Patent ID: 7032536

Claim:
A thin film formation apparatus for forming a thin film on a substrate, comprising: a reaction chamber; a gas introduction section for introducing a reactant gas into the reaction chamber; an evacuation section for exhausting the reactant gas from the reaction chamber; first and second planar electrodes provided in the reaction chamber; first and second support members which respectively support the first and second electrodes in parallel relation; a high frequency power source for applying high frequency power between the first and second electrodes; and a heating section for heating one of the first and second electrodes; wherein the substrate is placed on the heated electrode, and wherein at least one of the first and second electrodes is supported movably in a lateral direction of thermal expansion by the corresponding support member, and wherein said corresponding support member has a protruding stop portion that does not engage said one electrode at room temperature thereby permitting said one electrode to expand laterally toward the stop portion at high temperatures so as to allow for thermal expansion of said one electrode.