Flame Assisted CVD

Flame assisted chemical vapour deposition (FACVD) is a low cost, relatively simple atmospheric pressure CVD technique that is compatible with both small volume, batch, and high volume continuous coating processes. Use of this method with low hazard aqueous solutions of simple metal salts can yield metal oxide thin films, which represents a major advantage in terms of precursor cost and environmental impact compared to alternative CVD methods.

Atmospheric pressure chemical vapour deposition (APCVD) processes have a number of advantages over other, reduced pressure CVD techniques such as low pressure chemical vapour deposition (LPCVD) and plasma enhanced chemical vapour deposition (PECVD), including their suitability for high volume, continuous growth processes, the high growth rates achievable, the ease with which the CVD equipment may be retro-fitted to an existing, open production line and the conformal nature of the layers deposited Of particular interest is flame assisted chemical vapour deposition (FACVD) in which a flame is used to provide the energy required to crack the precursor species into fragments which subsequently form the film upon the substrate.

One advantage of this technique is that no closed reaction cell is required, so making it ideal for fitting on open production lines. However, as an open-air process, the FACVD process may be contaminated by atmospheric impurities, which can lead to contamination within the desired film. In previous studies, we have demonstrated that FACVD may be used with precursors in the form of simple, readily available, low cost metal salts in aqueous solution of (for example) silver, copper, tungsten and molybdenum. The use of aqueous solutions in this manner is particularly noteworthy in terms of the likely environmental impact of the FACVD process and its general ease of use.