Abstract: A method is disclosed for introducing into a chemical vapor deposition chamber precursors of elements to be deposited over a heated substrate. The method comprises the steps of maintaining one or more precursors in liquid form or in solution at a pressure higher than the pressure of the chamber; injecting periodically and under control in the deposition chamber precursor droplets each of the droplets having a controllable volume; volatizing the injected precursor droplets to produce evaporated precursors, and conveying toward the substrate the evaporated precursors at a temperature and pressure of the chamber, whereby the evaporated precursors react to produce the elements deposited onto the substrate.