Principles of precursor design for vapour deposition methods

Chemical vapour deposition (CVD) and atomic layer deposition (ALD) are attractive techniques for depositing a wide spectrum of thin solid film materials, for a broad spectrum of industrial applications. These techniques rely on volatile, reactive, and thermally stable molecular precursors to transport and deposit growth materials in a kinetically controlled manner, resulting in uniform, conformal, high purity films. Developments in these fields depend on careful precursor design. We discuss the qualities that make successful CVD or ALD precursors (low melting point, high volatility, stability and specific reactivity) and the widely applicable design principles used to achieve them, through examples of group 11 and 13 precursors including amidinates, guanidinates and iminopyrrolidinates. We highlight the most valuable techniques that we use to asses potential precursors on the basis of the discussed qualities, and to elucidate relevant mechanisms of decomposition and surface reactivity. There is a strong focus on thermogravimetric analysis (TGA), and solid state (SS) and solution NMR studies.

Precursor design is central to the advancement of CVD and ALD technologies. These thin film deposition techniques rely on molecular precursors which have low melting points, high volatility, stability and specific reactivity. These properties are discussed through examples of group 11 and 13 precursors.Figure optionsDownload as PowerPoint slide