Issue 33, 2024

Surface chemistry in atomic layer deposition of AlN thin films from Al(CH3)3 and NH3 studied by mass spectrometry

Abstract

Aluminum nitride (AlN) is a semiconductor with a very wide band gap and a potential dielectric material. Deposition of thin AlN films is routinely done by several techniques, including atomic layer deposition (ALD). In this study, we deposited AlN using ALD with trimethylaluminum (TMA) as the Al precursor and ammonia (NH3) with and without plasma activation as the N precursor in the temperature range from 100 to 400 °C while monitoring the surface reactions using mass spectrometry. Our results, combined with recent quantum chemical modelling, suggest that the surface chemistry of the deposition process is chemisorption of TMA followed by reductive elimination of the methyl groups to render mono methyl aluminum species. The NH3 chemisorption is done by ligand exchange to form CH4 and an –NH2 terminated surface.

Graphical abstract: Surface chemistry in atomic layer deposition of AlN thin films from Al(CH3)3 and NH3 studied by mass spectrometry

Supplementary files

Article information

Article type
Paper
Submitted
07 Cax 2024
Accepted
17 Qad 2024
First published
17 Qad 2024
This article is Open Access
Creative Commons BY license

J. Mater. Chem. C, 2024,12, 12818-12824

Surface chemistry in atomic layer deposition of AlN thin films from Al(CH3)3 and NH3 studied by mass spectrometry

P. Mpofu, H. Hafdi, P. Niiranen, J. Lauridsen, O. Alm, T. Larsson and H. Pedersen, J. Mater. Chem. C, 2024, 12, 12818 DOI: 10.1039/D4TC01867B

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements