Low-temperature ALD of highly conductive antimony films through the reaction of silylamide with alkoxide and alkylamide precursors

Antimony (Sb) has distinct physical properties that make it a promising candidate for use in integrated phase-change photonics and tunable optical absorbers. In this work, we present atomic layer deposition (ALD) of Sb metal thin films using new precursor combinations produced from comproportionation reactions of antimony ethoxide (Sb(OEt)3) and Tris (dimethylamido)antimony (Sb(NMe2)3) with Tris (trimethylsilyl)antimony ((SiMe3)3Sb). The growth behaviors of the Sb thin films made from the Sb(OEt)3/(SiMe3)3Sb and Sb(NMe2)3/(SiMe3)3Sb precursor combinations showed different temperature dependencies at low deposition temperatures (60–80 °C). Furthermore, the deposition temperature had a significant impact on the oxidation of the deposited Sb film after exposure to air. XRD and Raman spectroscopy confirmed the high purity of the Sb films made with the Sb(OEt)3/(SiMe3)3Sb combination and deposited at 75 °C. The presence of a Sb2O3 phase deteriorated the electrical properties of deposited Sb films. However, the electrical conductivities of the purest Sb films prepared in this study were slightly higher than those previously reported for Sb-ALD films. This approach of Sb ALD can speed up actual applications of pure metals in electronic device fabrication and can potentially be extended to other main group metals.