Coating processes – Measuring – testing – or indicating – Thickness or uniformity of thickness determined
Patent
1997-01-22
2000-02-15
Padgett, Marianne
Coating processes
Measuring, testing, or indicating
Thickness or uniformity of thickness determined
427569, 427575, 427164, 427166, 427167, 427162, 427579, H05H 100
Patent
active
060250135
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a procedure for determining the process parameters for a plasma impulse chemical vapor deposition (PICVD) process for the production of coatings with a uniform thickness of layers on curved substrates, especially on lenses made of glass or plastics where the substrate surface to be coated is situated opposite the gas emitting surface of a gas showerhead, through which gas mixtures containing the gas forms the coating stream into a reaction chamber where separate plasma impulses are generated through timed impulse pauses.
BACKGROUND
From DE 40 08 405 C1, a microwave PICVD process for the production of a cold light reflector on the interior side of dome shaped substrates is known, which may also consist of plastics. In order to achieve a uniform thickness of coatings, a gas showerhead adapted to the contour of the surface is suggested, among other things. The known process only generally hints at how a curved substrate could be coated uniformly. If a substrate with different surface curvature should be coated--there are more than 10,000 different examples--then this process is not useful for economic reasons because of the multitude of different gas showerheads.
FR 26 77 841 describes a microwave plasma chemical vapor deposition (CVD) reactor for the production of safety and filter coatings on optical plastics substrates, such as lenses. The substrate lies on the electrode of a 13.56 MHz generator with a bias voltage. Oxygen is stimulated by a 2.45 gigahertz microwave field, which in turn stimulates the reaction partner, which is supplied at a remote location and contains silicium. As a consequence, a coating is formed on the substrate. The back side of the substrate is protected from undesired coating by an antibody, which is adapted to the form, and as a result, this process is uneconomical with substrates with different surface curvatures because of the multitude of required antibodies. FR 26 77 841 does not disclose how to attain uniformity with this approach.
DE 41 42 877 A1 describes a CVD process and a device for the coating of semiconductor wafers with uniform thickness. Uniformity is achieved by using a gas showerhead that has several individual gas blow areas. The gas showerhead is situated opposite the substrate and covered by a closed hood, which distributes the coating gas to the substrate rotationally symmetrically. The first and second gas blower area must be on a common level to ensure that a coating of high quality and uniform density can be formed, and it is therefore unlikely that this process can be used for the uniform coating of curved surfaces. A second disadvantage of this approach is the relative slowness of the coating process. Only a low uniformity of .+-.5% can be achieved, which is insufficient for the production of antireflection coatings. No suggestion concerning the coating of curved substrates with or without use of rotation symmetry is provided, and no measures are mentioned regarding how the backside of such substrates could be protected from the coating process.
DE 39 31 713 C1 describes a process and a device for simultaneous CVD coating from all sides of curved substrates in a 13.56 Megahertz Plasma. According to DE 39 31 713 C1, no difference can be detected in the thickness of the coating from the center to the periphery using this process. However, no measurement accuracy is provided. The process only refers to the precipitation of scratch resistant layers for which requirements for uniformity are much lower than for precipitation of anti-reflection reflection layers. The adaptability of this process for the production of anti-reflection coatings is neither disclosed nor suggested by this reference.
DE 34 13 019 A1 describes a plasma CVD process for the production of a scratch resistant layer to transparent plastics elements through polymerization of hexamethyldisiloxane (HMDSO) or other organic compounds containing silicium, whereby good adhesion with superior surface hardness are achieved through a continuo
REFERENCES:
patent: 4481229 (1984-11-01), Suzuki et al.
patent: 4500563 (1985-02-01), Ellenberger
patent: 4935661 (1990-06-01), Heinecke et al.
patent: 4962727 (1990-10-01), Harada
patent: 4973883 (1990-11-01), Hirose
patent: 4981722 (1991-01-01), Moller et al.
patent: 5154943 (1992-10-01), Etzkorn et al.
patent: 5180436 (1993-01-01), Ueda et al.
patent: 5192717 (1993-03-01), Kawakami et al.
patent: 5227202 (1993-07-01), Thieband et al.
patent: 5236636 (1993-08-01), Tisack
patent: 5272360 (1993-12-01), Todoroki et al.
patent: 5449880 (1995-09-01), Takaki
patent: 5455061 (1995-10-01), Matossian et al.
Patent Abstracts of Japan Pub. No. JP4293235 vol. 17, No. 110 (E-1329) pub. date Oct. 16, 1992.
Klug, W., Schneider, R., and Zoller, A. "Plasma Enhanced CVD Hard Coatings for Ophtalmic Optics." 1990, No month.
Heming, M., Hochhaus, R., Otto, J., and Segner, J. "Plasma Impluse Chemical Vapour Deposition--A Novel Technique for Optical Coatings". Tuscon 1992, No month.
Heming Martin
Lange Ulrich
Langfeld Roland
Mohl Wolfgang
Otto Jurgen
Padgett Marianne
Schott Glaswerke
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