Skip to main content
SLU publication database (SLUpub)

Research article2020Peer reviewedOpen access

In Situ Activation of an Indium(III) Triazenide Precursor for Epitaxial Growth of Indium Nitride by Atomic Layer Deposition

O'Brien, Nathan J.; Rouf, Polla; Samii, Rouzbeh; Ronnby, Karl; Buttera, Sydney C.; Hsu, Chih-Wei; Ivanov, Ivan G.; Kessler, Vadim; Ojamae, Lars; Pedersen, Henrik

Abstract

Indium nitride (InN) is characterized by its high electron mobility, making it a ground-breaking material for high frequency electronics. The difficulty of depositing high-quality crystalline InN currently impedes its broad implementation in electronic devices. Herein, we report a new highly volatile In(III) triazenide precursor and demonstrate its ability to deposit high-quality epitaxial hexagonal InN by atomic layer deposition (ALD). The new In(III) precursor, the first example of a homoleptic triazenide used in a vapor deposition process, was easily synthesized and purified by sublimation. Thermogravimetric analysis showed single step volatilization with an onset temperature of 145 degrees C and negligible residual mass. Strikingly, two temperature intervals with self-limiting growth were observed when depositing InN films. In the high-temperature interval, the precursor underwent a gas-phase thermal decomposition inside the ALD reaction chamber to produce a more reactive In(III) compound while retaining self-limiting growth behavior. Density functional theory calculations revealed a unique two-step decomposition process, which liberates three molecules of each propene and N-2 to give a smaller tricoordinated In(III) species. Stoichiometric InN films with very low levels of impurities were grown epitaxially on 4H-SiC. The InN films deposited at 325 degrees C had a sheet resistivity of 920 Omega/sq. This new triazenide precursor enables ALD of InN for semiconductor applications and provides a new family of M-N bonded precursors for future deposition processes.

Published in

Chemistry of Materials
2020, Volume: 32, number: 11, pages: 4481-4489 Publisher: AMER CHEMICAL SOC

    UKÄ Subject classification

    Materials Chemistry

    Publication identifier

    DOI: https://doi.org/10.1021/acs.chemmater.9b05171

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/106888