Infra red transparent optical components.

摘要

A method of coating a substrate in a glow discharge chamber uses a source of hydrocarbon and another element. For example butane and germane are used to deposit a coating of GexC1-x where 0 < x < 1 onto a germanium substrate. The substrate temperature is maintained above 400 DEG C typically 530 DEG C during growth to prevent inclusion of H2 in the coating. The presence of Ge in the coating allows thick, strain free, layers to be grown. Alternatively butane and silane may be used to deposit SixC1-x. Varying the proportions of the hydrocarbon and germane or silane allows a variation in the value of x.