Atomic Layer Deposition of Pt Thin Films Using Dimethyl (<i>N</i>,<i>N</i>-Dimethyl-3-Butene-1-Amine-<i>N</i>) Platinum and O₂ Reactant

Abstract

Pt thin films, using the Pt precursor, dimethyl(N,N-dimethyl-3-butene-1-amine-N)platinum (DDAP, C8H19NPt), were deposited by atomic layer deposition (ALD). The growth characteristics of the Pt thin films were systemically investigated. A saturated growth rate was obtained with an increase in precursor and reactant pulse times, revealing the nature of the ALD self-limiting process. The growth rate increased with increasing deposition temperature and finally became saturated above 280 °C, showing a high growth rate of 0.85 Å/cycle. The short incubation time for Pt nucleation promoted the growth characteristics, which can be favorable for catalytic applications. The high reactivity and small adsorbate size produced the relatively high growth rate of the Pt thin films deposited with the DDAP precursor. A very low resistivity, close to the value of bulk Pt, was obtained for all Pt thin films deposited at various temperatures. The low resistivity was due to the similar crystalline structure and very high purity of the Pt thin films at all deposition temperatures explored in this study. In addition, Pt thin films were also deposited on a high-aspect-ratio substrate and showed good uniformity and step coverage, with a constant work function, which can be promising for electrode applications. Synthesis of Pt films by ALD using the DDAP Pt precursor and O2 is a noteworthy approach for obtaining films with a high growth rate and low resistivity.