrate temperatures improve AlN surface composition

Abstract

We report on an XPS study of AlN thin films grown on Si(100) substrates by ion beam sputter deposition (IBSD) in reactive assistance of N+/N2+ ions to unravel the compositional variation of their surface when deposited at different substrate temperatures. The temperature of the substrate was varied as room temperature (RT), 100oC and 500oC. The binding energy of Al-2p, N-1s and O-1s core electrons indicate the formation of 2H polytypoid of AlN. The increase in concentration of AlN with substrate temperature during deposition is elucidated through detailed analysis with calculated elemental atomic concentrations (at. %) of all possible phases at the film surface. Our results show that predominate formation of AlN as high as 74 at. % is achievable using substrate temperature as the only process parameter. This high fraction of AlN in thin film surface composition is remarkable when compared to other growth techniques. Also, the formation of other phases is established based on their elemental concentrations.