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The chamber walls are at room temperature.

Cold wall CVD – CVD in which only the substrate is directly heated either by induction or by passing current through the substrate itself or a heater in contact with the substrate.

Hot wall CVD – CVD in which the chamber is heated by an external power source and the substrate is heated by radiation from the heated chamber walls.

Classified by type of substrate heating:.

High growth rates can be reached using this technique. This technique is suitable for use on liquid or solid precursors. The precursor vapors are then transported to the substrate as in classical CVD.

Liquid solutions are injected in a vaporization chamber towards injectors (typically car injectors).

Direct liquid injection CVD (DLICVD) – CVD in which the precursors are in liquid form (liquid or solid dissolved in a convenient solvent).This technique is suitable for use with non-volatile precursors. Aerosol assisted CVD (AACVD) – CVD in which the precursors are transported to the substrate by means of a liquid/gas aerosol, which can be generated ultrasonically.Classified by physical characteristics of vapor:.Most modern CVD is either LPCVD or UHVCVD. Uses tetraethyl orthosilicate (TEOS) and Ozone to fill high aspect ratio Si structures with silicon dioxide (SiO 2). Sub-atmospheric CVD (SACVD) – CVD at sub-atmospheric pressures.Note that in other fields, a lower division between high and ultra-high vacuum is common, often 10 −7 Pa. Ultrahigh vacuum CVD (UHVCVD) – CVD at very low pressure, typically below 10 −6 Pa (≈10 −8 torr).Reduced pressures tend to reduce unwanted gas-phase reactions and improve film uniformity across the wafer. Low-pressure CVD (LPCVD) – CVD at sub-atmospheric pressures.Atmospheric pressure CVD (APCVD) – CVD at atmospheric pressure.These processes generally differ in the means by which chemical reactions are initiated. CVD is practiced in a variety of formats.