| 摘要 |
A method of depositing a thin film on the surface of a substrate using a microwave plasma assisted chemical deposition technique consists in directing the gaseous reaction mixture towards the surface through a multiplicity of perforations in a plate spaced from and substantially parallel to the surface while a microwave plasma is produced between the plate and substrate, so as to cause a chemical reaction to take place and form said film on the surface. The substrate may be silica and glass may be deposited on the substrate as a first film in a desired pattern, eg by selective removal of part of the film after deposition to leave the pattern remaining, and a second film of glass, having a lower refractive index, is subsequently deposited on the first film. Metal and silica (doped with undoped) films may also be deposited. The method is intended primarily for depositing thin optical waveguiding films for use in integrated optics but other applications such as in semiconductors and integrated circuits are evisaged. Apparatus for depositing films as illustrated in Fig. 2 consists of a silica outer tube 4, a silica inner tube 2 having an external diameter slightly less than the internal diameter of a main portion of the outer tube, the inner tube being closed at one end by a silica plate 6, on which the substrate is placed, a dispenser tube in the shape of a funnel closed at its wider end by a perforated disc 7 and terminating at the opposite end in a narrow inlet portion 8 having an external diameter which is smaller than the internal diameter of a neck portion 5 of the outer tube and an O- ring vacuum seal 12 formed between the inner tube 2 and the main portion 4 of the outer tube 1. <IMAGE>
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