| 摘要 |
The invention relates to a process and to an apparatus for coating a substrate with inhomogeneous layers. The invention is intended to provide a simple and economical solution to this problem. For this purpose, the substrate (15) is first exposed in a plasma reactor (1) to the atmosphere of a base gas, for example silane SiH4. In a plasma discharge, this base gas is decomposed and deposits on the substrate. This base gas is mixed with one or more further gases such as, for example, nitrogen and ammonia which, by reaction with the gas components of the base gas, deposit on the substrate as amorphous, non-stoichiometric compounds. By varying the proportions of base gas and admixed gases, the coating deposited on the substrate is thus provided with physical properties which are variable across the thickness of the coating. The process is particularly suitable for surface blooming of optical elements such as lenses or the like over a wavelength range which is wide as compared with the conventional interference layers and can also be used in the infrared region and, in addition, for decorative staining of metal objects or plastic objects, for example spectacle frames. By means of such inhomogeneous blooming, the refractive index of the coating can be continuously reduced, for example from about 4 to about 1.5 and less. <IMAGE>
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