Chemical Vapour Deposition (CVD) method: This method is based on the crystallization of reactants in the vapor or gas phase. In this method, volatile starting materials are mixed at a suitable temperature and the solid products are crystallized out. Sometimes the volatile compounds are passed through the reaction vessels with an inert carrier gas. Typical volatile materials include among others, hydrides, halides, organo-metallic compounds etc.
Semiconductors by Chemical Vapor Deposition
AsCl3 + Ga + 3/2 H2 → GaAs + 3 HCl
SiCl4 + 2 H2 → Si + 4 HCl
SiH4 → Si + 2 H2
- Diamond films are made by CVD at low pressure and below 1300 K by heating gas mixtures (methane or acetylene and hydrogen), or by breaking down the mixtures with microwaves.
- The carbon atoms and carbon-containing radicals are deposited onto a substrate.
- It is also possible to deposit monocrystalline layers onto a seed diamond, building a larger diamond layer by layer.