| 摘要 |
<p>A PCVD process is disclosed for producing coating layers of uniform thickness on domed substrates. The substrate surface to be coated is arranged in relation to the gas passage surface of a gas shower. In order to determine the appropriate processing parameters, in a first series of tests for one type of substrate to be coated the size of the gas passage surfaces and gas mass flows through the gas passage surfaces are kept constant while the intervals between plasma impulses are gradually modified, starting from an initial value tA until an optimum value teff is determined and until the uniformity of the thickness profile of the layers generated on the substrate may no longer be improved. If required, during a second series of tests the value teff may be kept constant while the thickness profile of the layers is further modified by further optimising the local parameters and/or the gas mass flows until its uniformity may no longer be improved. The device has a gas shower (10) subdivided into zones and whose gas passage surfaces (11) are arranged in relation to a substrate to be coated (1). The zones (13, 14 and 15) are connected by supply lines (21, 21a and 22) to a source of non film-forming gas (27) and to a gas source (28) that supplies fresh gas.</p> |
