Chemical vapor deposition (CVD) is a chemical process used to produce high-purity, high-performance solid materials. The process is often used in the semiconductor industry to produce thin films. In a typical CVD process, the wafer (substrate) is exposed to one or more volatile precursors, which react and/or decompose on the substrate surface to produce the desired deposit. Frequently, volatile by-products are also produced, which are removed by gas flow through the reaction chamber. CVD is practiced in a variety of formats. In IEN cleanroom, Plasmas Enhanced Chemical Vapor Deposition (PECVD) and Low Pressure Chemical Vapor Deposition (LPCVD) are available.