Chemical Vapor Deposition involves a chemical reaction which transforms molecules in a gas form called precursor, which react and/or decompose into a solid material in the form of thin film or powder on the surface of a substrate. Frequently volatile by-products are also produced, which are removed by gas flow through the reaction chamber. This method is widely used in the semiconductor industry. This process is used both in the critical “front-end” gate formation and “back-end” in between the metal connecting layers in semiconductor manufacturing.