Recent advances in chemical vapor deposition

Chemical vapor deposition (CVD) represents the method-of-choice for thin film growth, as well as nanomaterials such as carbon nanotubes. Distinct advantages of this technique include low cost, and strict control over the resultant film stoichiometry, morphology, and thickness. The most critical component of a CVD process is the precursor that is employed. Hence, there has been a continuing interest in the development of new CVD precursors that would be useful for a range of thin film applications. This review will highlight recent advances in CVD precursor design, including both single-source and co-reactant precursor systems. Whereas the earliest examples of CVD precursors included metal beta-diketonates, this review will feature novel ligand systems that have already been used, or have been proposed for future MOCVD applications. In addition, we will describe new methodologies that have improved the deposition process through innovations in precursor delivery and decomposition within the CVD system. These latter developments have extended the scope of CVD applications to include precursors that are not particularly volatile, and have allowed for a reduction in the level of impurities in the growing film.