Patent ID: 8002947

Claim:
A plasma treatment system comprising: a chamber; a first frequency power source; a movement mechanism; an electrode structure within the chamber, the electrode structure comprising: a first electrode being supplied with a first frequency power of a high frequency from the first frequency power source, which is fixed to an upper portion of the chamber; and a second electrode having a substrate stage and being moved by the movement mechanism between an upper position and a lower position determined within the chamber; an insulator ring covering a whole round inside of a cylindrical side-wall of the chamber, a length of the insulator ring being at least 3 cm downward along the inside of the side-wall from a main surface of the first electrode, which is projected into an inner space of the chamber; and a control means for: controlling the movement mechanism to move the second electrode to the upper position to form a first gap of 1 to 2 cm between the first electrode and the second electrode as a first constriction with a first conductance of a gas flow and to form a second gap of not more than 5 mm between the insulator ring and the second electrode as a second constriction with a second conductance of the gas flow that is sufficiently small to provide a symmetrical flow of gas in the first gap, depositing a film on a substrate placed on the substrate stage by a first density plasma in the first gap, starting a cleaning step by a second density plasma in the first gap after forming the film, unloading the substrate, and controlling the movement mechanism to move the second electrode to the upper position to form the first gap, controlling the movement mechanism to move the second electrode downward so as to make a third gap, which is between a peripheral edge of the second electrode facing the inside of the side-wall of the chamber and the side-wall of the chamber, larger than the second gap after the starting of the cleaning step, making the symmetrical flow of gas when generating the plasma in the first gap, and using plasma whose density is lower than the second density plasma to carry out the cleaning step when making the third gap.