Patents Represented by Attorney, Agent or Law Firm Robert J. Stein
  • Patent number: 6825618
    Abstract: Apparatus and method for inductively coupling electrical power to a plasma in a semiconductor process chamber. In a first aspect, an array of wedge-shaped induction coils are distributed around a circle. The sides of adjacent coils are parallel, thereby enhancing the radial uniformity of the magnetic field produced by the array. In a second aspect, electrostatic coupling between the induction coils and the plasma is minimized by connecting each induction coil to the power supply so that the turn of wire of the coil which is nearest to the plasma is near electrical ground potential. In one embodiment, the hot end of one coil is connected to the unbalanced output of an RF power supply, and the hot end of the other coil is connected to electrical ground through a capacitor which resonates with the latter coil at the frequency of the RF power supply.
    Type: Grant
    Filed: May 20, 2003
    Date of Patent: November 30, 2004
    Inventors: Bryan Y. Pu, Hongching Shan, Claes Bjorkman, Kenny Doan, Mike Welch, Richard Raymond Mett