(JP7230960-A)      Plasma chemical vapour deposition appts. includes a chamber contg. a holding electrode on which a substrate is mounted and opposite to it an electrode to which high frequency power is supplied. The substrate is provided with a heater so that a reactant gas passed between it and the application electrode is decomposed by a glow discharge and a deposit formed on the substrate. A first heater is mounted peripherally on the application electrode which is also heated by a second heater comprising a base portion below and parallel to the electrode and a side wall extending upwardly from the periphery of the base to surround the electrode but spaced from it. The second electrode heats both the periphery of the application electrode and its face remote from the substrate. pref. both of the heaters maintain the electrode at not less than 100C. The application electrode may be circular to rectangular, with the base of the second heater of similar shape but larger. There is independently claimed an appts. similar to that above, except that the application electrode is provided with a heater characterised only in that it heats at least the periphery of the electrode to prevent unwanted deposition.    USE -   Solar cells, photo-conductive drums, sensors, thin film transistors.    ADVANTAGE -   High power input can be used to increase deposition rate without unwanted deposition of polysilane powder.    (US5487786-A)      A plasma CVD device having within a deposition chamber: a substrate holding electrode for holding a substrate; a high frequency application electrode arranged opposite to and parallel to the substrate held by the substrate holding electrode; a high frequency power supply for applying high frequency power to the high frequency application electrode; and a substrate heater for heating the substrate held by the substrate holding electrode, where a material gas introduced between the substrate holding electrode and the high frequency application electrode is decomposed by glow discharge generated by a high frequency power applied between the two electrodes, so that a thin film is deposited on the heated substrate, the plasma CVD device comprising: a first electrode heater installed along a peripheral portion of the high frequency application electrode, and heating the peripheral portion of the high frequency application electrode; and a second metallic electrode heater which is composed of a bottom portion and a side portion provided uprightly along a peripheral edge of the bottom portion and formed into a concave shape in section, and which surrounds the high frequency application electrode with a spacing between them, and which heats a surface of the high frequency application electrode opposite to its surface facing the substrate as well as the peripheral portion of the high frequency application electrode.    (EP659905-B1)      Plasma chemical vapour deposition appts. includes a chamber contg. a holding electrode on which a substrate is mounted and opposite to it an electrode to which high frequency power is supplied. The substrate is provided with a heater so that a reactant gas passed between it and the application electrode is decomposed by a glow discharge and a deposit formed on the substrate. A first heater is mounted peripherally on the application electrode which is also heated by a second heater comprising a base portion below and parallel to the electrode and a side wall extending upwardly from the periphery of the base to surround the electrode but spaced from it. The second electrode heats both the periphery of the application electrode and its face remote from the substrate. pref. both of the heaters maintain the electrode at not less than 100C. The application electrode may be circular to rectangular, with the base of the second heater of similar shape but larger. There is independently claimed an appts. similar to that above, except that the application electrode is provided with a heater characterised only in that it heats at least the periphery of the electrode to prevent unwanted deposition.    USE -   Solar cells, photo-conductive drums, sensors, thin film transistors.    ADVANTAGE -   High power input can be used to increase deposition rate without unwanted deposition of polysilane powder.